Nonmelanoma Skin Cancer

The Diagnosis: Dermatofibrosarcoma Protuberans

Histopathologic examination showed a dermal tumor composed of spindle cells in a storiform arrangement (Figure 1). Immunohistochemistry demonstrated positive CD34 staining of the tumoral cells (Figure 2). Clinical review, histopathologic examination, and immunohistochemistry confirmed a diagnosis of dermatofibrosarcoma protuberans (DFSP). The patient underwent Mohs micrographic surgery (MMS) with clear margins after 3 stages, followed by repair with a rotation flap. No evidence of recurrence was found at 4-year follow-up.

Dermatofibrosarcoma protuberans is a rare low-grade sarcoma of fibroblast origin with an annual incidence of 0.8 to 5 cases per million individuals.¹ It typically presents in patients aged 30 to 50 years on the trunk, scalp, or proximal extremities as an asymptomatic, flesh-colored, erythematous or brown, indurated plaque or nodule.² Due to its variable presentation, these lesions often may be misdiagnosed as lipomas or epidermoid cysts, preventing proper targeted treatment. Therefore, suspicious enlarging indurated nodules require a lower threshold for biopsy.¹

A definitive diagnosis of DFSP is achieved after a biopsy and histopathologic evaluation. Hematoxylin and eosin staining typically shows diffuse infiltration of the dermis and the subcutaneous fat by densely packed, cytologic, relatively uniform, spindle-shaped tumor cells arranged in a characteristic storiform shape. Tumor cells are spread along the septae of the subcutaneous fatty tissue.³ Immunohistochemistry is characterized by positive CD34 and negative factor XIIIa, with rare exceptions.

The differential diagnosis includes lipoma, epidermoid cyst, plexiform fibrohistiocytic tumor, and malignant peripheral nerve sheath tumor.³ Positive CD34 immunostaining, negative S-100 staining, and a storiform pattern of spindle cells can assist in differentiating DFSP from these possible differential diagnoses; lesions of these other entities are characterized by different pathologic findings. Lipomas are composed of fat tissue, epidermoid cysts have epithelial-lined cysts filled with keratin, plexiform fibrohistiocytic tumors have plexiform rays of fibrous tissue extending into fat with negative CD34 staining, and malignant peripheral nerve sheath tumors have fleshy variegated masses involving the peripheral nerve trunks with partial S-100 staining.^4-7 Additional evaluation to confirm DFSP can be accomplished by analysis of tumor samples by fluorescence in situ hybridization or reverse transcriptase–polymerase chain reaction to detect chromosomal translocations and fusion gene transcripts, as chromosomal translocations may be found in more than 90% of cases.³

Early diagnosis of DFSP is beneficial, as it can help prevent recurrence as well as metastasis. Studies have attempted to document the risk for recurrence as well as metastasis based on characteristic features and treatment strategies of DFSP. In a study of 186 patients, 3 had metastatic disease to the lungs, the most common site of metastasis.⁸ These 3 patients had fibrosarcomatous transformation within DFSP, emphasizing the importance of detailing this finding early in the diagnosis, as it was characterized by a higher degree of cellularity, cytologic atypia, mitotic activity, and negative CD34 immunostaining.⁹ In patients with suspected metastasis, lymph node ultrasonography, chest radiography, and computed tomography may be utilized.³

When treating DFSP, the goal is complete removal of the tumor with clear margins. Mohs micrographic surgery, modified MMS, and wide local excision (WLE) with 2- to 4-cm margins are appropriate treatment options, though MMS is the treatment of choice. A study comparing MMS and WLE demonstrated 3% and 30.8% recurrence rates, respectively.⁸ In MMS, complete margin evaluation on microscopy is performed after each stage to ensure negative surgical margins. The presence of positive surgical margins elicits continued resection until the margins are clear.^10,11

Other treatment modalities may be considered for patients with DFSP. Molecular therapy with imatinib, an oral tyrosine kinase inhibitor targeting platelet-derived growth factor–regulated expression, can be utilized for inoperable tumors; however, additional clinical trials are required to ensure efficacy.³ Surgical removal of the possible remaining tumor is still recommended after molecular therapy. Radiotherapy is an additional method of treatment that may be used for inoperable tumors.³

Dermatofibrosarcoma protuberans is a rare lowgrade sarcoma of fibroblast origin that typically does not metastasize but often has notable subclinical extension and recurrence. Differentiating DFSP from other tumors often may be difficult. A protuberant, flesh-colored, slowgrowing, and asymptomatic lesion often may be confused with lipomas or epidermoid cysts; therefore, biopsies with immunohistostaining for suspicious lesions is required.¹² Mohs micrographic surgery has evolved as the treatment of choice for this tumor, though WLE and new targeted molecular therapies still are considered. Proper diagnosis and treatment of DFSP is paramount in preventing future morbidity.

The Diagnosis: Dermatofibrosarcoma Protuberans

Histopathologic examination showed a dermal tumor composed of spindle cells in a storiform arrangement (Figure 1). Immunohistochemistry demonstrated positive CD34 staining of the tumoral cells (Figure 2). Clinical review, histopathologic examination, and immunohistochemistry confirmed a diagnosis of dermatofibrosarcoma protuberans (DFSP). The patient underwent Mohs micrographic surgery (MMS) with clear margins after 3 stages, followed by repair with a rotation flap. No evidence of recurrence was found at 4-year follow-up.

Dermatofibrosarcoma protuberans is a rare low-grade sarcoma of fibroblast origin with an annual incidence of 0.8 to 5 cases per million individuals.¹ It typically presents in patients aged 30 to 50 years on the trunk, scalp, or proximal extremities as an asymptomatic, flesh-colored, erythematous or brown, indurated plaque or nodule.² Due to its variable presentation, these lesions often may be misdiagnosed as lipomas or epidermoid cysts, preventing proper targeted treatment. Therefore, suspicious enlarging indurated nodules require a lower threshold for biopsy.¹

A definitive diagnosis of DFSP is achieved after a biopsy and histopathologic evaluation. Hematoxylin and eosin staining typically shows diffuse infiltration of the dermis and the subcutaneous fat by densely packed, cytologic, relatively uniform, spindle-shaped tumor cells arranged in a characteristic storiform shape. Tumor cells are spread along the septae of the subcutaneous fatty tissue.³ Immunohistochemistry is characterized by positive CD34 and negative factor XIIIa, with rare exceptions.

The differential diagnosis includes lipoma, epidermoid cyst, plexiform fibrohistiocytic tumor, and malignant peripheral nerve sheath tumor.³ Positive CD34 immunostaining, negative S-100 staining, and a storiform pattern of spindle cells can assist in differentiating DFSP from these possible differential diagnoses; lesions of these other entities are characterized by different pathologic findings. Lipomas are composed of fat tissue, epidermoid cysts have epithelial-lined cysts filled with keratin, plexiform fibrohistiocytic tumors have plexiform rays of fibrous tissue extending into fat with negative CD34 staining, and malignant peripheral nerve sheath tumors have fleshy variegated masses involving the peripheral nerve trunks with partial S-100 staining.^4-7 Additional evaluation to confirm DFSP can be accomplished by analysis of tumor samples by fluorescence in situ hybridization or reverse transcriptase–polymerase chain reaction to detect chromosomal translocations and fusion gene transcripts, as chromosomal translocations may be found in more than 90% of cases.³

Early diagnosis of DFSP is beneficial, as it can help prevent recurrence as well as metastasis. Studies have attempted to document the risk for recurrence as well as metastasis based on characteristic features and treatment strategies of DFSP. In a study of 186 patients, 3 had metastatic disease to the lungs, the most common site of metastasis.⁸ These 3 patients had fibrosarcomatous transformation within DFSP, emphasizing the importance of detailing this finding early in the diagnosis, as it was characterized by a higher degree of cellularity, cytologic atypia, mitotic activity, and negative CD34 immunostaining.⁹ In patients with suspected metastasis, lymph node ultrasonography, chest radiography, and computed tomography may be utilized.³

When treating DFSP, the goal is complete removal of the tumor with clear margins. Mohs micrographic surgery, modified MMS, and wide local excision (WLE) with 2- to 4-cm margins are appropriate treatment options, though MMS is the treatment of choice. A study comparing MMS and WLE demonstrated 3% and 30.8% recurrence rates, respectively.⁸ In MMS, complete margin evaluation on microscopy is performed after each stage to ensure negative surgical margins. The presence of positive surgical margins elicits continued resection until the margins are clear.^10,11

Other treatment modalities may be considered for patients with DFSP. Molecular therapy with imatinib, an oral tyrosine kinase inhibitor targeting platelet-derived growth factor–regulated expression, can be utilized for inoperable tumors; however, additional clinical trials are required to ensure efficacy.³ Surgical removal of the possible remaining tumor is still recommended after molecular therapy. Radiotherapy is an additional method of treatment that may be used for inoperable tumors.³

Dermatofibrosarcoma protuberans is a rare lowgrade sarcoma of fibroblast origin that typically does not metastasize but often has notable subclinical extension and recurrence. Differentiating DFSP from other tumors often may be difficult. A protuberant, flesh-colored, slowgrowing, and asymptomatic lesion often may be confused with lipomas or epidermoid cysts; therefore, biopsies with immunohistostaining for suspicious lesions is required.¹² Mohs micrographic surgery has evolved as the treatment of choice for this tumor, though WLE and new targeted molecular therapies still are considered. Proper diagnosis and treatment of DFSP is paramount in preventing future morbidity.

The Diagnosis: Dermatofibrosarcoma Protuberans

Histopathologic examination showed a dermal tumor composed of spindle cells in a storiform arrangement (Figure 1). Immunohistochemistry demonstrated positive CD34 staining of the tumoral cells (Figure 2). Clinical review, histopathologic examination, and immunohistochemistry confirmed a diagnosis of dermatofibrosarcoma protuberans (DFSP). The patient underwent Mohs micrographic surgery (MMS) with clear margins after 3 stages, followed by repair with a rotation flap. No evidence of recurrence was found at 4-year follow-up.

Dermatofibrosarcoma protuberans is a rare low-grade sarcoma of fibroblast origin with an annual incidence of 0.8 to 5 cases per million individuals.¹ It typically presents in patients aged 30 to 50 years on the trunk, scalp, or proximal extremities as an asymptomatic, flesh-colored, erythematous or brown, indurated plaque or nodule.² Due to its variable presentation, these lesions often may be misdiagnosed as lipomas or epidermoid cysts, preventing proper targeted treatment. Therefore, suspicious enlarging indurated nodules require a lower threshold for biopsy.¹

A definitive diagnosis of DFSP is achieved after a biopsy and histopathologic evaluation. Hematoxylin and eosin staining typically shows diffuse infiltration of the dermis and the subcutaneous fat by densely packed, cytologic, relatively uniform, spindle-shaped tumor cells arranged in a characteristic storiform shape. Tumor cells are spread along the septae of the subcutaneous fatty tissue.³ Immunohistochemistry is characterized by positive CD34 and negative factor XIIIa, with rare exceptions.

The differential diagnosis includes lipoma, epidermoid cyst, plexiform fibrohistiocytic tumor, and malignant peripheral nerve sheath tumor.³ Positive CD34 immunostaining, negative S-100 staining, and a storiform pattern of spindle cells can assist in differentiating DFSP from these possible differential diagnoses; lesions of these other entities are characterized by different pathologic findings. Lipomas are composed of fat tissue, epidermoid cysts have epithelial-lined cysts filled with keratin, plexiform fibrohistiocytic tumors have plexiform rays of fibrous tissue extending into fat with negative CD34 staining, and malignant peripheral nerve sheath tumors have fleshy variegated masses involving the peripheral nerve trunks with partial S-100 staining.^4-7 Additional evaluation to confirm DFSP can be accomplished by analysis of tumor samples by fluorescence in situ hybridization or reverse transcriptase–polymerase chain reaction to detect chromosomal translocations and fusion gene transcripts, as chromosomal translocations may be found in more than 90% of cases.³

Early diagnosis of DFSP is beneficial, as it can help prevent recurrence as well as metastasis. Studies have attempted to document the risk for recurrence as well as metastasis based on characteristic features and treatment strategies of DFSP. In a study of 186 patients, 3 had metastatic disease to the lungs, the most common site of metastasis.⁸ These 3 patients had fibrosarcomatous transformation within DFSP, emphasizing the importance of detailing this finding early in the diagnosis, as it was characterized by a higher degree of cellularity, cytologic atypia, mitotic activity, and negative CD34 immunostaining.⁹ In patients with suspected metastasis, lymph node ultrasonography, chest radiography, and computed tomography may be utilized.³

When treating DFSP, the goal is complete removal of the tumor with clear margins. Mohs micrographic surgery, modified MMS, and wide local excision (WLE) with 2- to 4-cm margins are appropriate treatment options, though MMS is the treatment of choice. A study comparing MMS and WLE demonstrated 3% and 30.8% recurrence rates, respectively.⁸ In MMS, complete margin evaluation on microscopy is performed after each stage to ensure negative surgical margins. The presence of positive surgical margins elicits continued resection until the margins are clear.^10,11

Other treatment modalities may be considered for patients with DFSP. Molecular therapy with imatinib, an oral tyrosine kinase inhibitor targeting platelet-derived growth factor–regulated expression, can be utilized for inoperable tumors; however, additional clinical trials are required to ensure efficacy.³ Surgical removal of the possible remaining tumor is still recommended after molecular therapy. Radiotherapy is an additional method of treatment that may be used for inoperable tumors.³

Dermatofibrosarcoma protuberans is a rare lowgrade sarcoma of fibroblast origin that typically does not metastasize but often has notable subclinical extension and recurrence. Differentiating DFSP from other tumors often may be difficult. A protuberant, flesh-colored, slowgrowing, and asymptomatic lesion often may be confused with lipomas or epidermoid cysts; therefore, biopsies with immunohistostaining for suspicious lesions is required.¹² Mohs micrographic surgery has evolved as the treatment of choice for this tumor, though WLE and new targeted molecular therapies still are considered. Proper diagnosis and treatment of DFSP is paramount in preventing future morbidity.

People with cancer are often desperate to know what caused their disease. Was it something they did? Something they could have prevented?

vitanovski/Thinkstock.com

In a recent analysis, experts estimated that about 40% of cancers can be explained by known, often modifiable risk factors. Smoking and obesity represent the primary drivers, though a host of other factors – germline mutations, alcohol, infections, or environmental pollutants like asbestos – contribute to cancer risk as well.

But what about the remaining 60% of cancers?

The study suggests that, although many of these cases likely have an underlying lifestyle or environmental component, experts still do not fully understand their origin story. And a small but significant number may simply be caused by chance.

Here’s what experts suspect those missing causes might be, and why they can be so difficult to confirm.
 

Possibility 1: Known risk factors contribute more than we realize

For certain factors, a straight line can be drawn to cancer.

Take smoking, for instance. Decades of research have helped scientists clearly delineate tobacco’s carcinogenic effects. Researchers have pinpointed a unique set of mutations in the tumors of smokers that can be seen when cells grown in a dish are exposed to the carcinogens present in tobacco.

In addition, experts have been able to collect robust data from epidemiologic studies on smoking prevalence as well as associated cancer risks and deaths, in large part because an individual’s lifetime tobacco exposure is fairly easy to measure.

“The evidence for smoking is incredibly consistent,” Paul Brennan, PhD, a cancer epidemiologist at the World Health Organization’s International Agency for Research on Cancer, said in an interview.

For other known risk factors, such as obesity and air pollution, many more questions than answers remain.

Because of the limitations in how such factors are measured, we are likely downplaying their effects, said Richard Martin, PhD, a professor of clinical epidemiology at the University of Bristol (England).

Take obesity. Excess body weight is associated with an increased risk of at least 13 cancers. Although risk estimates vary by study and cancer type, according to a global snapshot from 2012, being overweight or obese accounted for about 4% of all cancers worldwide – 1% in low-income countries and as high as 8% in high-income countries.

However, Dr. Brennan believes “we have underestimated the effect of obesity [on cancer].”

A key reason, he said, is most studies use body mass index to determine whether someone is overweight or obese, but BMI is a poor measure of body fat. BMI does not differentiate between fat and muscle, which means two people with the same height and weight can have the same BMI, even if one is an athlete who eats lean meats and vegetables while the other lives a sedentary life and consumes large quantities of processed foods and alcohol.

On top of that, studies often only calculate a person’s BMI once, and a single measurement can’t tell you how a person’s weight has fluctuated in recent years or across different stages of their life. However, recent analyses suggest that obesity status over time may be more relevant to cancer risk than one-off measures.

In addition, many studies now suggest that alterations to our gut microbes and high blood insulin level – often seen in people who are overweight or obese – may increase the risk of cancer and speed the growth of tumors.

When these additional factors are considered, the impact of excess body fat may ultimately play a much more significant role in cancer risk. In fact, according to Dr. Brennan, “if we estimate [the effects of obesity] properly, it might at some point become the main cause of cancer.”
 

Possibility 2: Environmental or lifestyle factors remain under the radar

Researchers have linked many substances we consume or are exposed to in our daily lives – air pollution, toxins from industrial waste, and highly processed foods – to cancer. But the extent or contribution of potential carcinogens in our surroundings, particularly those found almost everywhere at low levels, is still largely unknown.

One simple reason is the effects of many of these substances remain difficult to assess. For instance, it is much harder to study the impact of pollutants found in food or water, in which a given population will share similar exposure levels versus tobacco, where it is possible to compare a person who smokes a pack of cigarettes a day with a person who does not smoke.

“If you’ve got exposures that are ubiquitous, it can be difficult to discern their [individual] roles,” Dr. Martin said. “There are many causes that we [likely] don’t really know because everyone has been exposed.”

On the flip side, some carcinogenic substances that people encounter for limited periods might be missed if studies are not performed at the time of exposure.

“What’s in the body at age 40 may not reflect what you were exposed at age 5-10 on the playground or soccer field,” said Graham Colditz, MD, PhD, an epidemiologist and public health expert at Washington University, St. Louis. “The technology keeps changing so we can get better measures of what you’ve got exposure to today, but how that relates to 5, 10, 15 years ago is probably very variable.”

In addition, researchers have found that many carcinogens do not cause specific mutations in a cell’s DNA; rather, studies suggest that most carcinogens lead to cancer-promoting changes in cells, such as inflammation.

“We need to think of how potential carcinogens are causing cancer,” Dr. Brennan said. Instead of provoking mutations, potential carcinogens may use a “whole other kind of pathway.” When, for instance, inflammation becomes chronic, it may spur a cascade of events that ultimately leads to cancer.

Finally, not much is known about what causes cancers in low- and middle-income countries. Most of the research to date has been in high-income countries, such the United States, Australia, and parts of Europe.

“There’s a real lack of robust epidemiological studies in other parts of the world, Latin America, Africa, parts of Asia,” Marc Gunter, PhD, a molecular epidemiologist at the IARC, told this news organization.
 

Possibility 3: Some cancers occur by chance

When it comes to cancer risk, an element of chance may be at play. Cancer can occur in individuals who have very little exposure to known carcinogens or have no family history of cancer.

“We all know there are people who get cancer who eat very healthy diets, are never overweight, and never smoke,” Dr. Gunter said. “Then there are people on the other end of the extreme who don’t get cancer.”

But what fraction of cancers are attributable to chance?

A controversial 2017 study published in Science suggested that, based on the rate of cell turnover in healthy tissues in the lung, pancreas, and other parts of the body, only about one-third of cancers could be linked to environmental or genetic factors. The rest, the authors claimed, occurred because of random mutations that accumulated in a person’s DNA – in other words, bad luck.

That study brought on a flood of criticism from scientists who pointed to serious flaws in the work that led the researchers to significantly overestimate the share of chance-related cancers.

The actual proportion of cancers that occur by chance is much lower, according to Dr. Brennan. “If you look at international comparisons [of cancer rates] and take a conservative estimate, you see that maybe 10% or 15% of cancers are really chance.”

Whether some cancers are caused by bad luck or undiscovered risk factors remains an open question.

But the bottom line is many unknown causes of cancer are likely environmental or lifestyle related, which means that, in theory, they can be altered, even prevented.

“There is always going to be some element of chance, but you can modify your chance, depending on your lifestyle and maybe other factors, which we don’t fully understand yet,” Dr. Gunter said.

The good news is that, when it comes to prevention, there are many ways to modify our behaviors – such as consuming fewer processed meats, going for a daily walk, or getting vaccinated against cancer-causing viruses – to improve our chances of living cancer free. And as scientists better understand more about what causes cancer, possibilities for prevention will only grow.

“There is a constant, slow growth [in knowledge] that is lowering the overall risk of cancer,” Dr. Brennan said. “We’re never going to eliminate cancer, but we will be able to control it as a disease.”

A version of this article first appeared on Medscape.com.

People with cancer are often desperate to know what caused their disease. Was it something they did? Something they could have prevented?

vitanovski/Thinkstock.com

In a recent analysis, experts estimated that about 40% of cancers can be explained by known, often modifiable risk factors. Smoking and obesity represent the primary drivers, though a host of other factors – germline mutations, alcohol, infections, or environmental pollutants like asbestos – contribute to cancer risk as well.

But what about the remaining 60% of cancers?

The study suggests that, although many of these cases likely have an underlying lifestyle or environmental component, experts still do not fully understand their origin story. And a small but significant number may simply be caused by chance.

Here’s what experts suspect those missing causes might be, and why they can be so difficult to confirm.
 

Possibility 1: Known risk factors contribute more than we realize

For certain factors, a straight line can be drawn to cancer.

Take smoking, for instance. Decades of research have helped scientists clearly delineate tobacco’s carcinogenic effects. Researchers have pinpointed a unique set of mutations in the tumors of smokers that can be seen when cells grown in a dish are exposed to the carcinogens present in tobacco.

In addition, experts have been able to collect robust data from epidemiologic studies on smoking prevalence as well as associated cancer risks and deaths, in large part because an individual’s lifetime tobacco exposure is fairly easy to measure.

“The evidence for smoking is incredibly consistent,” Paul Brennan, PhD, a cancer epidemiologist at the World Health Organization’s International Agency for Research on Cancer, said in an interview.

For other known risk factors, such as obesity and air pollution, many more questions than answers remain.

Because of the limitations in how such factors are measured, we are likely downplaying their effects, said Richard Martin, PhD, a professor of clinical epidemiology at the University of Bristol (England).

Take obesity. Excess body weight is associated with an increased risk of at least 13 cancers. Although risk estimates vary by study and cancer type, according to a global snapshot from 2012, being overweight or obese accounted for about 4% of all cancers worldwide – 1% in low-income countries and as high as 8% in high-income countries.

However, Dr. Brennan believes “we have underestimated the effect of obesity [on cancer].”

A key reason, he said, is most studies use body mass index to determine whether someone is overweight or obese, but BMI is a poor measure of body fat. BMI does not differentiate between fat and muscle, which means two people with the same height and weight can have the same BMI, even if one is an athlete who eats lean meats and vegetables while the other lives a sedentary life and consumes large quantities of processed foods and alcohol.

On top of that, studies often only calculate a person’s BMI once, and a single measurement can’t tell you how a person’s weight has fluctuated in recent years or across different stages of their life. However, recent analyses suggest that obesity status over time may be more relevant to cancer risk than one-off measures.

In addition, many studies now suggest that alterations to our gut microbes and high blood insulin level – often seen in people who are overweight or obese – may increase the risk of cancer and speed the growth of tumors.

When these additional factors are considered, the impact of excess body fat may ultimately play a much more significant role in cancer risk. In fact, according to Dr. Brennan, “if we estimate [the effects of obesity] properly, it might at some point become the main cause of cancer.”
 

Possibility 2: Environmental or lifestyle factors remain under the radar

Researchers have linked many substances we consume or are exposed to in our daily lives – air pollution, toxins from industrial waste, and highly processed foods – to cancer. But the extent or contribution of potential carcinogens in our surroundings, particularly those found almost everywhere at low levels, is still largely unknown.

One simple reason is the effects of many of these substances remain difficult to assess. For instance, it is much harder to study the impact of pollutants found in food or water, in which a given population will share similar exposure levels versus tobacco, where it is possible to compare a person who smokes a pack of cigarettes a day with a person who does not smoke.

“If you’ve got exposures that are ubiquitous, it can be difficult to discern their [individual] roles,” Dr. Martin said. “There are many causes that we [likely] don’t really know because everyone has been exposed.”

On the flip side, some carcinogenic substances that people encounter for limited periods might be missed if studies are not performed at the time of exposure.

“What’s in the body at age 40 may not reflect what you were exposed at age 5-10 on the playground or soccer field,” said Graham Colditz, MD, PhD, an epidemiologist and public health expert at Washington University, St. Louis. “The technology keeps changing so we can get better measures of what you’ve got exposure to today, but how that relates to 5, 10, 15 years ago is probably very variable.”

In addition, researchers have found that many carcinogens do not cause specific mutations in a cell’s DNA; rather, studies suggest that most carcinogens lead to cancer-promoting changes in cells, such as inflammation.

“We need to think of how potential carcinogens are causing cancer,” Dr. Brennan said. Instead of provoking mutations, potential carcinogens may use a “whole other kind of pathway.” When, for instance, inflammation becomes chronic, it may spur a cascade of events that ultimately leads to cancer.

Finally, not much is known about what causes cancers in low- and middle-income countries. Most of the research to date has been in high-income countries, such the United States, Australia, and parts of Europe.

“There’s a real lack of robust epidemiological studies in other parts of the world, Latin America, Africa, parts of Asia,” Marc Gunter, PhD, a molecular epidemiologist at the IARC, told this news organization.
 

Possibility 3: Some cancers occur by chance

When it comes to cancer risk, an element of chance may be at play. Cancer can occur in individuals who have very little exposure to known carcinogens or have no family history of cancer.

“We all know there are people who get cancer who eat very healthy diets, are never overweight, and never smoke,” Dr. Gunter said. “Then there are people on the other end of the extreme who don’t get cancer.”

But what fraction of cancers are attributable to chance?

A controversial 2017 study published in Science suggested that, based on the rate of cell turnover in healthy tissues in the lung, pancreas, and other parts of the body, only about one-third of cancers could be linked to environmental or genetic factors. The rest, the authors claimed, occurred because of random mutations that accumulated in a person’s DNA – in other words, bad luck.

That study brought on a flood of criticism from scientists who pointed to serious flaws in the work that led the researchers to significantly overestimate the share of chance-related cancers.

The actual proportion of cancers that occur by chance is much lower, according to Dr. Brennan. “If you look at international comparisons [of cancer rates] and take a conservative estimate, you see that maybe 10% or 15% of cancers are really chance.”

Whether some cancers are caused by bad luck or undiscovered risk factors remains an open question.

But the bottom line is many unknown causes of cancer are likely environmental or lifestyle related, which means that, in theory, they can be altered, even prevented.

“There is always going to be some element of chance, but you can modify your chance, depending on your lifestyle and maybe other factors, which we don’t fully understand yet,” Dr. Gunter said.

The good news is that, when it comes to prevention, there are many ways to modify our behaviors – such as consuming fewer processed meats, going for a daily walk, or getting vaccinated against cancer-causing viruses – to improve our chances of living cancer free. And as scientists better understand more about what causes cancer, possibilities for prevention will only grow.

“There is a constant, slow growth [in knowledge] that is lowering the overall risk of cancer,” Dr. Brennan said. “We’re never going to eliminate cancer, but we will be able to control it as a disease.”

A version of this article first appeared on Medscape.com.

People with cancer are often desperate to know what caused their disease. Was it something they did? Something they could have prevented?

vitanovski/Thinkstock.com

In a recent analysis, experts estimated that about 40% of cancers can be explained by known, often modifiable risk factors. Smoking and obesity represent the primary drivers, though a host of other factors – germline mutations, alcohol, infections, or environmental pollutants like asbestos – contribute to cancer risk as well.

But what about the remaining 60% of cancers?

The study suggests that, although many of these cases likely have an underlying lifestyle or environmental component, experts still do not fully understand their origin story. And a small but significant number may simply be caused by chance.

Here’s what experts suspect those missing causes might be, and why they can be so difficult to confirm.
 

Possibility 1: Known risk factors contribute more than we realize

For certain factors, a straight line can be drawn to cancer.

Take smoking, for instance. Decades of research have helped scientists clearly delineate tobacco’s carcinogenic effects. Researchers have pinpointed a unique set of mutations in the tumors of smokers that can be seen when cells grown in a dish are exposed to the carcinogens present in tobacco.

In addition, experts have been able to collect robust data from epidemiologic studies on smoking prevalence as well as associated cancer risks and deaths, in large part because an individual’s lifetime tobacco exposure is fairly easy to measure.

“The evidence for smoking is incredibly consistent,” Paul Brennan, PhD, a cancer epidemiologist at the World Health Organization’s International Agency for Research on Cancer, said in an interview.

For other known risk factors, such as obesity and air pollution, many more questions than answers remain.

Because of the limitations in how such factors are measured, we are likely downplaying their effects, said Richard Martin, PhD, a professor of clinical epidemiology at the University of Bristol (England).

Take obesity. Excess body weight is associated with an increased risk of at least 13 cancers. Although risk estimates vary by study and cancer type, according to a global snapshot from 2012, being overweight or obese accounted for about 4% of all cancers worldwide – 1% in low-income countries and as high as 8% in high-income countries.

However, Dr. Brennan believes “we have underestimated the effect of obesity [on cancer].”

A key reason, he said, is most studies use body mass index to determine whether someone is overweight or obese, but BMI is a poor measure of body fat. BMI does not differentiate between fat and muscle, which means two people with the same height and weight can have the same BMI, even if one is an athlete who eats lean meats and vegetables while the other lives a sedentary life and consumes large quantities of processed foods and alcohol.

On top of that, studies often only calculate a person’s BMI once, and a single measurement can’t tell you how a person’s weight has fluctuated in recent years or across different stages of their life. However, recent analyses suggest that obesity status over time may be more relevant to cancer risk than one-off measures.

In addition, many studies now suggest that alterations to our gut microbes and high blood insulin level – often seen in people who are overweight or obese – may increase the risk of cancer and speed the growth of tumors.

When these additional factors are considered, the impact of excess body fat may ultimately play a much more significant role in cancer risk. In fact, according to Dr. Brennan, “if we estimate [the effects of obesity] properly, it might at some point become the main cause of cancer.”
 

Possibility 2: Environmental or lifestyle factors remain under the radar

Researchers have linked many substances we consume or are exposed to in our daily lives – air pollution, toxins from industrial waste, and highly processed foods – to cancer. But the extent or contribution of potential carcinogens in our surroundings, particularly those found almost everywhere at low levels, is still largely unknown.

One simple reason is the effects of many of these substances remain difficult to assess. For instance, it is much harder to study the impact of pollutants found in food or water, in which a given population will share similar exposure levels versus tobacco, where it is possible to compare a person who smokes a pack of cigarettes a day with a person who does not smoke.

“If you’ve got exposures that are ubiquitous, it can be difficult to discern their [individual] roles,” Dr. Martin said. “There are many causes that we [likely] don’t really know because everyone has been exposed.”

On the flip side, some carcinogenic substances that people encounter for limited periods might be missed if studies are not performed at the time of exposure.

“What’s in the body at age 40 may not reflect what you were exposed at age 5-10 on the playground or soccer field,” said Graham Colditz, MD, PhD, an epidemiologist and public health expert at Washington University, St. Louis. “The technology keeps changing so we can get better measures of what you’ve got exposure to today, but how that relates to 5, 10, 15 years ago is probably very variable.”

In addition, researchers have found that many carcinogens do not cause specific mutations in a cell’s DNA; rather, studies suggest that most carcinogens lead to cancer-promoting changes in cells, such as inflammation.

“We need to think of how potential carcinogens are causing cancer,” Dr. Brennan said. Instead of provoking mutations, potential carcinogens may use a “whole other kind of pathway.” When, for instance, inflammation becomes chronic, it may spur a cascade of events that ultimately leads to cancer.

Finally, not much is known about what causes cancers in low- and middle-income countries. Most of the research to date has been in high-income countries, such the United States, Australia, and parts of Europe.

“There’s a real lack of robust epidemiological studies in other parts of the world, Latin America, Africa, parts of Asia,” Marc Gunter, PhD, a molecular epidemiologist at the IARC, told this news organization.
 

Possibility 3: Some cancers occur by chance

When it comes to cancer risk, an element of chance may be at play. Cancer can occur in individuals who have very little exposure to known carcinogens or have no family history of cancer.

“We all know there are people who get cancer who eat very healthy diets, are never overweight, and never smoke,” Dr. Gunter said. “Then there are people on the other end of the extreme who don’t get cancer.”

But what fraction of cancers are attributable to chance?

A controversial 2017 study published in Science suggested that, based on the rate of cell turnover in healthy tissues in the lung, pancreas, and other parts of the body, only about one-third of cancers could be linked to environmental or genetic factors. The rest, the authors claimed, occurred because of random mutations that accumulated in a person’s DNA – in other words, bad luck.

That study brought on a flood of criticism from scientists who pointed to serious flaws in the work that led the researchers to significantly overestimate the share of chance-related cancers.

The actual proportion of cancers that occur by chance is much lower, according to Dr. Brennan. “If you look at international comparisons [of cancer rates] and take a conservative estimate, you see that maybe 10% or 15% of cancers are really chance.”

Whether some cancers are caused by bad luck or undiscovered risk factors remains an open question.

But the bottom line is many unknown causes of cancer are likely environmental or lifestyle related, which means that, in theory, they can be altered, even prevented.

“There is always going to be some element of chance, but you can modify your chance, depending on your lifestyle and maybe other factors, which we don’t fully understand yet,” Dr. Gunter said.

The good news is that, when it comes to prevention, there are many ways to modify our behaviors – such as consuming fewer processed meats, going for a daily walk, or getting vaccinated against cancer-causing viruses – to improve our chances of living cancer free. And as scientists better understand more about what causes cancer, possibilities for prevention will only grow.

“There is a constant, slow growth [in knowledge] that is lowering the overall risk of cancer,” Dr. Brennan said. “We’re never going to eliminate cancer, but we will be able to control it as a disease.”

A version of this article first appeared on Medscape.com.

The International Skin Imaging Collaboration (ISIC) Artificial Intelligence Working Group has released the first-ever guidelines for developing artificial intelligence (AI) algorithms used in dermatology.

Christopher Smith

The guidelines, published in JAMA Dermatology on Dec. 1, 2021, contain a broad range of recommendations stakeholders should consider when developing and assessing image-based AI algorithms in dermatology. The recommendations are divided into categories of data, technique, technical assessment, and application. ISIC is “an academia and industry partnership designed to facilitate the application of digital skin imaging to help reduce melanoma mortality,” and is organized into different working groups, including the AI working group, according to its website.

“Our goal with these guidelines was to create higher-quality reporting of dataset and algorithm characteristics for dermatology AI,” first author Roxana Daneshjou, MD, PhD, clinical scholar in dermatology, in the department of dermatology at Stanford (Calif.) University, said in an interview. “We hope these guidelines also aid regulatory bodies around the world when they are assessing algorithms to be used in dermatology.”
 

Recommendations for data

The authors recommended that datasets used by AI algorithms have image descriptions and details on image artifacts. “For photography, these include the type of camera used; whether images were taken under standardized or varying conditions; whether they were taken by professional photographers, laymen, or health care professionals; and image quality,” they wrote. They also recommended that developers include in an image description the type of lighting used and whether the photo contains pen markings, hair, tattoos, injuries, surgical effects, or other “physical perturbations.”

Exchangeable image file format data obtained from the camera, and preprocessing procedures like color normalization and “postprocessing” of images, such as filtering, should also be disclosed. In addition, developers should disclose and justify inclusion of images that have been created by an algorithm within a dataset. Any public images used in the datasets should have references, and privately used images should be made public where possible, the authors said.

The ISIC working group guidelines also provided recommendations for patient-level metadata. Each image should include a patient’s geographical location and medical center they visited as well as their age, sex and gender, ethnicity and/or race, and skin tone. Dr. Daneshjou said this was one area where she and her colleagues found a lack of transparency in AI datasets in algorithms in a recent review. “We found that many AI papers provided sparse details about the images used to train and test their algorithms,” Dr. Daneshjou explained. “For example, only 7 out of 70 papers had any information about the skin tones in the images used for developing and/or testing AI algorithms. Understanding the diversity of images used to train and test algorithms is important because algorithms that are developed on images of predominantly white skin likely won’t work as well on Black and brown skin.”

The guideline authors also asked algorithm developers to describe the limitations of not including patient-level metadata information when it is incomplete or unavailable. In addition, “we ask that algorithm developers comment on potential biases of their algorithms,” Dr. Daneshjou said. “For example, an algorithm based only on telemedicine images may not capture the full range of diseases seen within an in-person clinic.”

When describing their AI algorithm, developers should detail their reasoning for the dataset size and partitions, inclusion and exclusion criteria for images, and use of any external samples for test sets. “Authors should consider any differences between the image characteristics used for algorithm development and those that might be encountered in the real world,” the guidelines stated.

Recommendations for technique

How the images in a dataset are labeled is a unique challenge in developing AI algorithms for dermatology, the authors noted. Developers should use histopathological diagnosis in their labeling, but this can sometimes result in label noise.

“Many of the AI algorithms in dermatology use supervised learning, which requires labeled examples to help the algorithm ‘learn’ features for discriminating between lesions. We found that some papers use consensus labeling – dermatologists providing a label – to label skin cancers; however, the standard for diagnosing skin cancer is using histopathology from a biopsy,” she said. “Dermatologists can biopsy seven to eight suspected melanomas before discovering a true melanoma, so dermatologist labeling of skin cancers is prone to label noise.”

ISIC’s guidelines stated a gold standard of labeling for dermatologic images is one area that still needs future research, but currently, “diagnoses, labels and diagnostic groups used in data repositories as well as public ontologies” such as ICD-11, AnatomyMapper, and SNOMED-CT should be included in dermatologic image datasets.

AI developers should also provide a detailed description of their algorithm, which includes methods, work flows, mathematical formulas as well as the generalizability of the algorithm across more than one dataset.
 

Recommendations for technical assessment

“Another important recommendation is that algorithm developers should provide a way for algorithms to be publicly evaluable by researchers,” Dr. Daneshjou said. “Many dermatology AI algorithms do not share either their data or their algorithm. Algorithm sharing is important for assessing reproducibility and robustness.”

Google’s recently announced AI-powered dermatology assistant tool, for example, “has made claims about its accuracy and ability to diagnose skin disease at a dermatologist level, but there is no way for researchers to independently test these claims,” she said. Other options like Model Dermatology, developed by Seung Seog Han, MD, PhD, of the Dermatology Clinic in Seoul, South Korea, and colleagues, offer an application programming interface “that allows researchers to test the algorithm,” Dr. Daneshjou said. “This kind of openness is key for assessing algorithm robustness.”

Developers should also note in their algorithm explanations how performance markers and benchmarks would translate to proposed clinical application. “In this context,” the use case – the context in which the AI application is being used – “should be clearly described – who are the intended users and under what clinical scenario are they using the algorithm,” the authors wrote.
 

Recommendations for application

The guidelines note that use case for the model should also be described by the AI developers. “Our checklist includes delineating use cases for algorithms and describing what use cases may be within the scope of the algorithm versus which use cases are out of scope,” Dr. Daneshjou said. “For example, an algorithm developed to provide decision support to dermatologists, with a human in the loop, may not be accurate enough to release directly to consumers.”

As the goal of AI algorithms in dermatology is eventual implementation for clinicians and patients, the authors asked developers to consider shortcomings and potential harms of the algorithm during implementation. “Ethical considerations and impact on vulnerable populations should also be considered and discussed,” they wrote. An algorithm “suggesting aesthetic medical treatments may have negative effects given the biased nature of beauty standards,” and “an algorithm that diagnoses basal cell carcinomas but lacks any pigmented basal cell carcinomas, which are more often seen in skin of color, will not perform equitably across populations.”

Prior to implementing an AI algorithm, the ISIC working group recommended developers perform prospective clinical trials for validation. Checklists and guidelines like SPIRIT-AI and CONSORT-AI “provide guidance on how to design clinical trials to test AI algorithms,” Dr. Daneshjou said.

After implementation, “I believe we need additional research in how we monitor algorithms after they are deployed clinically, Dr. Daneshjou said. “Currently there are no [Food and Drug Administration]–approved AI algorithms in dermatology; however, there are several applications that have CE mark in Europe, and there are no mechanisms for postmarket surveillance there.
 

'Timely' recommendations

Commenting on the ISIC working group guidelines, Justin M. Ko, MD, MBA, director and chief of medical dermatology for Stanford Health Care, who was not involved with the work, said that the recommendations are timely and provide “a framework for a ‘common language’ around AI datasets specifically tailored to dermatology.” Dr. Ko, chair of the American Academy of Dermatology’s Ad Hoc Task Force on Augmented Intelligence, noted the work by Dr. Daneshjou and colleagues “is consistent with and builds further details” on the position statement released by the AAD AI task force in 2019.

“As machine-learning capabilities and commercial efforts continue to mature, it becomes increasingly important that we are able to ‘look under the hood,’ and evaluate all the critical factors that influence development of these capabilities,” he said in an interview. “A standard set of reporting guidelines not only allows for transparency in evaluating data and performance of models and algorithms, but also forces the consideration of issues of equity, fairness, mitigation of bias, and clinically meaningful outcomes.”

One concern is the impact of AI algorithms on societal or health systems, he noted, which is brought up in the guidelines. “The last thing we would want is the development of robust AI systems that exacerbate access challenges, or generate patient anxiety/worry, or drive low-value utilization, or adds to care team burden, or create a technological barrier to care, or increases inequity in dermatologic care,” he said.

In developing AI algorithms for dermatology, a “major practical issue” is how performance on paper will translate to real-world use, Dr. Ko explained, and the ISIC guidelines “provide a critical step in empowering clinicians, practices, and our field to shape the advent of the AI and augmented intelligence tools and systems to promote and enhance meaningful clinical outcomes, and augment the core patient-clinician relationship and ensure they are grounded in principles of fairness, equity and transparency.”

This research was funded by awards and grants to individual authors from the Charina Fund, a Google Research Award, Melanoma Research Alliance, National Health and Medical Research Council, National Institutes of Health/National Cancer Institute, National Science Foundation, and the Department of Veterans Affairs. The authors disclosed relationships with governmental entities, pharmaceutical companies, technology startups, medical publishers, charitable trusts, consulting firms, dermatology training companies, providers of medical devices, manufacturers of dermatologic products, and other organizations related to the paper in the form of supplied equipment, having founded a company; receiving grants, patents, or personal fees; holding shares; and medical reporting. Dr. Ko reported that he serves as a clinical advisor for Skin Analytics, and has an ongoing research collaboration with Google.

The International Skin Imaging Collaboration (ISIC) Artificial Intelligence Working Group has released the first-ever guidelines for developing artificial intelligence (AI) algorithms used in dermatology.

Christopher Smith

The guidelines, published in JAMA Dermatology on Dec. 1, 2021, contain a broad range of recommendations stakeholders should consider when developing and assessing image-based AI algorithms in dermatology. The recommendations are divided into categories of data, technique, technical assessment, and application. ISIC is “an academia and industry partnership designed to facilitate the application of digital skin imaging to help reduce melanoma mortality,” and is organized into different working groups, including the AI working group, according to its website.

“Our goal with these guidelines was to create higher-quality reporting of dataset and algorithm characteristics for dermatology AI,” first author Roxana Daneshjou, MD, PhD, clinical scholar in dermatology, in the department of dermatology at Stanford (Calif.) University, said in an interview. “We hope these guidelines also aid regulatory bodies around the world when they are assessing algorithms to be used in dermatology.”
 

Recommendations for data

The authors recommended that datasets used by AI algorithms have image descriptions and details on image artifacts. “For photography, these include the type of camera used; whether images were taken under standardized or varying conditions; whether they were taken by professional photographers, laymen, or health care professionals; and image quality,” they wrote. They also recommended that developers include in an image description the type of lighting used and whether the photo contains pen markings, hair, tattoos, injuries, surgical effects, or other “physical perturbations.”

Exchangeable image file format data obtained from the camera, and preprocessing procedures like color normalization and “postprocessing” of images, such as filtering, should also be disclosed. In addition, developers should disclose and justify inclusion of images that have been created by an algorithm within a dataset. Any public images used in the datasets should have references, and privately used images should be made public where possible, the authors said.

The ISIC working group guidelines also provided recommendations for patient-level metadata. Each image should include a patient’s geographical location and medical center they visited as well as their age, sex and gender, ethnicity and/or race, and skin tone. Dr. Daneshjou said this was one area where she and her colleagues found a lack of transparency in AI datasets in algorithms in a recent review. “We found that many AI papers provided sparse details about the images used to train and test their algorithms,” Dr. Daneshjou explained. “For example, only 7 out of 70 papers had any information about the skin tones in the images used for developing and/or testing AI algorithms. Understanding the diversity of images used to train and test algorithms is important because algorithms that are developed on images of predominantly white skin likely won’t work as well on Black and brown skin.”

The guideline authors also asked algorithm developers to describe the limitations of not including patient-level metadata information when it is incomplete or unavailable. In addition, “we ask that algorithm developers comment on potential biases of their algorithms,” Dr. Daneshjou said. “For example, an algorithm based only on telemedicine images may not capture the full range of diseases seen within an in-person clinic.”

When describing their AI algorithm, developers should detail their reasoning for the dataset size and partitions, inclusion and exclusion criteria for images, and use of any external samples for test sets. “Authors should consider any differences between the image characteristics used for algorithm development and those that might be encountered in the real world,” the guidelines stated.

Recommendations for technique

How the images in a dataset are labeled is a unique challenge in developing AI algorithms for dermatology, the authors noted. Developers should use histopathological diagnosis in their labeling, but this can sometimes result in label noise.

“Many of the AI algorithms in dermatology use supervised learning, which requires labeled examples to help the algorithm ‘learn’ features for discriminating between lesions. We found that some papers use consensus labeling – dermatologists providing a label – to label skin cancers; however, the standard for diagnosing skin cancer is using histopathology from a biopsy,” she said. “Dermatologists can biopsy seven to eight suspected melanomas before discovering a true melanoma, so dermatologist labeling of skin cancers is prone to label noise.”

ISIC’s guidelines stated a gold standard of labeling for dermatologic images is one area that still needs future research, but currently, “diagnoses, labels and diagnostic groups used in data repositories as well as public ontologies” such as ICD-11, AnatomyMapper, and SNOMED-CT should be included in dermatologic image datasets.

AI developers should also provide a detailed description of their algorithm, which includes methods, work flows, mathematical formulas as well as the generalizability of the algorithm across more than one dataset.
 

Recommendations for technical assessment

“Another important recommendation is that algorithm developers should provide a way for algorithms to be publicly evaluable by researchers,” Dr. Daneshjou said. “Many dermatology AI algorithms do not share either their data or their algorithm. Algorithm sharing is important for assessing reproducibility and robustness.”

Google’s recently announced AI-powered dermatology assistant tool, for example, “has made claims about its accuracy and ability to diagnose skin disease at a dermatologist level, but there is no way for researchers to independently test these claims,” she said. Other options like Model Dermatology, developed by Seung Seog Han, MD, PhD, of the Dermatology Clinic in Seoul, South Korea, and colleagues, offer an application programming interface “that allows researchers to test the algorithm,” Dr. Daneshjou said. “This kind of openness is key for assessing algorithm robustness.”

Developers should also note in their algorithm explanations how performance markers and benchmarks would translate to proposed clinical application. “In this context,” the use case – the context in which the AI application is being used – “should be clearly described – who are the intended users and under what clinical scenario are they using the algorithm,” the authors wrote.
 

Recommendations for application

The guidelines note that use case for the model should also be described by the AI developers. “Our checklist includes delineating use cases for algorithms and describing what use cases may be within the scope of the algorithm versus which use cases are out of scope,” Dr. Daneshjou said. “For example, an algorithm developed to provide decision support to dermatologists, with a human in the loop, may not be accurate enough to release directly to consumers.”

As the goal of AI algorithms in dermatology is eventual implementation for clinicians and patients, the authors asked developers to consider shortcomings and potential harms of the algorithm during implementation. “Ethical considerations and impact on vulnerable populations should also be considered and discussed,” they wrote. An algorithm “suggesting aesthetic medical treatments may have negative effects given the biased nature of beauty standards,” and “an algorithm that diagnoses basal cell carcinomas but lacks any pigmented basal cell carcinomas, which are more often seen in skin of color, will not perform equitably across populations.”

Prior to implementing an AI algorithm, the ISIC working group recommended developers perform prospective clinical trials for validation. Checklists and guidelines like SPIRIT-AI and CONSORT-AI “provide guidance on how to design clinical trials to test AI algorithms,” Dr. Daneshjou said.

After implementation, “I believe we need additional research in how we monitor algorithms after they are deployed clinically, Dr. Daneshjou said. “Currently there are no [Food and Drug Administration]–approved AI algorithms in dermatology; however, there are several applications that have CE mark in Europe, and there are no mechanisms for postmarket surveillance there.
 

'Timely' recommendations

Commenting on the ISIC working group guidelines, Justin M. Ko, MD, MBA, director and chief of medical dermatology for Stanford Health Care, who was not involved with the work, said that the recommendations are timely and provide “a framework for a ‘common language’ around AI datasets specifically tailored to dermatology.” Dr. Ko, chair of the American Academy of Dermatology’s Ad Hoc Task Force on Augmented Intelligence, noted the work by Dr. Daneshjou and colleagues “is consistent with and builds further details” on the position statement released by the AAD AI task force in 2019.

“As machine-learning capabilities and commercial efforts continue to mature, it becomes increasingly important that we are able to ‘look under the hood,’ and evaluate all the critical factors that influence development of these capabilities,” he said in an interview. “A standard set of reporting guidelines not only allows for transparency in evaluating data and performance of models and algorithms, but also forces the consideration of issues of equity, fairness, mitigation of bias, and clinically meaningful outcomes.”

One concern is the impact of AI algorithms on societal or health systems, he noted, which is brought up in the guidelines. “The last thing we would want is the development of robust AI systems that exacerbate access challenges, or generate patient anxiety/worry, or drive low-value utilization, or adds to care team burden, or create a technological barrier to care, or increases inequity in dermatologic care,” he said.

In developing AI algorithms for dermatology, a “major practical issue” is how performance on paper will translate to real-world use, Dr. Ko explained, and the ISIC guidelines “provide a critical step in empowering clinicians, practices, and our field to shape the advent of the AI and augmented intelligence tools and systems to promote and enhance meaningful clinical outcomes, and augment the core patient-clinician relationship and ensure they are grounded in principles of fairness, equity and transparency.”

This research was funded by awards and grants to individual authors from the Charina Fund, a Google Research Award, Melanoma Research Alliance, National Health and Medical Research Council, National Institutes of Health/National Cancer Institute, National Science Foundation, and the Department of Veterans Affairs. The authors disclosed relationships with governmental entities, pharmaceutical companies, technology startups, medical publishers, charitable trusts, consulting firms, dermatology training companies, providers of medical devices, manufacturers of dermatologic products, and other organizations related to the paper in the form of supplied equipment, having founded a company; receiving grants, patents, or personal fees; holding shares; and medical reporting. Dr. Ko reported that he serves as a clinical advisor for Skin Analytics, and has an ongoing research collaboration with Google.

The International Skin Imaging Collaboration (ISIC) Artificial Intelligence Working Group has released the first-ever guidelines for developing artificial intelligence (AI) algorithms used in dermatology.

Christopher Smith

The guidelines, published in JAMA Dermatology on Dec. 1, 2021, contain a broad range of recommendations stakeholders should consider when developing and assessing image-based AI algorithms in dermatology. The recommendations are divided into categories of data, technique, technical assessment, and application. ISIC is “an academia and industry partnership designed to facilitate the application of digital skin imaging to help reduce melanoma mortality,” and is organized into different working groups, including the AI working group, according to its website.

“Our goal with these guidelines was to create higher-quality reporting of dataset and algorithm characteristics for dermatology AI,” first author Roxana Daneshjou, MD, PhD, clinical scholar in dermatology, in the department of dermatology at Stanford (Calif.) University, said in an interview. “We hope these guidelines also aid regulatory bodies around the world when they are assessing algorithms to be used in dermatology.”
 

Recommendations for data

The authors recommended that datasets used by AI algorithms have image descriptions and details on image artifacts. “For photography, these include the type of camera used; whether images were taken under standardized or varying conditions; whether they were taken by professional photographers, laymen, or health care professionals; and image quality,” they wrote. They also recommended that developers include in an image description the type of lighting used and whether the photo contains pen markings, hair, tattoos, injuries, surgical effects, or other “physical perturbations.”

Exchangeable image file format data obtained from the camera, and preprocessing procedures like color normalization and “postprocessing” of images, such as filtering, should also be disclosed. In addition, developers should disclose and justify inclusion of images that have been created by an algorithm within a dataset. Any public images used in the datasets should have references, and privately used images should be made public where possible, the authors said.

The ISIC working group guidelines also provided recommendations for patient-level metadata. Each image should include a patient’s geographical location and medical center they visited as well as their age, sex and gender, ethnicity and/or race, and skin tone. Dr. Daneshjou said this was one area where she and her colleagues found a lack of transparency in AI datasets in algorithms in a recent review. “We found that many AI papers provided sparse details about the images used to train and test their algorithms,” Dr. Daneshjou explained. “For example, only 7 out of 70 papers had any information about the skin tones in the images used for developing and/or testing AI algorithms. Understanding the diversity of images used to train and test algorithms is important because algorithms that are developed on images of predominantly white skin likely won’t work as well on Black and brown skin.”

The guideline authors also asked algorithm developers to describe the limitations of not including patient-level metadata information when it is incomplete or unavailable. In addition, “we ask that algorithm developers comment on potential biases of their algorithms,” Dr. Daneshjou said. “For example, an algorithm based only on telemedicine images may not capture the full range of diseases seen within an in-person clinic.”

When describing their AI algorithm, developers should detail their reasoning for the dataset size and partitions, inclusion and exclusion criteria for images, and use of any external samples for test sets. “Authors should consider any differences between the image characteristics used for algorithm development and those that might be encountered in the real world,” the guidelines stated.

Recommendations for technique

How the images in a dataset are labeled is a unique challenge in developing AI algorithms for dermatology, the authors noted. Developers should use histopathological diagnosis in their labeling, but this can sometimes result in label noise.

“Many of the AI algorithms in dermatology use supervised learning, which requires labeled examples to help the algorithm ‘learn’ features for discriminating between lesions. We found that some papers use consensus labeling – dermatologists providing a label – to label skin cancers; however, the standard for diagnosing skin cancer is using histopathology from a biopsy,” she said. “Dermatologists can biopsy seven to eight suspected melanomas before discovering a true melanoma, so dermatologist labeling of skin cancers is prone to label noise.”

ISIC’s guidelines stated a gold standard of labeling for dermatologic images is one area that still needs future research, but currently, “diagnoses, labels and diagnostic groups used in data repositories as well as public ontologies” such as ICD-11, AnatomyMapper, and SNOMED-CT should be included in dermatologic image datasets.

AI developers should also provide a detailed description of their algorithm, which includes methods, work flows, mathematical formulas as well as the generalizability of the algorithm across more than one dataset.
 

Recommendations for technical assessment

“Another important recommendation is that algorithm developers should provide a way for algorithms to be publicly evaluable by researchers,” Dr. Daneshjou said. “Many dermatology AI algorithms do not share either their data or their algorithm. Algorithm sharing is important for assessing reproducibility and robustness.”

Google’s recently announced AI-powered dermatology assistant tool, for example, “has made claims about its accuracy and ability to diagnose skin disease at a dermatologist level, but there is no way for researchers to independently test these claims,” she said. Other options like Model Dermatology, developed by Seung Seog Han, MD, PhD, of the Dermatology Clinic in Seoul, South Korea, and colleagues, offer an application programming interface “that allows researchers to test the algorithm,” Dr. Daneshjou said. “This kind of openness is key for assessing algorithm robustness.”

Developers should also note in their algorithm explanations how performance markers and benchmarks would translate to proposed clinical application. “In this context,” the use case – the context in which the AI application is being used – “should be clearly described – who are the intended users and under what clinical scenario are they using the algorithm,” the authors wrote.
 

Recommendations for application

The guidelines note that use case for the model should also be described by the AI developers. “Our checklist includes delineating use cases for algorithms and describing what use cases may be within the scope of the algorithm versus which use cases are out of scope,” Dr. Daneshjou said. “For example, an algorithm developed to provide decision support to dermatologists, with a human in the loop, may not be accurate enough to release directly to consumers.”

As the goal of AI algorithms in dermatology is eventual implementation for clinicians and patients, the authors asked developers to consider shortcomings and potential harms of the algorithm during implementation. “Ethical considerations and impact on vulnerable populations should also be considered and discussed,” they wrote. An algorithm “suggesting aesthetic medical treatments may have negative effects given the biased nature of beauty standards,” and “an algorithm that diagnoses basal cell carcinomas but lacks any pigmented basal cell carcinomas, which are more often seen in skin of color, will not perform equitably across populations.”

Prior to implementing an AI algorithm, the ISIC working group recommended developers perform prospective clinical trials for validation. Checklists and guidelines like SPIRIT-AI and CONSORT-AI “provide guidance on how to design clinical trials to test AI algorithms,” Dr. Daneshjou said.

After implementation, “I believe we need additional research in how we monitor algorithms after they are deployed clinically, Dr. Daneshjou said. “Currently there are no [Food and Drug Administration]–approved AI algorithms in dermatology; however, there are several applications that have CE mark in Europe, and there are no mechanisms for postmarket surveillance there.
 

'Timely' recommendations

Commenting on the ISIC working group guidelines, Justin M. Ko, MD, MBA, director and chief of medical dermatology for Stanford Health Care, who was not involved with the work, said that the recommendations are timely and provide “a framework for a ‘common language’ around AI datasets specifically tailored to dermatology.” Dr. Ko, chair of the American Academy of Dermatology’s Ad Hoc Task Force on Augmented Intelligence, noted the work by Dr. Daneshjou and colleagues “is consistent with and builds further details” on the position statement released by the AAD AI task force in 2019.

“As machine-learning capabilities and commercial efforts continue to mature, it becomes increasingly important that we are able to ‘look under the hood,’ and evaluate all the critical factors that influence development of these capabilities,” he said in an interview. “A standard set of reporting guidelines not only allows for transparency in evaluating data and performance of models and algorithms, but also forces the consideration of issues of equity, fairness, mitigation of bias, and clinically meaningful outcomes.”

One concern is the impact of AI algorithms on societal or health systems, he noted, which is brought up in the guidelines. “The last thing we would want is the development of robust AI systems that exacerbate access challenges, or generate patient anxiety/worry, or drive low-value utilization, or adds to care team burden, or create a technological barrier to care, or increases inequity in dermatologic care,” he said.

In developing AI algorithms for dermatology, a “major practical issue” is how performance on paper will translate to real-world use, Dr. Ko explained, and the ISIC guidelines “provide a critical step in empowering clinicians, practices, and our field to shape the advent of the AI and augmented intelligence tools and systems to promote and enhance meaningful clinical outcomes, and augment the core patient-clinician relationship and ensure they are grounded in principles of fairness, equity and transparency.”

This research was funded by awards and grants to individual authors from the Charina Fund, a Google Research Award, Melanoma Research Alliance, National Health and Medical Research Council, National Institutes of Health/National Cancer Institute, National Science Foundation, and the Department of Veterans Affairs. The authors disclosed relationships with governmental entities, pharmaceutical companies, technology startups, medical publishers, charitable trusts, consulting firms, dermatology training companies, providers of medical devices, manufacturers of dermatologic products, and other organizations related to the paper in the form of supplied equipment, having founded a company; receiving grants, patents, or personal fees; holding shares; and medical reporting. Dr. Ko reported that he serves as a clinical advisor for Skin Analytics, and has an ongoing research collaboration with Google.

There is an increased incidence of locally staged Merkel cell carcinoma (MCC) among patients who live in rural areas of the United States, compared with those in urban and metropolitan areas, yet overall survival is worse in rural areas.

This paradox was discovered in an analysis of data from the Surveillance, Epidemiology, and End Results (SEER) Program that primary author Bryan T. Carroll, MD, PhD, and colleagues presented during a virtual abstract session at the annual meeting of the American Society for Dermatologic Surgery.

“MCC is a rare and aggressive neoplasm of the skin with high mortality,” said coauthor Emma Larson, MD, a dermatology clinical research fellow at University Hospitals of Cleveland. “Previous studies have demonstrated that MCC survival is lower in low–dermatologist density areas. Associations are difficult to characterize without historical staging data aggregated from large registries. We hypothesized that decreased MCC survival is associated with rural counties.”

The researchers used 18 registries from the November 2019 SEER database to retrospectively evaluate adults who were diagnosed with MCC between 2004 and 2015 as confirmed by positive histology. Study endpoints were SEER historic stage at diagnosis and 5-year survival. MCC cases were stratified by 2013 USDA urban-rural continuum codes, which defines metropolitan counties as those with a population of 1 million or more, urban counties as those with a population of less than 1 million, and rural counties as nonmetropolitan counties not adjacent to a metropolitan area.

A total of 6,291 cases with a mean age of 75 years were included in the final analysis: 3,750 from metro areas, 2,235 from urban areas, and 306 from rural areas. A higher proportion of MCC patients from rural areas were male (69% vs. 62% from metro areas and 64% from urban areas) and white (97% vs. 95% and 96%, respectively). “This may contribute to differences in MCC care,” Dr. Larson said. “However, we also found that there is an increased incidence of locally staged disease in rural areas (51%) than in metro (44%) or urban (45%) areas (P = .02). In addition, fewer lymph node surgeries were performed in rural (50%) and urban (51%) areas than in metro areas (45%; P = .01).”

Overall survival was worse among patients in rural areas (a mean of 34 months), compared with those in urban (a mean of 41 months) and metro areas (a mean of 47 months; P = .02). “This may be due to the fact that rural counties have the higher risk factors for MCC incidence and death, but when we account for the confounders, including sex, age, race, and MCC stage, we still found a difference in overall survival in rural counties, compared to metro and urban counties,” Dr. Larson said.

Dr. Carroll, an associate professor of dermatology at University Hospitals of Cleveland, characterized the finding as “not what you’d expect with a higher incidence of local disease. Therefore, there is the potential for mis-staging in rural counties, where we did see that the interrogation of lymph nodes was done less frequently than in urban centers, which were more aligned with National Comprehensive Cancer Network guidelines during this time period. Still, after correction, rural location is still associated with a higher MCC mortality. There is a need for us to further interrogate what the causes are for this disparity in care between rural and urban centers.”

The other study authors were Dustin DeMeo and Christian Scheufele, MD. The researchers reported having no relevant financial disclosures.

[email protected]

There is an increased incidence of locally staged Merkel cell carcinoma (MCC) among patients who live in rural areas of the United States, compared with those in urban and metropolitan areas, yet overall survival is worse in rural areas.

This paradox was discovered in an analysis of data from the Surveillance, Epidemiology, and End Results (SEER) Program that primary author Bryan T. Carroll, MD, PhD, and colleagues presented during a virtual abstract session at the annual meeting of the American Society for Dermatologic Surgery.

“MCC is a rare and aggressive neoplasm of the skin with high mortality,” said coauthor Emma Larson, MD, a dermatology clinical research fellow at University Hospitals of Cleveland. “Previous studies have demonstrated that MCC survival is lower in low–dermatologist density areas. Associations are difficult to characterize without historical staging data aggregated from large registries. We hypothesized that decreased MCC survival is associated with rural counties.”

The researchers used 18 registries from the November 2019 SEER database to retrospectively evaluate adults who were diagnosed with MCC between 2004 and 2015 as confirmed by positive histology. Study endpoints were SEER historic stage at diagnosis and 5-year survival. MCC cases were stratified by 2013 USDA urban-rural continuum codes, which defines metropolitan counties as those with a population of 1 million or more, urban counties as those with a population of less than 1 million, and rural counties as nonmetropolitan counties not adjacent to a metropolitan area.

A total of 6,291 cases with a mean age of 75 years were included in the final analysis: 3,750 from metro areas, 2,235 from urban areas, and 306 from rural areas. A higher proportion of MCC patients from rural areas were male (69% vs. 62% from metro areas and 64% from urban areas) and white (97% vs. 95% and 96%, respectively). “This may contribute to differences in MCC care,” Dr. Larson said. “However, we also found that there is an increased incidence of locally staged disease in rural areas (51%) than in metro (44%) or urban (45%) areas (P = .02). In addition, fewer lymph node surgeries were performed in rural (50%) and urban (51%) areas than in metro areas (45%; P = .01).”

Overall survival was worse among patients in rural areas (a mean of 34 months), compared with those in urban (a mean of 41 months) and metro areas (a mean of 47 months; P = .02). “This may be due to the fact that rural counties have the higher risk factors for MCC incidence and death, but when we account for the confounders, including sex, age, race, and MCC stage, we still found a difference in overall survival in rural counties, compared to metro and urban counties,” Dr. Larson said.

Dr. Carroll, an associate professor of dermatology at University Hospitals of Cleveland, characterized the finding as “not what you’d expect with a higher incidence of local disease. Therefore, there is the potential for mis-staging in rural counties, where we did see that the interrogation of lymph nodes was done less frequently than in urban centers, which were more aligned with National Comprehensive Cancer Network guidelines during this time period. Still, after correction, rural location is still associated with a higher MCC mortality. There is a need for us to further interrogate what the causes are for this disparity in care between rural and urban centers.”

The other study authors were Dustin DeMeo and Christian Scheufele, MD. The researchers reported having no relevant financial disclosures.

[email protected]

There is an increased incidence of locally staged Merkel cell carcinoma (MCC) among patients who live in rural areas of the United States, compared with those in urban and metropolitan areas, yet overall survival is worse in rural areas.

This paradox was discovered in an analysis of data from the Surveillance, Epidemiology, and End Results (SEER) Program that primary author Bryan T. Carroll, MD, PhD, and colleagues presented during a virtual abstract session at the annual meeting of the American Society for Dermatologic Surgery.

“MCC is a rare and aggressive neoplasm of the skin with high mortality,” said coauthor Emma Larson, MD, a dermatology clinical research fellow at University Hospitals of Cleveland. “Previous studies have demonstrated that MCC survival is lower in low–dermatologist density areas. Associations are difficult to characterize without historical staging data aggregated from large registries. We hypothesized that decreased MCC survival is associated with rural counties.”

The researchers used 18 registries from the November 2019 SEER database to retrospectively evaluate adults who were diagnosed with MCC between 2004 and 2015 as confirmed by positive histology. Study endpoints were SEER historic stage at diagnosis and 5-year survival. MCC cases were stratified by 2013 USDA urban-rural continuum codes, which defines metropolitan counties as those with a population of 1 million or more, urban counties as those with a population of less than 1 million, and rural counties as nonmetropolitan counties not adjacent to a metropolitan area.

A total of 6,291 cases with a mean age of 75 years were included in the final analysis: 3,750 from metro areas, 2,235 from urban areas, and 306 from rural areas. A higher proportion of MCC patients from rural areas were male (69% vs. 62% from metro areas and 64% from urban areas) and white (97% vs. 95% and 96%, respectively). “This may contribute to differences in MCC care,” Dr. Larson said. “However, we also found that there is an increased incidence of locally staged disease in rural areas (51%) than in metro (44%) or urban (45%) areas (P = .02). In addition, fewer lymph node surgeries were performed in rural (50%) and urban (51%) areas than in metro areas (45%; P = .01).”

Overall survival was worse among patients in rural areas (a mean of 34 months), compared with those in urban (a mean of 41 months) and metro areas (a mean of 47 months; P = .02). “This may be due to the fact that rural counties have the higher risk factors for MCC incidence and death, but when we account for the confounders, including sex, age, race, and MCC stage, we still found a difference in overall survival in rural counties, compared to metro and urban counties,” Dr. Larson said.

Dr. Carroll, an associate professor of dermatology at University Hospitals of Cleveland, characterized the finding as “not what you’d expect with a higher incidence of local disease. Therefore, there is the potential for mis-staging in rural counties, where we did see that the interrogation of lymph nodes was done less frequently than in urban centers, which were more aligned with National Comprehensive Cancer Network guidelines during this time period. Still, after correction, rural location is still associated with a higher MCC mortality. There is a need for us to further interrogate what the causes are for this disparity in care between rural and urban centers.”

The other study authors were Dustin DeMeo and Christian Scheufele, MD. The researchers reported having no relevant financial disclosures.

[email protected]

The Diagnosis: Nevoid Basal Cell Carcinoma Syndrome

Nevoid basal cell carcinoma syndrome (NBCCS), also known as Gorlin syndrome, is a rare autosomal-dominant disorder that increases the risk for developing various carcinomas and affects multiple organ systems. Nevoid basal cell carcinoma syndrome is estimated at 1 per 40,000 to 60,000 individuals with no sexual predilection.^1,2 Pathogenesis of NBCCS occurs through molecular alterations in the dormant hedgehog signaling pathway, causing constitutive signaling activity and a loss of function in the tumor suppressor patched 1 gene, PTCH1. As a result, the inhibition of smoothened oncogenes is released, Gli proteins are activated, and the hedgehog signaling pathway is no longer quiescent.² Additional loss of function in the suppressor of fused homolog protein, a negative regulator of the hedgehog pathway, allows for further tumor proliferation. The crucial role these genes play in the hedgehog signaling pathway and their mutation association with NBCCS allows for molecular confirmation in the diagnosis of NBCCS. Allelic losses at the PTCH1 gene site are thought to occur in approximately 70% of NBCCS patients.²

Diagnosis of NBCCS is based on genetic testing to examine pathogenic gene variants, notably in the PTCH1 gene, and identification of characteristic clinical findings.² Diagnosis of NBCCS requires either 2 minor suggestive criteria and 1 major suggestive criterion, 2 major suggestive criteria and 1 minor suggestive criterion, or 1 major suggestive criterion with molecular confirmation. The presence of basal cell carcinomas (BCCs) before 20 years of age or an excessive numbers of BCCs, keratocystic odontogenic tumors (KOTs), palmar or plantar pitting, and first-degree relatives with NBCCS are classified as major suggestive criteria.² Nevoid basal cell carcinoma syndrome patients typically have BCCs that crust, ulcerate, or bleed. Minor suggestive criteria for NBCCS are rib abnormalities, skeletal malformations, macrocephaly, cleft lip or palate, and desmoplastic medulloblastoma.^2-4 Suppressor of fused homolog protein mutations may increase the risk for desmoplastic medulloblastoma in NBCCS patients. Our patient had 4 of the major suggestive criteria, including a history of KOTs, multiple BCCs, first-degree relatives with NBCCS, and palmar or plantar pitting (bottom quiz image), while having 1 minor suggestive criterion of frontal bossing.

Patients with NBCCS have high phenotypic variability, as their skin carcinomas do not have the classic features of pearly surfaces or corkscrew telangiectasia that typically are associated with BCCs.¹ Basal cell carcinomas in NBCCS-affected individuals usually are indistinguishable from sporadic lesions that arise in sun-exposed areas, making NBCCS difficult to diagnose. These sporadic lesions often are misdiagnosed as psoriatic or eczematous lesions, and additional subsequent examination is required. The findings of multiple papules and plaques spanning the body as well as lesions with rolled borders and ulcerated bases, indicative of BCCs, aid dermatologists in distinguishing benign lesions from those of NBCCS.¹

Additional differential diagnoses are required to distinguish NBCCS from other similar inherited skin disorders that are characterized by BCCs. The presence of multiple incidental BCCs early in life remains a histopathologic clue for NBCCS diagnosis, as opposed to Rombo syndrome, in which BCCs often develop in adulthood.^2,4 In addition, although both Bazex syndrome and Muir-Torre syndrome are characterized by the early onset of BCCs, the lack of skeletal abnormalities and palmar and plantar pitting distinguish these entities from NBCCS.^2,4 Furthermore, though psoriasis also can present on the scalp, clinical presentation often includes well-demarcated and symmetric plaques that are erythematous and silvery, all of which were not present in our patient and typically are not seen in NBCCS.⁵

The recommended treatment of NBCCS is vismodegib, a specific oncogene inhibitor. This medication suppresses the hedgehog signaling pathway by inhibiting smoothened oncogenes and downstream target molecules, thereby decreasing tumor proliferation.⁶ In doing so, vismodegib inhibits the development of new BCCs while reducing the burden of present ones. Additionally, vismodegib appears to effectively treat KOTs. If successful, this medication may be able to suppress KOTs in patients with NBCCS and thus facilitate surgery.⁶ Additional hedgehog inhibitors include patidegib, sonidegib, and itraconazole. Patidegib gel 2% currently is in phase 3 clinical trials for evaluation of efficacy and safety in treatment of NBCCS. Sonidegib is approved for the treatment of locally advanced BCCs in the United States and the European Union and for both locally advanced BCCs and metastatic BCCs in Switzerland and Australia.⁷ Further research is needed before recommending antifungal itraconazole for NBCCS clinical use.8 Other medications for localized areas include topical application of 5-fluorouracil and imiquimod.²

The Diagnosis: Nevoid Basal Cell Carcinoma Syndrome

Nevoid basal cell carcinoma syndrome (NBCCS), also known as Gorlin syndrome, is a rare autosomal-dominant disorder that increases the risk for developing various carcinomas and affects multiple organ systems. Nevoid basal cell carcinoma syndrome is estimated at 1 per 40,000 to 60,000 individuals with no sexual predilection.^1,2 Pathogenesis of NBCCS occurs through molecular alterations in the dormant hedgehog signaling pathway, causing constitutive signaling activity and a loss of function in the tumor suppressor patched 1 gene, PTCH1. As a result, the inhibition of smoothened oncogenes is released, Gli proteins are activated, and the hedgehog signaling pathway is no longer quiescent.² Additional loss of function in the suppressor of fused homolog protein, a negative regulator of the hedgehog pathway, allows for further tumor proliferation. The crucial role these genes play in the hedgehog signaling pathway and their mutation association with NBCCS allows for molecular confirmation in the diagnosis of NBCCS. Allelic losses at the PTCH1 gene site are thought to occur in approximately 70% of NBCCS patients.²

Diagnosis of NBCCS is based on genetic testing to examine pathogenic gene variants, notably in the PTCH1 gene, and identification of characteristic clinical findings.² Diagnosis of NBCCS requires either 2 minor suggestive criteria and 1 major suggestive criterion, 2 major suggestive criteria and 1 minor suggestive criterion, or 1 major suggestive criterion with molecular confirmation. The presence of basal cell carcinomas (BCCs) before 20 years of age or an excessive numbers of BCCs, keratocystic odontogenic tumors (KOTs), palmar or plantar pitting, and first-degree relatives with NBCCS are classified as major suggestive criteria.² Nevoid basal cell carcinoma syndrome patients typically have BCCs that crust, ulcerate, or bleed. Minor suggestive criteria for NBCCS are rib abnormalities, skeletal malformations, macrocephaly, cleft lip or palate, and desmoplastic medulloblastoma.^2-4 Suppressor of fused homolog protein mutations may increase the risk for desmoplastic medulloblastoma in NBCCS patients. Our patient had 4 of the major suggestive criteria, including a history of KOTs, multiple BCCs, first-degree relatives with NBCCS, and palmar or plantar pitting (bottom quiz image), while having 1 minor suggestive criterion of frontal bossing.

Patients with NBCCS have high phenotypic variability, as their skin carcinomas do not have the classic features of pearly surfaces or corkscrew telangiectasia that typically are associated with BCCs.¹ Basal cell carcinomas in NBCCS-affected individuals usually are indistinguishable from sporadic lesions that arise in sun-exposed areas, making NBCCS difficult to diagnose. These sporadic lesions often are misdiagnosed as psoriatic or eczematous lesions, and additional subsequent examination is required. The findings of multiple papules and plaques spanning the body as well as lesions with rolled borders and ulcerated bases, indicative of BCCs, aid dermatologists in distinguishing benign lesions from those of NBCCS.¹

Additional differential diagnoses are required to distinguish NBCCS from other similar inherited skin disorders that are characterized by BCCs. The presence of multiple incidental BCCs early in life remains a histopathologic clue for NBCCS diagnosis, as opposed to Rombo syndrome, in which BCCs often develop in adulthood.^2,4 In addition, although both Bazex syndrome and Muir-Torre syndrome are characterized by the early onset of BCCs, the lack of skeletal abnormalities and palmar and plantar pitting distinguish these entities from NBCCS.^2,4 Furthermore, though psoriasis also can present on the scalp, clinical presentation often includes well-demarcated and symmetric plaques that are erythematous and silvery, all of which were not present in our patient and typically are not seen in NBCCS.⁵

The recommended treatment of NBCCS is vismodegib, a specific oncogene inhibitor. This medication suppresses the hedgehog signaling pathway by inhibiting smoothened oncogenes and downstream target molecules, thereby decreasing tumor proliferation.⁶ In doing so, vismodegib inhibits the development of new BCCs while reducing the burden of present ones. Additionally, vismodegib appears to effectively treat KOTs. If successful, this medication may be able to suppress KOTs in patients with NBCCS and thus facilitate surgery.⁶ Additional hedgehog inhibitors include patidegib, sonidegib, and itraconazole. Patidegib gel 2% currently is in phase 3 clinical trials for evaluation of efficacy and safety in treatment of NBCCS. Sonidegib is approved for the treatment of locally advanced BCCs in the United States and the European Union and for both locally advanced BCCs and metastatic BCCs in Switzerland and Australia.⁷ Further research is needed before recommending antifungal itraconazole for NBCCS clinical use.8 Other medications for localized areas include topical application of 5-fluorouracil and imiquimod.²

The Diagnosis: Nevoid Basal Cell Carcinoma Syndrome

Nevoid basal cell carcinoma syndrome (NBCCS), also known as Gorlin syndrome, is a rare autosomal-dominant disorder that increases the risk for developing various carcinomas and affects multiple organ systems. Nevoid basal cell carcinoma syndrome is estimated at 1 per 40,000 to 60,000 individuals with no sexual predilection.^1,2 Pathogenesis of NBCCS occurs through molecular alterations in the dormant hedgehog signaling pathway, causing constitutive signaling activity and a loss of function in the tumor suppressor patched 1 gene, PTCH1. As a result, the inhibition of smoothened oncogenes is released, Gli proteins are activated, and the hedgehog signaling pathway is no longer quiescent.² Additional loss of function in the suppressor of fused homolog protein, a negative regulator of the hedgehog pathway, allows for further tumor proliferation. The crucial role these genes play in the hedgehog signaling pathway and their mutation association with NBCCS allows for molecular confirmation in the diagnosis of NBCCS. Allelic losses at the PTCH1 gene site are thought to occur in approximately 70% of NBCCS patients.²

Diagnosis of NBCCS is based on genetic testing to examine pathogenic gene variants, notably in the PTCH1 gene, and identification of characteristic clinical findings.² Diagnosis of NBCCS requires either 2 minor suggestive criteria and 1 major suggestive criterion, 2 major suggestive criteria and 1 minor suggestive criterion, or 1 major suggestive criterion with molecular confirmation. The presence of basal cell carcinomas (BCCs) before 20 years of age or an excessive numbers of BCCs, keratocystic odontogenic tumors (KOTs), palmar or plantar pitting, and first-degree relatives with NBCCS are classified as major suggestive criteria.² Nevoid basal cell carcinoma syndrome patients typically have BCCs that crust, ulcerate, or bleed. Minor suggestive criteria for NBCCS are rib abnormalities, skeletal malformations, macrocephaly, cleft lip or palate, and desmoplastic medulloblastoma.^2-4 Suppressor of fused homolog protein mutations may increase the risk for desmoplastic medulloblastoma in NBCCS patients. Our patient had 4 of the major suggestive criteria, including a history of KOTs, multiple BCCs, first-degree relatives with NBCCS, and palmar or plantar pitting (bottom quiz image), while having 1 minor suggestive criterion of frontal bossing.

Patients with NBCCS have high phenotypic variability, as their skin carcinomas do not have the classic features of pearly surfaces or corkscrew telangiectasia that typically are associated with BCCs.¹ Basal cell carcinomas in NBCCS-affected individuals usually are indistinguishable from sporadic lesions that arise in sun-exposed areas, making NBCCS difficult to diagnose. These sporadic lesions often are misdiagnosed as psoriatic or eczematous lesions, and additional subsequent examination is required. The findings of multiple papules and plaques spanning the body as well as lesions with rolled borders and ulcerated bases, indicative of BCCs, aid dermatologists in distinguishing benign lesions from those of NBCCS.¹

Additional differential diagnoses are required to distinguish NBCCS from other similar inherited skin disorders that are characterized by BCCs. The presence of multiple incidental BCCs early in life remains a histopathologic clue for NBCCS diagnosis, as opposed to Rombo syndrome, in which BCCs often develop in adulthood.^2,4 In addition, although both Bazex syndrome and Muir-Torre syndrome are characterized by the early onset of BCCs, the lack of skeletal abnormalities and palmar and plantar pitting distinguish these entities from NBCCS.^2,4 Furthermore, though psoriasis also can present on the scalp, clinical presentation often includes well-demarcated and symmetric plaques that are erythematous and silvery, all of which were not present in our patient and typically are not seen in NBCCS.⁵

The recommended treatment of NBCCS is vismodegib, a specific oncogene inhibitor. This medication suppresses the hedgehog signaling pathway by inhibiting smoothened oncogenes and downstream target molecules, thereby decreasing tumor proliferation.⁶ In doing so, vismodegib inhibits the development of new BCCs while reducing the burden of present ones. Additionally, vismodegib appears to effectively treat KOTs. If successful, this medication may be able to suppress KOTs in patients with NBCCS and thus facilitate surgery.⁶ Additional hedgehog inhibitors include patidegib, sonidegib, and itraconazole. Patidegib gel 2% currently is in phase 3 clinical trials for evaluation of efficacy and safety in treatment of NBCCS. Sonidegib is approved for the treatment of locally advanced BCCs in the United States and the European Union and for both locally advanced BCCs and metastatic BCCs in Switzerland and Australia.⁷ Further research is needed before recommending antifungal itraconazole for NBCCS clinical use.8 Other medications for localized areas include topical application of 5-fluorouracil and imiquimod.²

An analysis of open-access skin image datasets available to train machine-learning algorithms to identify skin cancer has revealed that darker skin types are markedly underrepresented in the databases, researchers in the United Kingdom report.

Out of 106,950 skin lesions documented in 21 open-access databases and 17 open-access atlases identified by David Wen, BMBCh, from the University of Oxford (England), and colleagues, 2,436 images contained information on Fitzpatrick skin type. Of these, “only 10 images were from individuals with Fitzpatrick skin type V, and only a single image was from an individual with Fitzpatrick skin type VI,” the researchers said. “The ethnicity of these individuals was either Brazilian or unknown.”

In two datasets containing 1,585 images with ethnicity data, “no images were from individuals with an African, Afro-Caribbean, or South Asian background,” Dr. Wen and colleagues noted. “Coupled with the geographical origins of datasets, there was massive under-representation of skin lesion images from darker-skinned populations.”

The results of their systematic review were presented at the National Cancer Research Institute Festival and published on Nov. 9, 2021, in The Lancet Digital Health. To the best of their knowledge, they wrote, this is “the first systematic review of publicly available skin lesion images comprising predominantly dermoscopic and macroscopic images available through open access datasets and atlases.”

Overall, 11 of 14 datasets (79%) were from North America, Europe, or Oceania among datasets with information on country of origin, the researchers said. Either dermoscopic images or macroscopic photographs were the only types of images available in 19 of 21 (91%) datasets. There was some variation in the clinical information available, with 81,662 images (76.4%) containing information on age, 82,848 images (77.5%) having information on gender, and 79,561 images having information about body site (74.4%).

The researchers explained that these datasets might be of limited use in a real-world setting where the images aren’t representative of the population. Artificial intelligence (AI) programs that train using images of patients with one skin type, for example, can potentially misdiagnose patients of another skin type, they said.

“AI programs hold a lot of potential for diagnosing skin cancer because it can look at pictures and quickly and cost-effectively evaluate any worrying spots on the skin,” Dr. Wen said in a press release from the NCRI Festival. “However, it’s important to know about the images and patients used to develop programs, as these influence which groups of people the programs will be most effective for in real-life settings. Research has shown that programs trained on images taken from people with lighter skin types only might not be as accurate for people with darker skin, and vice versa.”

There was also “limited information on who, how and why the images were taken,” Dr. Wen said in the release. “This has implications for the programs developed from these images, due to uncertainty around how they may perform in different groups of people, especially in those who aren’t well represented in datasets, such as those with darker skin. This can potentially lead to the exclusion or even harm of these groups from AI technologies.”

While there are no current guidelines for developing skin image datasets, quality standards are needed, according to the researchers.

“Ensuring equitable digital health includes building unbiased, representative datasets to ensure that the algorithms that are created benefit people of all backgrounds and skin types,” they concluded in the study.

Neil Steven, MBBS, MA, PhD, FRCP, an NCRI Skin Group member who was not involved with the research, stated in the press release that the results from the study by Dr. Wen and colleagues “raise concerns about the ability of AI to assist in skin cancer diagnosis, especially in a global context.”

“I hope this work will continue and help ensure that the progress we make in using AI in medicine will benefit all patients, recognizing that human skin color is highly diverse,” said Dr. Steven, honorary consultant in medical oncology at University Hospitals Birmingham (England) NHS Foundation Trust.

‘We need more images of everybody’

Dermatologist Adewole Adamson, MD, MPP, assistant professor in the department of internal medicine (division of dermatology) at the University of Texas at Austin, said in an interview that a “major potential downside” of algorithms not trained on diverse datasets is the potential for incorrect diagnoses.

“The harms of algorithms used for diagnostic purposes in the skin can be particularly significant because of the scalability of this technology. A lot of thought needs to be put into how these algorithms are developed and tested,” said Dr. Adamson, who reviewed the manuscript of The Lancet Digital Health study but was not involved with the research.

He referred to the results of a recently published study in JAMA Dermatology, which found that only 10% of studies used to develop or test deep-learning algorithms contained metadata on skin tone. “Furthermore, most datasets are from countries where darker skin types are not represented. [These] algorithms therefore likely underperform on people of darker skin types and thus, users should be wary,” Dr. Adamson said.

A consensus guideline should be developed for public AI algorithms, he said, which should have metadata containing information on sex, race/ethnicity, geographic location, skin type, and part of the body. “This distribution should also be reported in any publication of an algorithm so that users can see if the distribution of the population in the training data mirrors that of the population in which it is intended to be used,” he added.

Adam Friedman, MD, professor and chair of dermatology at George Washington University, Washington, who was not involved with the research, said that, while this issue of underrepresentation has been known in dermatology for some time, the strength of the Lancet study is that it is a large study, with a message of “we need more images of everybody.”

“This is probably the broadest study looking at every possible accessible resource and taking an organized approach,” Dr. Friedman said in an interview. “But I think it also raises some important points about how we think about skin tones and how we refer to them as well with respect to misusing classification schemes that we currently have.”

While using ethnicity data and certain Fitzpatrick skin types as a proxy for darker skin is a limitation of the metadata the study authors had available, it also highlights “a broader problem with respect to lexicon regarding skin tone,” he explained.

“Skin does not have a race, it doesn’t have an ethnicity,” Dr. Friedman said.

A dataset that contains not only different skin tones but how different dermatologic conditions look across skin tones is important. “If you just look at one photo of one skin tone, you missed the fact that clinical presentations can be so polymorphic, especially because of different skin tones,” Dr. Friedman said.

“We need to keep pushing this message to ensure that images keep getting collected. We [need to] ensure that there’s quality control with these images and that we’re disseminating them in a way that everyone has access, both from self-learning, but also to teach others,” said Dr. Friedman, coeditor of a recently introduced dermatology atlas showing skin conditions in different skin tones.

Adamson reports no relevant financial relationships. Dr. Friedman is a coeditor of a dermatology atlas supported by Allergan Aesthetics and SkinBetter Science. This study was funded by NHSX and the Health Foundation. Three authors reported being paid employees of Databiology at the time of the study. The other authors reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.
 

An analysis of open-access skin image datasets available to train machine-learning algorithms to identify skin cancer has revealed that darker skin types are markedly underrepresented in the databases, researchers in the United Kingdom report.

Out of 106,950 skin lesions documented in 21 open-access databases and 17 open-access atlases identified by David Wen, BMBCh, from the University of Oxford (England), and colleagues, 2,436 images contained information on Fitzpatrick skin type. Of these, “only 10 images were from individuals with Fitzpatrick skin type V, and only a single image was from an individual with Fitzpatrick skin type VI,” the researchers said. “The ethnicity of these individuals was either Brazilian or unknown.”

In two datasets containing 1,585 images with ethnicity data, “no images were from individuals with an African, Afro-Caribbean, or South Asian background,” Dr. Wen and colleagues noted. “Coupled with the geographical origins of datasets, there was massive under-representation of skin lesion images from darker-skinned populations.”

The results of their systematic review were presented at the National Cancer Research Institute Festival and published on Nov. 9, 2021, in The Lancet Digital Health. To the best of their knowledge, they wrote, this is “the first systematic review of publicly available skin lesion images comprising predominantly dermoscopic and macroscopic images available through open access datasets and atlases.”

Overall, 11 of 14 datasets (79%) were from North America, Europe, or Oceania among datasets with information on country of origin, the researchers said. Either dermoscopic images or macroscopic photographs were the only types of images available in 19 of 21 (91%) datasets. There was some variation in the clinical information available, with 81,662 images (76.4%) containing information on age, 82,848 images (77.5%) having information on gender, and 79,561 images having information about body site (74.4%).

The researchers explained that these datasets might be of limited use in a real-world setting where the images aren’t representative of the population. Artificial intelligence (AI) programs that train using images of patients with one skin type, for example, can potentially misdiagnose patients of another skin type, they said.

“AI programs hold a lot of potential for diagnosing skin cancer because it can look at pictures and quickly and cost-effectively evaluate any worrying spots on the skin,” Dr. Wen said in a press release from the NCRI Festival. “However, it’s important to know about the images and patients used to develop programs, as these influence which groups of people the programs will be most effective for in real-life settings. Research has shown that programs trained on images taken from people with lighter skin types only might not be as accurate for people with darker skin, and vice versa.”

There was also “limited information on who, how and why the images were taken,” Dr. Wen said in the release. “This has implications for the programs developed from these images, due to uncertainty around how they may perform in different groups of people, especially in those who aren’t well represented in datasets, such as those with darker skin. This can potentially lead to the exclusion or even harm of these groups from AI technologies.”

While there are no current guidelines for developing skin image datasets, quality standards are needed, according to the researchers.

“Ensuring equitable digital health includes building unbiased, representative datasets to ensure that the algorithms that are created benefit people of all backgrounds and skin types,” they concluded in the study.

Neil Steven, MBBS, MA, PhD, FRCP, an NCRI Skin Group member who was not involved with the research, stated in the press release that the results from the study by Dr. Wen and colleagues “raise concerns about the ability of AI to assist in skin cancer diagnosis, especially in a global context.”

“I hope this work will continue and help ensure that the progress we make in using AI in medicine will benefit all patients, recognizing that human skin color is highly diverse,” said Dr. Steven, honorary consultant in medical oncology at University Hospitals Birmingham (England) NHS Foundation Trust.

‘We need more images of everybody’

Dermatologist Adewole Adamson, MD, MPP, assistant professor in the department of internal medicine (division of dermatology) at the University of Texas at Austin, said in an interview that a “major potential downside” of algorithms not trained on diverse datasets is the potential for incorrect diagnoses.

“The harms of algorithms used for diagnostic purposes in the skin can be particularly significant because of the scalability of this technology. A lot of thought needs to be put into how these algorithms are developed and tested,” said Dr. Adamson, who reviewed the manuscript of The Lancet Digital Health study but was not involved with the research.

He referred to the results of a recently published study in JAMA Dermatology, which found that only 10% of studies used to develop or test deep-learning algorithms contained metadata on skin tone. “Furthermore, most datasets are from countries where darker skin types are not represented. [These] algorithms therefore likely underperform on people of darker skin types and thus, users should be wary,” Dr. Adamson said.

A consensus guideline should be developed for public AI algorithms, he said, which should have metadata containing information on sex, race/ethnicity, geographic location, skin type, and part of the body. “This distribution should also be reported in any publication of an algorithm so that users can see if the distribution of the population in the training data mirrors that of the population in which it is intended to be used,” he added.

Adam Friedman, MD, professor and chair of dermatology at George Washington University, Washington, who was not involved with the research, said that, while this issue of underrepresentation has been known in dermatology for some time, the strength of the Lancet study is that it is a large study, with a message of “we need more images of everybody.”

“This is probably the broadest study looking at every possible accessible resource and taking an organized approach,” Dr. Friedman said in an interview. “But I think it also raises some important points about how we think about skin tones and how we refer to them as well with respect to misusing classification schemes that we currently have.”

While using ethnicity data and certain Fitzpatrick skin types as a proxy for darker skin is a limitation of the metadata the study authors had available, it also highlights “a broader problem with respect to lexicon regarding skin tone,” he explained.

“Skin does not have a race, it doesn’t have an ethnicity,” Dr. Friedman said.

A dataset that contains not only different skin tones but how different dermatologic conditions look across skin tones is important. “If you just look at one photo of one skin tone, you missed the fact that clinical presentations can be so polymorphic, especially because of different skin tones,” Dr. Friedman said.

“We need to keep pushing this message to ensure that images keep getting collected. We [need to] ensure that there’s quality control with these images and that we’re disseminating them in a way that everyone has access, both from self-learning, but also to teach others,” said Dr. Friedman, coeditor of a recently introduced dermatology atlas showing skin conditions in different skin tones.

Adamson reports no relevant financial relationships. Dr. Friedman is a coeditor of a dermatology atlas supported by Allergan Aesthetics and SkinBetter Science. This study was funded by NHSX and the Health Foundation. Three authors reported being paid employees of Databiology at the time of the study. The other authors reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.
 

An analysis of open-access skin image datasets available to train machine-learning algorithms to identify skin cancer has revealed that darker skin types are markedly underrepresented in the databases, researchers in the United Kingdom report.

Out of 106,950 skin lesions documented in 21 open-access databases and 17 open-access atlases identified by David Wen, BMBCh, from the University of Oxford (England), and colleagues, 2,436 images contained information on Fitzpatrick skin type. Of these, “only 10 images were from individuals with Fitzpatrick skin type V, and only a single image was from an individual with Fitzpatrick skin type VI,” the researchers said. “The ethnicity of these individuals was either Brazilian or unknown.”

In two datasets containing 1,585 images with ethnicity data, “no images were from individuals with an African, Afro-Caribbean, or South Asian background,” Dr. Wen and colleagues noted. “Coupled with the geographical origins of datasets, there was massive under-representation of skin lesion images from darker-skinned populations.”

The results of their systematic review were presented at the National Cancer Research Institute Festival and published on Nov. 9, 2021, in The Lancet Digital Health. To the best of their knowledge, they wrote, this is “the first systematic review of publicly available skin lesion images comprising predominantly dermoscopic and macroscopic images available through open access datasets and atlases.”

Overall, 11 of 14 datasets (79%) were from North America, Europe, or Oceania among datasets with information on country of origin, the researchers said. Either dermoscopic images or macroscopic photographs were the only types of images available in 19 of 21 (91%) datasets. There was some variation in the clinical information available, with 81,662 images (76.4%) containing information on age, 82,848 images (77.5%) having information on gender, and 79,561 images having information about body site (74.4%).

The researchers explained that these datasets might be of limited use in a real-world setting where the images aren’t representative of the population. Artificial intelligence (AI) programs that train using images of patients with one skin type, for example, can potentially misdiagnose patients of another skin type, they said.

“AI programs hold a lot of potential for diagnosing skin cancer because it can look at pictures and quickly and cost-effectively evaluate any worrying spots on the skin,” Dr. Wen said in a press release from the NCRI Festival. “However, it’s important to know about the images and patients used to develop programs, as these influence which groups of people the programs will be most effective for in real-life settings. Research has shown that programs trained on images taken from people with lighter skin types only might not be as accurate for people with darker skin, and vice versa.”

There was also “limited information on who, how and why the images were taken,” Dr. Wen said in the release. “This has implications for the programs developed from these images, due to uncertainty around how they may perform in different groups of people, especially in those who aren’t well represented in datasets, such as those with darker skin. This can potentially lead to the exclusion or even harm of these groups from AI technologies.”

While there are no current guidelines for developing skin image datasets, quality standards are needed, according to the researchers.

“Ensuring equitable digital health includes building unbiased, representative datasets to ensure that the algorithms that are created benefit people of all backgrounds and skin types,” they concluded in the study.

Neil Steven, MBBS, MA, PhD, FRCP, an NCRI Skin Group member who was not involved with the research, stated in the press release that the results from the study by Dr. Wen and colleagues “raise concerns about the ability of AI to assist in skin cancer diagnosis, especially in a global context.”

“I hope this work will continue and help ensure that the progress we make in using AI in medicine will benefit all patients, recognizing that human skin color is highly diverse,” said Dr. Steven, honorary consultant in medical oncology at University Hospitals Birmingham (England) NHS Foundation Trust.

‘We need more images of everybody’

Dermatologist Adewole Adamson, MD, MPP, assistant professor in the department of internal medicine (division of dermatology) at the University of Texas at Austin, said in an interview that a “major potential downside” of algorithms not trained on diverse datasets is the potential for incorrect diagnoses.

“The harms of algorithms used for diagnostic purposes in the skin can be particularly significant because of the scalability of this technology. A lot of thought needs to be put into how these algorithms are developed and tested,” said Dr. Adamson, who reviewed the manuscript of The Lancet Digital Health study but was not involved with the research.

He referred to the results of a recently published study in JAMA Dermatology, which found that only 10% of studies used to develop or test deep-learning algorithms contained metadata on skin tone. “Furthermore, most datasets are from countries where darker skin types are not represented. [These] algorithms therefore likely underperform on people of darker skin types and thus, users should be wary,” Dr. Adamson said.

A consensus guideline should be developed for public AI algorithms, he said, which should have metadata containing information on sex, race/ethnicity, geographic location, skin type, and part of the body. “This distribution should also be reported in any publication of an algorithm so that users can see if the distribution of the population in the training data mirrors that of the population in which it is intended to be used,” he added.

Adam Friedman, MD, professor and chair of dermatology at George Washington University, Washington, who was not involved with the research, said that, while this issue of underrepresentation has been known in dermatology for some time, the strength of the Lancet study is that it is a large study, with a message of “we need more images of everybody.”

“This is probably the broadest study looking at every possible accessible resource and taking an organized approach,” Dr. Friedman said in an interview. “But I think it also raises some important points about how we think about skin tones and how we refer to them as well with respect to misusing classification schemes that we currently have.”

While using ethnicity data and certain Fitzpatrick skin types as a proxy for darker skin is a limitation of the metadata the study authors had available, it also highlights “a broader problem with respect to lexicon regarding skin tone,” he explained.

“Skin does not have a race, it doesn’t have an ethnicity,” Dr. Friedman said.

A dataset that contains not only different skin tones but how different dermatologic conditions look across skin tones is important. “If you just look at one photo of one skin tone, you missed the fact that clinical presentations can be so polymorphic, especially because of different skin tones,” Dr. Friedman said.

“We need to keep pushing this message to ensure that images keep getting collected. We [need to] ensure that there’s quality control with these images and that we’re disseminating them in a way that everyone has access, both from self-learning, but also to teach others,” said Dr. Friedman, coeditor of a recently introduced dermatology atlas showing skin conditions in different skin tones.

Adamson reports no relevant financial relationships. Dr. Friedman is a coeditor of a dermatology atlas supported by Allergan Aesthetics and SkinBetter Science. This study was funded by NHSX and the Health Foundation. Three authors reported being paid employees of Databiology at the time of the study. The other authors reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.
 

The Boswellia serrata exudate or gum (known in India as “guggulu”) that forms an aromatic resin traditionally used as incense – and known as frankincense (especially when retrieved from Boswellia species found in Eritrea and Somalia but also from the Indian variety) – has been considered for thousands of years to possess therapeutic properties. It is used in Ayurvedic medicine, as well as in traditional medicine in China and the Middle East, particularly for its anti-inflammatory effects to treat chronic conditions.^1-8 In fact, such essential oils have been used since 2800 BC to treat various inflammatory conditions, including skin sores and wounds, as well as in perfumes and incense.^2,9 In the West, use of frankincense dates back to thousands of years as well, more often found in the form of incense for religious and cultural ceremonies.⁷ Over the past 2 decades, evidence supporting the use of frankincense for therapeutic medical purposes has increased, particularly because of its purported anti-inflammatory and anticancer properties.³ This column focuses on some of the emerging data on this ancient botanical agent.

Madeleine_Steinbach / iStock / Getty Images Plus

Chemical constituents

Terpenoids and essential oils are the primary components of frankincense and are known to impart anti-inflammatory and anticancer activity. The same is true for myrrh, which has been combined with frankincense in traditional Chinese medicine as a single medication for millennia, with the two acting synergistically and considered still to be a potent combination in conferring various biological benefits.⁷

In 2010, in a systematic review of the anti-inflammatory and anticancer activities of Boswellia species and their chemical ingredients, Efferth and Oesch found that frankincense blocks the production of leukotrienes, cyclooxygenase (COX) 1 and 2, as well as 5-lipoxygenase; and oxidative stress. It also contributes to regulation of immune cells from the innate and acquired immune systems and exerts anticancer activity by influencing signaling transduction responsible for cell cycle arrest, as well as inhibition of proliferation, angiogenesis, invasion, and metastasis. The investigators also reported on clinical trial results that have found efficacy of frankincense and its constituents in ameliorating symptoms of psoriasis and erythematous eczema, among other disorders.³

Anti-inflammatory activity

Li et al. completed a study in 2016 to identify the active ingredients responsible for the anti-inflammatory and analgesic effects of frankincense. They found that alpha-pinene, linalool, and 1-octanol were key contributors. These constituents were noted for suppressing COX-2 overexpression in mice, as well as nociceptive stimulus-induced inflammatory infiltrates.¹⁰

Noting the increasing popularity of frankincense essential oil in skin care, despite a paucity of data, in 2017, Han et al. evaluated the biological activities of the essential oil in pre-inflamed human dermal fibroblasts using 17 key protein biomarkers. Frankincense essential oil displayed significant antiproliferative activity and suppressed collagen III, interferon gamma-induced protein 10, and intracellular adhesion molecule 1. The investigators referred to the overall encouraging potential of frankincense essential oil to exert influence over inflammation and tissue remodeling in human skin and called for additional research into its mechanisms of action and active constituents.¹¹

Anticancer activity

The main active ingredient in frankincense, boswellic acid, has been shown to promote apoptosis, suppress matrix metalloproteinase secretion, and hinder migration in metastatic melanoma cell lines in mice.^6,12

In 2019, Hakkim et al. demonstrated that frankincense essential oil yielded substantial antimelanoma activity in vitro and in vivo and ameliorated hepatotoxicity caused by acetaminophen.¹³

There is one case report in the literature on the use of frankincense as a treatment for skin cancer. A 56-year-old man received frankincense oil multiple times a day for 4 months to treat a nodular basal cell carcinoma on one arm (which resolved) and an infiltrative BCC on the chest (some focal residual tumor remained).^6,14 Topical frankincense or boswellic acid has been given a grade D recommendation for treating skin cancer, however, because of only one level-of-evidence-5 study.⁶

Antimicrobial activity

In 2012, de Rapper et al. collected samples of three essential oils of frankincense (Boswellia rivae, Boswellia neglecta, and Boswellia papyrifera) and two essential oil samples of myrrh and sweet myrrh from different regions of Ethiopia to study their anti-infective properties alone and in combination. The investigators observed synergistic and additive effects, particularly between B. papyrifera and Commiphora myrrha. While noting the long history of the combined use of frankincense and myrrh essential oils since 1500 BC, the investigators highlighted their study as the first antimicrobial work to verify the effectiveness of this combination, validating the use of this combination to thwart particular pathogens.¹⁵

Just 2 years ago, Ljaljević Grbić et al. evaluated the in vitro antimicrobial potential of the liquid and vapor phases of B. carteri and C. myrrha (frankincense and myrrh, respectively) essential oils, finding that frankincense demonstrated marked capacity to act as a natural antimicrobial agent.⁹

Transdermal delivery

In 2017, Zhu et al. showed that frankincense and myrrh essential oils promoted the permeability of the Chinese herb Chuanxiong and may facilitate drug elimination from the epidermis via dermal capillaries by dint of improved cutaneous blood flow, thereby augmenting transdermal drug delivery.¹⁶ The same team also showed that frankincense and myrrh essential oils, by fostering permeation by enhancing drug delivery across the stratum corneum, can also alter the structure of the stratum corneum.¹⁷

Conclusion

The use of frankincense in traditional medicine has a long and impressive track record. Recent research provides reason for optimism, and further investigating the possible incorporation of this botanical agent into modern dermatologic therapies appears warranted. Clearly, however, much more research is needed.

Dr. Baumann is a private practice dermatologist, researcher, author, and entrepreneur who practices in Miami. She founded the Cosmetic Dermatology Center at the University of Miami in 1997. Dr. Baumann has written two textbooks and a New York Times Best Sellers book for consumers. Dr. Baumann has received funding for advisory boards and/or clinical research trials from Allergan, Galderma, Revance, Evolus, and Burt’s Bees. She is the CEO of Skin Type Solutions Inc., a company that independently tests skin care products and makes recommendations to physicians on which skin care technologies are best. Write to her at [email protected].

References

1. Kimmatkar N et al. Phytomedicine. 2003 Jan;10(1):3-7.

2. Ammon HP. Wien Med Wochenschr. 2002;152(15-16):373-8.

3. Efferth T & Oesch F. Semin Cancer Biol. 2020 Feb 4;S1044-579X(20)30034-1.

4. Banno N et al. J Ethnopharmacol. 2006 Sep 19;107(2):249-53.

5. Poeckel D & Werz O. Curr Med Chem. 2006;13(28):3359-69.

6. Li JY, Kampp JT. Dermatol Surg. 2019 Jan;45(1):58-67.

7. Cao B et al. Molecules. 2019 Aug 24;24(17): 3076.

8. Mertens M et al. Flavour Fragr J. 2009;24:279-300.

9. Ljaljević Grbić M et al. J Ethnopharmacol. 2018 Jun 12;219:1-14.

10. Li XJ et al. J Ethnopharmacol. 2016 Feb 17;179:22-6.

11. Han X et al. Biochim Open. 2017 Feb 3;4:31-5.

12. Zhao W et al. Cancer Detect Prev. 2003;27:67-75.

13. Hakkim FL et al. Oncotarget. 2019 May 28;10(37):3472-90.

14. Fung K et al. OA Altern Med 2013;1:14.

15. de Rapper S et al. Lett Appl Microbiol. 2012 Apr;54(4):352-8.

16. Zhu XF et al. Zhongguo Zhong Yao Za Zhi. 2017 Feb;42(4):680-5.

17. Guan YM et al. Zhongguo Zhong Yao Za Zhi. 2017 Sep;42(17):3350-5.

The Boswellia serrata exudate or gum (known in India as “guggulu”) that forms an aromatic resin traditionally used as incense – and known as frankincense (especially when retrieved from Boswellia species found in Eritrea and Somalia but also from the Indian variety) – has been considered for thousands of years to possess therapeutic properties. It is used in Ayurvedic medicine, as well as in traditional medicine in China and the Middle East, particularly for its anti-inflammatory effects to treat chronic conditions.^1-8 In fact, such essential oils have been used since 2800 BC to treat various inflammatory conditions, including skin sores and wounds, as well as in perfumes and incense.^2,9 In the West, use of frankincense dates back to thousands of years as well, more often found in the form of incense for religious and cultural ceremonies.⁷ Over the past 2 decades, evidence supporting the use of frankincense for therapeutic medical purposes has increased, particularly because of its purported anti-inflammatory and anticancer properties.³ This column focuses on some of the emerging data on this ancient botanical agent.

Madeleine_Steinbach / iStock / Getty Images Plus

Chemical constituents

Terpenoids and essential oils are the primary components of frankincense and are known to impart anti-inflammatory and anticancer activity. The same is true for myrrh, which has been combined with frankincense in traditional Chinese medicine as a single medication for millennia, with the two acting synergistically and considered still to be a potent combination in conferring various biological benefits.⁷

In 2010, in a systematic review of the anti-inflammatory and anticancer activities of Boswellia species and their chemical ingredients, Efferth and Oesch found that frankincense blocks the production of leukotrienes, cyclooxygenase (COX) 1 and 2, as well as 5-lipoxygenase; and oxidative stress. It also contributes to regulation of immune cells from the innate and acquired immune systems and exerts anticancer activity by influencing signaling transduction responsible for cell cycle arrest, as well as inhibition of proliferation, angiogenesis, invasion, and metastasis. The investigators also reported on clinical trial results that have found efficacy of frankincense and its constituents in ameliorating symptoms of psoriasis and erythematous eczema, among other disorders.³

Anti-inflammatory activity

Li et al. completed a study in 2016 to identify the active ingredients responsible for the anti-inflammatory and analgesic effects of frankincense. They found that alpha-pinene, linalool, and 1-octanol were key contributors. These constituents were noted for suppressing COX-2 overexpression in mice, as well as nociceptive stimulus-induced inflammatory infiltrates.¹⁰

Noting the increasing popularity of frankincense essential oil in skin care, despite a paucity of data, in 2017, Han et al. evaluated the biological activities of the essential oil in pre-inflamed human dermal fibroblasts using 17 key protein biomarkers. Frankincense essential oil displayed significant antiproliferative activity and suppressed collagen III, interferon gamma-induced protein 10, and intracellular adhesion molecule 1. The investigators referred to the overall encouraging potential of frankincense essential oil to exert influence over inflammation and tissue remodeling in human skin and called for additional research into its mechanisms of action and active constituents.¹¹

Anticancer activity

The main active ingredient in frankincense, boswellic acid, has been shown to promote apoptosis, suppress matrix metalloproteinase secretion, and hinder migration in metastatic melanoma cell lines in mice.^6,12

In 2019, Hakkim et al. demonstrated that frankincense essential oil yielded substantial antimelanoma activity in vitro and in vivo and ameliorated hepatotoxicity caused by acetaminophen.¹³

There is one case report in the literature on the use of frankincense as a treatment for skin cancer. A 56-year-old man received frankincense oil multiple times a day for 4 months to treat a nodular basal cell carcinoma on one arm (which resolved) and an infiltrative BCC on the chest (some focal residual tumor remained).^6,14 Topical frankincense or boswellic acid has been given a grade D recommendation for treating skin cancer, however, because of only one level-of-evidence-5 study.⁶

Antimicrobial activity

In 2012, de Rapper et al. collected samples of three essential oils of frankincense (Boswellia rivae, Boswellia neglecta, and Boswellia papyrifera) and two essential oil samples of myrrh and sweet myrrh from different regions of Ethiopia to study their anti-infective properties alone and in combination. The investigators observed synergistic and additive effects, particularly between B. papyrifera and Commiphora myrrha. While noting the long history of the combined use of frankincense and myrrh essential oils since 1500 BC, the investigators highlighted their study as the first antimicrobial work to verify the effectiveness of this combination, validating the use of this combination to thwart particular pathogens.¹⁵

Just 2 years ago, Ljaljević Grbić et al. evaluated the in vitro antimicrobial potential of the liquid and vapor phases of B. carteri and C. myrrha (frankincense and myrrh, respectively) essential oils, finding that frankincense demonstrated marked capacity to act as a natural antimicrobial agent.⁹

Transdermal delivery

In 2017, Zhu et al. showed that frankincense and myrrh essential oils promoted the permeability of the Chinese herb Chuanxiong and may facilitate drug elimination from the epidermis via dermal capillaries by dint of improved cutaneous blood flow, thereby augmenting transdermal drug delivery.¹⁶ The same team also showed that frankincense and myrrh essential oils, by fostering permeation by enhancing drug delivery across the stratum corneum, can also alter the structure of the stratum corneum.¹⁷

Conclusion

The use of frankincense in traditional medicine has a long and impressive track record. Recent research provides reason for optimism, and further investigating the possible incorporation of this botanical agent into modern dermatologic therapies appears warranted. Clearly, however, much more research is needed.

Dr. Baumann is a private practice dermatologist, researcher, author, and entrepreneur who practices in Miami. She founded the Cosmetic Dermatology Center at the University of Miami in 1997. Dr. Baumann has written two textbooks and a New York Times Best Sellers book for consumers. Dr. Baumann has received funding for advisory boards and/or clinical research trials from Allergan, Galderma, Revance, Evolus, and Burt’s Bees. She is the CEO of Skin Type Solutions Inc., a company that independently tests skin care products and makes recommendations to physicians on which skin care technologies are best. Write to her at [email protected].

References

1. Kimmatkar N et al. Phytomedicine. 2003 Jan;10(1):3-7.

2. Ammon HP. Wien Med Wochenschr. 2002;152(15-16):373-8.

3. Efferth T & Oesch F. Semin Cancer Biol. 2020 Feb 4;S1044-579X(20)30034-1.

4. Banno N et al. J Ethnopharmacol. 2006 Sep 19;107(2):249-53.

5. Poeckel D & Werz O. Curr Med Chem. 2006;13(28):3359-69.

6. Li JY, Kampp JT. Dermatol Surg. 2019 Jan;45(1):58-67.

7. Cao B et al. Molecules. 2019 Aug 24;24(17): 3076.

8. Mertens M et al. Flavour Fragr J. 2009;24:279-300.

9. Ljaljević Grbić M et al. J Ethnopharmacol. 2018 Jun 12;219:1-14.

10. Li XJ et al. J Ethnopharmacol. 2016 Feb 17;179:22-6.

11. Han X et al. Biochim Open. 2017 Feb 3;4:31-5.

12. Zhao W et al. Cancer Detect Prev. 2003;27:67-75.

13. Hakkim FL et al. Oncotarget. 2019 May 28;10(37):3472-90.

14. Fung K et al. OA Altern Med 2013;1:14.

15. de Rapper S et al. Lett Appl Microbiol. 2012 Apr;54(4):352-8.

16. Zhu XF et al. Zhongguo Zhong Yao Za Zhi. 2017 Feb;42(4):680-5.

17. Guan YM et al. Zhongguo Zhong Yao Za Zhi. 2017 Sep;42(17):3350-5.

The Boswellia serrata exudate or gum (known in India as “guggulu”) that forms an aromatic resin traditionally used as incense – and known as frankincense (especially when retrieved from Boswellia species found in Eritrea and Somalia but also from the Indian variety) – has been considered for thousands of years to possess therapeutic properties. It is used in Ayurvedic medicine, as well as in traditional medicine in China and the Middle East, particularly for its anti-inflammatory effects to treat chronic conditions.^1-8 In fact, such essential oils have been used since 2800 BC to treat various inflammatory conditions, including skin sores and wounds, as well as in perfumes and incense.^2,9 In the West, use of frankincense dates back to thousands of years as well, more often found in the form of incense for religious and cultural ceremonies.⁷ Over the past 2 decades, evidence supporting the use of frankincense for therapeutic medical purposes has increased, particularly because of its purported anti-inflammatory and anticancer properties.³ This column focuses on some of the emerging data on this ancient botanical agent.

Madeleine_Steinbach / iStock / Getty Images Plus

Chemical constituents

Terpenoids and essential oils are the primary components of frankincense and are known to impart anti-inflammatory and anticancer activity. The same is true for myrrh, which has been combined with frankincense in traditional Chinese medicine as a single medication for millennia, with the two acting synergistically and considered still to be a potent combination in conferring various biological benefits.⁷

In 2010, in a systematic review of the anti-inflammatory and anticancer activities of Boswellia species and their chemical ingredients, Efferth and Oesch found that frankincense blocks the production of leukotrienes, cyclooxygenase (COX) 1 and 2, as well as 5-lipoxygenase; and oxidative stress. It also contributes to regulation of immune cells from the innate and acquired immune systems and exerts anticancer activity by influencing signaling transduction responsible for cell cycle arrest, as well as inhibition of proliferation, angiogenesis, invasion, and metastasis. The investigators also reported on clinical trial results that have found efficacy of frankincense and its constituents in ameliorating symptoms of psoriasis and erythematous eczema, among other disorders.³

Anti-inflammatory activity

Li et al. completed a study in 2016 to identify the active ingredients responsible for the anti-inflammatory and analgesic effects of frankincense. They found that alpha-pinene, linalool, and 1-octanol were key contributors. These constituents were noted for suppressing COX-2 overexpression in mice, as well as nociceptive stimulus-induced inflammatory infiltrates.¹⁰

Noting the increasing popularity of frankincense essential oil in skin care, despite a paucity of data, in 2017, Han et al. evaluated the biological activities of the essential oil in pre-inflamed human dermal fibroblasts using 17 key protein biomarkers. Frankincense essential oil displayed significant antiproliferative activity and suppressed collagen III, interferon gamma-induced protein 10, and intracellular adhesion molecule 1. The investigators referred to the overall encouraging potential of frankincense essential oil to exert influence over inflammation and tissue remodeling in human skin and called for additional research into its mechanisms of action and active constituents.¹¹

Anticancer activity

The main active ingredient in frankincense, boswellic acid, has been shown to promote apoptosis, suppress matrix metalloproteinase secretion, and hinder migration in metastatic melanoma cell lines in mice.^6,12

In 2019, Hakkim et al. demonstrated that frankincense essential oil yielded substantial antimelanoma activity in vitro and in vivo and ameliorated hepatotoxicity caused by acetaminophen.¹³

There is one case report in the literature on the use of frankincense as a treatment for skin cancer. A 56-year-old man received frankincense oil multiple times a day for 4 months to treat a nodular basal cell carcinoma on one arm (which resolved) and an infiltrative BCC on the chest (some focal residual tumor remained).^6,14 Topical frankincense or boswellic acid has been given a grade D recommendation for treating skin cancer, however, because of only one level-of-evidence-5 study.⁶

Antimicrobial activity

In 2012, de Rapper et al. collected samples of three essential oils of frankincense (Boswellia rivae, Boswellia neglecta, and Boswellia papyrifera) and two essential oil samples of myrrh and sweet myrrh from different regions of Ethiopia to study their anti-infective properties alone and in combination. The investigators observed synergistic and additive effects, particularly between B. papyrifera and Commiphora myrrha. While noting the long history of the combined use of frankincense and myrrh essential oils since 1500 BC, the investigators highlighted their study as the first antimicrobial work to verify the effectiveness of this combination, validating the use of this combination to thwart particular pathogens.¹⁵

Just 2 years ago, Ljaljević Grbić et al. evaluated the in vitro antimicrobial potential of the liquid and vapor phases of B. carteri and C. myrrha (frankincense and myrrh, respectively) essential oils, finding that frankincense demonstrated marked capacity to act as a natural antimicrobial agent.⁹

Transdermal delivery

In 2017, Zhu et al. showed that frankincense and myrrh essential oils promoted the permeability of the Chinese herb Chuanxiong and may facilitate drug elimination from the epidermis via dermal capillaries by dint of improved cutaneous blood flow, thereby augmenting transdermal drug delivery.¹⁶ The same team also showed that frankincense and myrrh essential oils, by fostering permeation by enhancing drug delivery across the stratum corneum, can also alter the structure of the stratum corneum.¹⁷

Conclusion

The use of frankincense in traditional medicine has a long and impressive track record. Recent research provides reason for optimism, and further investigating the possible incorporation of this botanical agent into modern dermatologic therapies appears warranted. Clearly, however, much more research is needed.

Dr. Baumann is a private practice dermatologist, researcher, author, and entrepreneur who practices in Miami. She founded the Cosmetic Dermatology Center at the University of Miami in 1997. Dr. Baumann has written two textbooks and a New York Times Best Sellers book for consumers. Dr. Baumann has received funding for advisory boards and/or clinical research trials from Allergan, Galderma, Revance, Evolus, and Burt’s Bees. She is the CEO of Skin Type Solutions Inc., a company that independently tests skin care products and makes recommendations to physicians on which skin care technologies are best. Write to her at [email protected].

References

1. Kimmatkar N et al. Phytomedicine. 2003 Jan;10(1):3-7.

2. Ammon HP. Wien Med Wochenschr. 2002;152(15-16):373-8.

3. Efferth T & Oesch F. Semin Cancer Biol. 2020 Feb 4;S1044-579X(20)30034-1.

4. Banno N et al. J Ethnopharmacol. 2006 Sep 19;107(2):249-53.

5. Poeckel D & Werz O. Curr Med Chem. 2006;13(28):3359-69.

6. Li JY, Kampp JT. Dermatol Surg. 2019 Jan;45(1):58-67.

7. Cao B et al. Molecules. 2019 Aug 24;24(17): 3076.

8. Mertens M et al. Flavour Fragr J. 2009;24:279-300.

9. Ljaljević Grbić M et al. J Ethnopharmacol. 2018 Jun 12;219:1-14.

10. Li XJ et al. J Ethnopharmacol. 2016 Feb 17;179:22-6.

11. Han X et al. Biochim Open. 2017 Feb 3;4:31-5.

12. Zhao W et al. Cancer Detect Prev. 2003;27:67-75.

13. Hakkim FL et al. Oncotarget. 2019 May 28;10(37):3472-90.

14. Fung K et al. OA Altern Med 2013;1:14.

15. de Rapper S et al. Lett Appl Microbiol. 2012 Apr;54(4):352-8.

16. Zhu XF et al. Zhongguo Zhong Yao Za Zhi. 2017 Feb;42(4):680-5.

17. Guan YM et al. Zhongguo Zhong Yao Za Zhi. 2017 Sep;42(17):3350-5.

Pilomatrix carcinoma is a rare adnexal tumor with origin from the germinative matrical cells of the hair follicle. Clinically, it presents as a solitary lesion commonly found in the head and neck region as well as the upper back. The tumors cannot be distinguished by their clinical appearance only and frequently are mistaken for cysts. Histopathologic examination provides the definitive diagnosis in most cases. These carcinomas are aggressive neoplasms with a high probability of local recurrence and distant metastasis. Assessment of the Wnt signaling pathway components such as β-catenin, lymphoid enhancer-binding factor 1 (LEF-1), and caudal-related homeobox transcription factor 2 (CDX-2) potentially can be used for diagnostic purposes and targeted therapy.

We report a rare and unique case of early pilomatrix carcinoma with intralesional melanocytes. We review the molecular pathology and pathogenesis of these carcinomas as well as the significance of early diagnosis.

Case Report

A 73-year-old man with a history of extensive sun exposure presented with a 1-cm, raised, rapidly growing, slightly irregular, purple lesion on the right forearm of 3 months’ duration with tendency to bleed. He did not have a history of skin cancers and was otherwise healthy. Excision was recommended due to the progressive and rapid growth of the lesion.

Histopathologic Findings—Gross examination revealed a 0.9×0.7-cm, raised, slightly irregular lesion located 1 mm away from the closest peripheral margin. Histologically, the lesion was a relatively circumscribed, dermal-based basaloid neoplasm with slightly ill-defined edges involving the superficial and deep dermis (Figure 1A). The neoplasm was formed predominantly of sheets of basaloid cells and small nests of ghost cells, in addition to some squamoid and transitional cells (Figure 1B). The basaloid cells exhibited severe nuclear atypia, pleomorphism, increased nuclear to cytoplasmic ratio (Figure 1C), minimal to moderate amounts of eosinophilic cytoplasm, enlarged nuclei, prominent nucleoli, and coarse chromatin pattern. Abundant mitotic activity and apoptotic bodies were present as well as focal area of central necrosis (Figure 1C). Also, melanophages and a multinucleated giant cell reaction was noted. Elastic trichrome special stain highlighted focal infiltration of the neoplastic cells into the adjacent desmoplastic stroma. Melanin stain was negative for melanin pigment within the neoplasm. Given the presence of severely atypical basaloid cells along with ghost cells indicating matrical differentiation, a diagnosis of pilomatrix carcinoma was rendered.

Immunohistochemistry—The neoplastic cells were diffusely positive for p63, CDX-2 (Figure 2A), β-catenin (Figure 2B), and CD10 (Figure 2C), and focally and weakly positive for cytokeratin (CK) 5, BerEP4 (staining the tumor periphery), androgen receptor, and CK18 (a low-molecular-weight keratin). They were negative for monoclonal carcinoembryonic antigen, epithelial membrane antigen, CK7, CK20, CD34, SOX-10, CD56, synaptophysin, and chromogranin. Cytokeratin 14 was positive in the squamoid cells but negative in the basaloid cells. SOX-10 and melanoma cocktail immunostains demonstrated few intralesional dendritic melanocytes.

Comment

Pilomatrix carcinoma is a rare malignant cutaneous adnexal neoplasm with origin from the germinative matrix of the hair bulb region of hair follicles. Pilomatrix carcinoma was first reported in 1980.^1,2 These tumors are characterized by rapid growth and aggressive behavior. Their benign counterpart, pilomatrixoma, is a slow-growing, dermal or subcutaneous tumor that rarely recurs after complete excision.

As with pilomatrixoma, pilomatrix carcinomas are asymptomatic and present as solitary dermal or subcutaneous masses^3,4 that most commonly are found in the posterior neck, upper back, and preauricular regions of middle-aged or elderly adults with male predominance.⁵ They range in size from 0.5 to 20 cm with a mean of 4 cm that is slightly larger than pilomatrixoma. Pilomatrix carcinomas predominantly are firm tumors with or without cystic components, and they exhibit a high probability of recurrence and have risk for distant metastasis.^6-15

The differential diagnosis includes epidermal cysts, pilomatrixoma, basal cell carcinoma with matrical differentiation, trichoblastoma/trichoblastic carcinoma, and trichilemmal carcinoma. Pilomatrix carcinomas frequently are mistaken for epidermal cysts on clinical examination. Such a distinction can be easily resolved by histopathologic evaluation. The more challenging differential diagnosis is with pilomatrixoma. Histologically, pilomatrixomas consist of a distinct population of cells including basaloid, squamoid, transitional, and shadow cells in variable proportions. The basaloid cells transition to shadow cells in an organized zonal fashion.¹⁶ Compared to pilomatrixomas, pilomatrix carcinomas often show predominance of the basaloid cells; marked cytologic atypia and pleomorphism; numerous mitotic figures; deep infiltrative pattern into subcutaneous fat, fascia, and skeletal muscle; stromal desmoplasia; necrosis; and neurovascular invasion (Tables 1 and 2). Furthermore, the shadow cells tend to form a small nested pattern in pilomatrix carcinoma instead of the flat sheetlike pattern usually observed in pilomatrixoma.¹⁶ Basal cell carcinoma with matrical differentiation can pose a diagnostic challenge in the differential diagnosis; basal cell carcinoma usually exhibits a peripheral palisade of the basaloid cells accompanied by retraction spaces separating the tumor from the stroma. Trichoblastoma/trichoblastic carcinoma with matrical differentiation can be distinguished by its exuberant stroma, prominent primitive hair follicles, and papillary mesenchymal bodies. Trichilemmal carcinomas are recognized by their connection to the overlying epidermis, peripheral palisading, and presence of clear cells, while pilomatrix carcinoma lacks connection to the surface epithelium.

Immunohistochemical stains have little to no role in the differential diagnosis, and morphology is the mainstay in making the diagnosis. Rarely, pilomatrix carcinoma can be confused with poorly differentiated sebaceous carcinoma and poorly differentiated squamous cell carcinoma. Although careful scrutiny of the histologic features may help identify mature sebocytes in sebaceous carcinoma, evidence of keratinization in squamous cell carcinoma and ghost cells in pilomatrix carcinoma, using a panel of immunohistochemical stains can be helpful in reaching the final diagnosis (Table 3).

The development of hair matrix tumors have been known to harbor mutations in exon 3 of the catenin beta-1 gene, CTNNB1, that encodes for β-catenin, a downstream effector in the Wnt signaling pathway responsible for differentiation, proliferation, and adhesion of epithelial stem cells.^17-21 In a study conducted by Kazakov et al,²² DNA was extracted from 86 lesions: 4 were pilomatrixomas and 1 was a pilomatrix carcinoma. A polymerase chain reaction assay revealed 8 pathogenic variants of the β-catenin gene. D32Y (CTNNB1):c.94G>T (p.Asp32Tyr) and G34R (CTNNB1):c.100G>C (p.Gly34Arg) were the mutations present in pilomatrixoma and pilomatrix carcinoma, respectively.²² In addition, there are several proteins that are part of the Wnt pathway in addition to β-catenin—LEF-1 and CDX-2.

Tumminello and Hosler²³ found that pilomatrixomas and pilomatrix carcinomas were positive for CDX-2, β-catenin, and LEF-1 by immunohistochemistry. These downstream molecules in the Wnt signaling pathway could have the potential to be used as diagnostic and prognostic markers.^2,13,15,23

Although the pathogenesis is unclear, there are 2 possible mechanisms by which pilomatrix carcinomas develop. They can either arise as de novo tumors, or it is possible that initial mutations in β-catenin result in the formation of pilomatrixomas at an early age that may undergo malignant transformation in elderly patients over time with additional mutations.²

Our case was strongly and diffusely positive for β-catenin in a nuclear and cytoplasmic pattern and CDX-2 in a nuclear pattern, supporting the role of the Wnt signaling pathway in such tumors. Furthermore, our case demonstrated the presence of few intralesional normal dendritic melanocytes, a rare finding^1,24,25 but not unexpected, as melanocytes normally are present within the hair follicle matrix.

Pilomatrix carcinomas are aggressive tumors with a high risk for local recurrence and tendency for metastasis. In a study of 13 cases of pilomatrix carcinomas, Herrmann et al¹³ found that metastasis was significantly associated with local tumor recurrence (P<.0413). They concluded that the combination of overall high local recurrence and metastatic rates of pilomatrix carcinoma as well as documented tumor-related deaths would warrant continued patient follow-up, especially for recurrent tumors.¹³ Rapid growth of a tumor, either de novo or following several months of stable size, should alert physicians to perform a diagnostic biopsy.

Management options of pilomatrix carcinoma include surgery or radiation with close follow-up. The most widely reported treatment of pilomatrix carcinoma is wide local excision with histologically confirmed clear margins. Mohs micrographic surgery is an excellent treatment option.^2,13-15 Adjuvant radiation therapy may be necessary following excision. Currently there is no consensus on surgical management, and standard excisional margins have not been defined.²⁶ Jones et al² concluded that complete excision with wide margins likely is curative, with decreased rates of recurrence, and better awareness of this carcinoma would lead to appropriate treatment while avoiding unnecessary diagnostic tests.²

Conclusion

We report an exceptionally unique case of early pilomatrix carcinoma with a discussion on the pathogenesis and molecular pathology of hair matrix tumors. A large cohort of patients with longer follow-up periods and better molecular characterization is essential in drawing accurate information about their prognosis, identifying molecular markers that can be used as therapeutic targets, and determining ideal management strategy.

Pilomatrix carcinoma is a rare adnexal tumor with origin from the germinative matrical cells of the hair follicle. Clinically, it presents as a solitary lesion commonly found in the head and neck region as well as the upper back. The tumors cannot be distinguished by their clinical appearance only and frequently are mistaken for cysts. Histopathologic examination provides the definitive diagnosis in most cases. These carcinomas are aggressive neoplasms with a high probability of local recurrence and distant metastasis. Assessment of the Wnt signaling pathway components such as β-catenin, lymphoid enhancer-binding factor 1 (LEF-1), and caudal-related homeobox transcription factor 2 (CDX-2) potentially can be used for diagnostic purposes and targeted therapy.

We report a rare and unique case of early pilomatrix carcinoma with intralesional melanocytes. We review the molecular pathology and pathogenesis of these carcinomas as well as the significance of early diagnosis.

Case Report

A 73-year-old man with a history of extensive sun exposure presented with a 1-cm, raised, rapidly growing, slightly irregular, purple lesion on the right forearm of 3 months’ duration with tendency to bleed. He did not have a history of skin cancers and was otherwise healthy. Excision was recommended due to the progressive and rapid growth of the lesion.

Histopathologic Findings—Gross examination revealed a 0.9×0.7-cm, raised, slightly irregular lesion located 1 mm away from the closest peripheral margin. Histologically, the lesion was a relatively circumscribed, dermal-based basaloid neoplasm with slightly ill-defined edges involving the superficial and deep dermis (Figure 1A). The neoplasm was formed predominantly of sheets of basaloid cells and small nests of ghost cells, in addition to some squamoid and transitional cells (Figure 1B). The basaloid cells exhibited severe nuclear atypia, pleomorphism, increased nuclear to cytoplasmic ratio (Figure 1C), minimal to moderate amounts of eosinophilic cytoplasm, enlarged nuclei, prominent nucleoli, and coarse chromatin pattern. Abundant mitotic activity and apoptotic bodies were present as well as focal area of central necrosis (Figure 1C). Also, melanophages and a multinucleated giant cell reaction was noted. Elastic trichrome special stain highlighted focal infiltration of the neoplastic cells into the adjacent desmoplastic stroma. Melanin stain was negative for melanin pigment within the neoplasm. Given the presence of severely atypical basaloid cells along with ghost cells indicating matrical differentiation, a diagnosis of pilomatrix carcinoma was rendered.

Immunohistochemistry—The neoplastic cells were diffusely positive for p63, CDX-2 (Figure 2A), β-catenin (Figure 2B), and CD10 (Figure 2C), and focally and weakly positive for cytokeratin (CK) 5, BerEP4 (staining the tumor periphery), androgen receptor, and CK18 (a low-molecular-weight keratin). They were negative for monoclonal carcinoembryonic antigen, epithelial membrane antigen, CK7, CK20, CD34, SOX-10, CD56, synaptophysin, and chromogranin. Cytokeratin 14 was positive in the squamoid cells but negative in the basaloid cells. SOX-10 and melanoma cocktail immunostains demonstrated few intralesional dendritic melanocytes.

Comment

Pilomatrix carcinoma is a rare malignant cutaneous adnexal neoplasm with origin from the germinative matrix of the hair bulb region of hair follicles. Pilomatrix carcinoma was first reported in 1980.^1,2 These tumors are characterized by rapid growth and aggressive behavior. Their benign counterpart, pilomatrixoma, is a slow-growing, dermal or subcutaneous tumor that rarely recurs after complete excision.

As with pilomatrixoma, pilomatrix carcinomas are asymptomatic and present as solitary dermal or subcutaneous masses^3,4 that most commonly are found in the posterior neck, upper back, and preauricular regions of middle-aged or elderly adults with male predominance.⁵ They range in size from 0.5 to 20 cm with a mean of 4 cm that is slightly larger than pilomatrixoma. Pilomatrix carcinomas predominantly are firm tumors with or without cystic components, and they exhibit a high probability of recurrence and have risk for distant metastasis.^6-15

The differential diagnosis includes epidermal cysts, pilomatrixoma, basal cell carcinoma with matrical differentiation, trichoblastoma/trichoblastic carcinoma, and trichilemmal carcinoma. Pilomatrix carcinomas frequently are mistaken for epidermal cysts on clinical examination. Such a distinction can be easily resolved by histopathologic evaluation. The more challenging differential diagnosis is with pilomatrixoma. Histologically, pilomatrixomas consist of a distinct population of cells including basaloid, squamoid, transitional, and shadow cells in variable proportions. The basaloid cells transition to shadow cells in an organized zonal fashion.¹⁶ Compared to pilomatrixomas, pilomatrix carcinomas often show predominance of the basaloid cells; marked cytologic atypia and pleomorphism; numerous mitotic figures; deep infiltrative pattern into subcutaneous fat, fascia, and skeletal muscle; stromal desmoplasia; necrosis; and neurovascular invasion (Tables 1 and 2). Furthermore, the shadow cells tend to form a small nested pattern in pilomatrix carcinoma instead of the flat sheetlike pattern usually observed in pilomatrixoma.¹⁶ Basal cell carcinoma with matrical differentiation can pose a diagnostic challenge in the differential diagnosis; basal cell carcinoma usually exhibits a peripheral palisade of the basaloid cells accompanied by retraction spaces separating the tumor from the stroma. Trichoblastoma/trichoblastic carcinoma with matrical differentiation can be distinguished by its exuberant stroma, prominent primitive hair follicles, and papillary mesenchymal bodies. Trichilemmal carcinomas are recognized by their connection to the overlying epidermis, peripheral palisading, and presence of clear cells, while pilomatrix carcinoma lacks connection to the surface epithelium.

Immunohistochemical stains have little to no role in the differential diagnosis, and morphology is the mainstay in making the diagnosis. Rarely, pilomatrix carcinoma can be confused with poorly differentiated sebaceous carcinoma and poorly differentiated squamous cell carcinoma. Although careful scrutiny of the histologic features may help identify mature sebocytes in sebaceous carcinoma, evidence of keratinization in squamous cell carcinoma and ghost cells in pilomatrix carcinoma, using a panel of immunohistochemical stains can be helpful in reaching the final diagnosis (Table 3).

The development of hair matrix tumors have been known to harbor mutations in exon 3 of the catenin beta-1 gene, CTNNB1, that encodes for β-catenin, a downstream effector in the Wnt signaling pathway responsible for differentiation, proliferation, and adhesion of epithelial stem cells.^17-21 In a study conducted by Kazakov et al,²² DNA was extracted from 86 lesions: 4 were pilomatrixomas and 1 was a pilomatrix carcinoma. A polymerase chain reaction assay revealed 8 pathogenic variants of the β-catenin gene. D32Y (CTNNB1):c.94G>T (p.Asp32Tyr) and G34R (CTNNB1):c.100G>C (p.Gly34Arg) were the mutations present in pilomatrixoma and pilomatrix carcinoma, respectively.²² In addition, there are several proteins that are part of the Wnt pathway in addition to β-catenin—LEF-1 and CDX-2.

Tumminello and Hosler²³ found that pilomatrixomas and pilomatrix carcinomas were positive for CDX-2, β-catenin, and LEF-1 by immunohistochemistry. These downstream molecules in the Wnt signaling pathway could have the potential to be used as diagnostic and prognostic markers.^2,13,15,23

Although the pathogenesis is unclear, there are 2 possible mechanisms by which pilomatrix carcinomas develop. They can either arise as de novo tumors, or it is possible that initial mutations in β-catenin result in the formation of pilomatrixomas at an early age that may undergo malignant transformation in elderly patients over time with additional mutations.²

Our case was strongly and diffusely positive for β-catenin in a nuclear and cytoplasmic pattern and CDX-2 in a nuclear pattern, supporting the role of the Wnt signaling pathway in such tumors. Furthermore, our case demonstrated the presence of few intralesional normal dendritic melanocytes, a rare finding^1,24,25 but not unexpected, as melanocytes normally are present within the hair follicle matrix.

Pilomatrix carcinomas are aggressive tumors with a high risk for local recurrence and tendency for metastasis. In a study of 13 cases of pilomatrix carcinomas, Herrmann et al¹³ found that metastasis was significantly associated with local tumor recurrence (P<.0413). They concluded that the combination of overall high local recurrence and metastatic rates of pilomatrix carcinoma as well as documented tumor-related deaths would warrant continued patient follow-up, especially for recurrent tumors.¹³ Rapid growth of a tumor, either de novo or following several months of stable size, should alert physicians to perform a diagnostic biopsy.

Management options of pilomatrix carcinoma include surgery or radiation with close follow-up. The most widely reported treatment of pilomatrix carcinoma is wide local excision with histologically confirmed clear margins. Mohs micrographic surgery is an excellent treatment option.^2,13-15 Adjuvant radiation therapy may be necessary following excision. Currently there is no consensus on surgical management, and standard excisional margins have not been defined.²⁶ Jones et al² concluded that complete excision with wide margins likely is curative, with decreased rates of recurrence, and better awareness of this carcinoma would lead to appropriate treatment while avoiding unnecessary diagnostic tests.²

Conclusion

We report an exceptionally unique case of early pilomatrix carcinoma with a discussion on the pathogenesis and molecular pathology of hair matrix tumors. A large cohort of patients with longer follow-up periods and better molecular characterization is essential in drawing accurate information about their prognosis, identifying molecular markers that can be used as therapeutic targets, and determining ideal management strategy.

Pilomatrix carcinoma is a rare adnexal tumor with origin from the germinative matrical cells of the hair follicle. Clinically, it presents as a solitary lesion commonly found in the head and neck region as well as the upper back. The tumors cannot be distinguished by their clinical appearance only and frequently are mistaken for cysts. Histopathologic examination provides the definitive diagnosis in most cases. These carcinomas are aggressive neoplasms with a high probability of local recurrence and distant metastasis. Assessment of the Wnt signaling pathway components such as β-catenin, lymphoid enhancer-binding factor 1 (LEF-1), and caudal-related homeobox transcription factor 2 (CDX-2) potentially can be used for diagnostic purposes and targeted therapy.

We report a rare and unique case of early pilomatrix carcinoma with intralesional melanocytes. We review the molecular pathology and pathogenesis of these carcinomas as well as the significance of early diagnosis.

Case Report

A 73-year-old man with a history of extensive sun exposure presented with a 1-cm, raised, rapidly growing, slightly irregular, purple lesion on the right forearm of 3 months’ duration with tendency to bleed. He did not have a history of skin cancers and was otherwise healthy. Excision was recommended due to the progressive and rapid growth of the lesion.

Histopathologic Findings—Gross examination revealed a 0.9×0.7-cm, raised, slightly irregular lesion located 1 mm away from the closest peripheral margin. Histologically, the lesion was a relatively circumscribed, dermal-based basaloid neoplasm with slightly ill-defined edges involving the superficial and deep dermis (Figure 1A). The neoplasm was formed predominantly of sheets of basaloid cells and small nests of ghost cells, in addition to some squamoid and transitional cells (Figure 1B). The basaloid cells exhibited severe nuclear atypia, pleomorphism, increased nuclear to cytoplasmic ratio (Figure 1C), minimal to moderate amounts of eosinophilic cytoplasm, enlarged nuclei, prominent nucleoli, and coarse chromatin pattern. Abundant mitotic activity and apoptotic bodies were present as well as focal area of central necrosis (Figure 1C). Also, melanophages and a multinucleated giant cell reaction was noted. Elastic trichrome special stain highlighted focal infiltration of the neoplastic cells into the adjacent desmoplastic stroma. Melanin stain was negative for melanin pigment within the neoplasm. Given the presence of severely atypical basaloid cells along with ghost cells indicating matrical differentiation, a diagnosis of pilomatrix carcinoma was rendered.

Immunohistochemistry—The neoplastic cells were diffusely positive for p63, CDX-2 (Figure 2A), β-catenin (Figure 2B), and CD10 (Figure 2C), and focally and weakly positive for cytokeratin (CK) 5, BerEP4 (staining the tumor periphery), androgen receptor, and CK18 (a low-molecular-weight keratin). They were negative for monoclonal carcinoembryonic antigen, epithelial membrane antigen, CK7, CK20, CD34, SOX-10, CD56, synaptophysin, and chromogranin. Cytokeratin 14 was positive in the squamoid cells but negative in the basaloid cells. SOX-10 and melanoma cocktail immunostains demonstrated few intralesional dendritic melanocytes.

Comment

Pilomatrix carcinoma is a rare malignant cutaneous adnexal neoplasm with origin from the germinative matrix of the hair bulb region of hair follicles. Pilomatrix carcinoma was first reported in 1980.^1,2 These tumors are characterized by rapid growth and aggressive behavior. Their benign counterpart, pilomatrixoma, is a slow-growing, dermal or subcutaneous tumor that rarely recurs after complete excision.

As with pilomatrixoma, pilomatrix carcinomas are asymptomatic and present as solitary dermal or subcutaneous masses^3,4 that most commonly are found in the posterior neck, upper back, and preauricular regions of middle-aged or elderly adults with male predominance.⁵ They range in size from 0.5 to 20 cm with a mean of 4 cm that is slightly larger than pilomatrixoma. Pilomatrix carcinomas predominantly are firm tumors with or without cystic components, and they exhibit a high probability of recurrence and have risk for distant metastasis.^6-15

The differential diagnosis includes epidermal cysts, pilomatrixoma, basal cell carcinoma with matrical differentiation, trichoblastoma/trichoblastic carcinoma, and trichilemmal carcinoma. Pilomatrix carcinomas frequently are mistaken for epidermal cysts on clinical examination. Such a distinction can be easily resolved by histopathologic evaluation. The more challenging differential diagnosis is with pilomatrixoma. Histologically, pilomatrixomas consist of a distinct population of cells including basaloid, squamoid, transitional, and shadow cells in variable proportions. The basaloid cells transition to shadow cells in an organized zonal fashion.¹⁶ Compared to pilomatrixomas, pilomatrix carcinomas often show predominance of the basaloid cells; marked cytologic atypia and pleomorphism; numerous mitotic figures; deep infiltrative pattern into subcutaneous fat, fascia, and skeletal muscle; stromal desmoplasia; necrosis; and neurovascular invasion (Tables 1 and 2). Furthermore, the shadow cells tend to form a small nested pattern in pilomatrix carcinoma instead of the flat sheetlike pattern usually observed in pilomatrixoma.¹⁶ Basal cell carcinoma with matrical differentiation can pose a diagnostic challenge in the differential diagnosis; basal cell carcinoma usually exhibits a peripheral palisade of the basaloid cells accompanied by retraction spaces separating the tumor from the stroma. Trichoblastoma/trichoblastic carcinoma with matrical differentiation can be distinguished by its exuberant stroma, prominent primitive hair follicles, and papillary mesenchymal bodies. Trichilemmal carcinomas are recognized by their connection to the overlying epidermis, peripheral palisading, and presence of clear cells, while pilomatrix carcinoma lacks connection to the surface epithelium.

Immunohistochemical stains have little to no role in the differential diagnosis, and morphology is the mainstay in making the diagnosis. Rarely, pilomatrix carcinoma can be confused with poorly differentiated sebaceous carcinoma and poorly differentiated squamous cell carcinoma. Although careful scrutiny of the histologic features may help identify mature sebocytes in sebaceous carcinoma, evidence of keratinization in squamous cell carcinoma and ghost cells in pilomatrix carcinoma, using a panel of immunohistochemical stains can be helpful in reaching the final diagnosis (Table 3).

The development of hair matrix tumors have been known to harbor mutations in exon 3 of the catenin beta-1 gene, CTNNB1, that encodes for β-catenin, a downstream effector in the Wnt signaling pathway responsible for differentiation, proliferation, and adhesion of epithelial stem cells.^17-21 In a study conducted by Kazakov et al,²² DNA was extracted from 86 lesions: 4 were pilomatrixomas and 1 was a pilomatrix carcinoma. A polymerase chain reaction assay revealed 8 pathogenic variants of the β-catenin gene. D32Y (CTNNB1):c.94G>T (p.Asp32Tyr) and G34R (CTNNB1):c.100G>C (p.Gly34Arg) were the mutations present in pilomatrixoma and pilomatrix carcinoma, respectively.²² In addition, there are several proteins that are part of the Wnt pathway in addition to β-catenin—LEF-1 and CDX-2.

Tumminello and Hosler²³ found that pilomatrixomas and pilomatrix carcinomas were positive for CDX-2, β-catenin, and LEF-1 by immunohistochemistry. These downstream molecules in the Wnt signaling pathway could have the potential to be used as diagnostic and prognostic markers.^2,13,15,23

Although the pathogenesis is unclear, there are 2 possible mechanisms by which pilomatrix carcinomas develop. They can either arise as de novo tumors, or it is possible that initial mutations in β-catenin result in the formation of pilomatrixomas at an early age that may undergo malignant transformation in elderly patients over time with additional mutations.²

Our case was strongly and diffusely positive for β-catenin in a nuclear and cytoplasmic pattern and CDX-2 in a nuclear pattern, supporting the role of the Wnt signaling pathway in such tumors. Furthermore, our case demonstrated the presence of few intralesional normal dendritic melanocytes, a rare finding^1,24,25 but not unexpected, as melanocytes normally are present within the hair follicle matrix.

Pilomatrix carcinomas are aggressive tumors with a high risk for local recurrence and tendency for metastasis. In a study of 13 cases of pilomatrix carcinomas, Herrmann et al¹³ found that metastasis was significantly associated with local tumor recurrence (P<.0413). They concluded that the combination of overall high local recurrence and metastatic rates of pilomatrix carcinoma as well as documented tumor-related deaths would warrant continued patient follow-up, especially for recurrent tumors.¹³ Rapid growth of a tumor, either de novo or following several months of stable size, should alert physicians to perform a diagnostic biopsy.

Management options of pilomatrix carcinoma include surgery or radiation with close follow-up. The most widely reported treatment of pilomatrix carcinoma is wide local excision with histologically confirmed clear margins. Mohs micrographic surgery is an excellent treatment option.^2,13-15 Adjuvant radiation therapy may be necessary following excision. Currently there is no consensus on surgical management, and standard excisional margins have not been defined.²⁶ Jones et al² concluded that complete excision with wide margins likely is curative, with decreased rates of recurrence, and better awareness of this carcinoma would lead to appropriate treatment while avoiding unnecessary diagnostic tests.²

Conclusion

We report an exceptionally unique case of early pilomatrix carcinoma with a discussion on the pathogenesis and molecular pathology of hair matrix tumors. A large cohort of patients with longer follow-up periods and better molecular characterization is essential in drawing accurate information about their prognosis, identifying molecular markers that can be used as therapeutic targets, and determining ideal management strategy.

The term tanorexia describes compulsive use of a tanning bed, a disorder often identified in White patients. This compulsion is driven by underlying psychological distress that typically correlates with another psychiatric disorder, such as anxiety, body dysmorphic disorder, or an eating disorder. ¹ Severe anorexia combined with excessive indoor tanning led to a notable burden of cutaneous squamous cell carcinomas (SCCs) and keratoacanthomas in one of our patients. We discuss the management and approach to patient care in this difficult situation, which we have coined TANS syndrome (for T anorexia, A norexia, and N onmelanoma s kin cancer).

A Patient With TANS Syndrome

A 35-year-old cachectic woman, who appeared much older than her chronologic age, presented for management of numerous painful bleeding skin lesions. Diffuse, erythematous, tender nodules with central keratotic cores, some several centimeters in diameter, were scattered on the abdomen, chest, and extremities (Figure 1); similar lesions were noted on the neck (Figure 2). Numerous erythematous scaly papules and plaques consistent with actinic keratoses were noted throughout the body.

The patient reported that the cutaneous SCCs presented over the last few years, whereas her eating disorder began in adolescence and persisted despite multiple intensive outpatient and inpatient programs. The patient adamantly refused repeat hospitalization, against repeated suggestions by health care providers and her family. Comorbidities related to her anorexia included severe renal insufficiency, iron deficiency anemia, hypertriglyceridemia, kwashiorkor, and pellagra.

Within the last year, the patient had several biopsies showing SCC, keratoacanthoma type. The largest tumors had been treated by Mohs micrographic surgery, excision, and electrodesiccation or curettage. Adjuvant therapy over the last 2 years consisted of tazarotene cream 0.1%, imiquimod cream 5%, oral nicotinamide 500 mg twice daily, and acitretin 10 to 20 mg daily. Human papillomavirus 9-valent vaccine, recombinant, also had been tried as a chemopreventive and treatment, based on a published report of 2 patients in whom keratinocytic carcinomas decreased after such vaccination.² The dose of acitretin was kept low because of the patient’s severe renal insufficiency and lack of supporting data for its use in this setting. Despite these modalities, our patient continued to develop new cutaneous SCCs.

We considered starting intralesional methotrexate but deferred this course of action, given the patient’s deteriorating renal function. Our plan was to initiate intralesional 5-fluorouracil; however, the patient was admitted to the hospital and subsequently died due to cardiovascular complications of anorexia.

UV Radiation in the Setting of Immune Compromise

Habitual tanning bed use has been recognized as a psychologic addiction.^3,4 After exposure to UV radiation, damaged DNA upregulates pro-opiomelanocortin, which posttranslationally generates β-endorphins to elevate mood.^3,5

Tanning beds deliver a higher dose of UVA radiation than UVB radiation and cause darkening of pigmentation by oxidation of preformed melanin and redistribution of melanosomes.³ UVA radiation (320–400 nm) emitted from a tanning bed is 10- to 15-times higher than the radiation emitted by the midday sun and causes DNA damage through generation of reactive oxygen species. UVA penetrates the dermis; its harmful effect on DNA contributes to the pathogenesis of melanoma.

UVB radiation (290–320 nm) is mainly restricted to the epidermis and is largely responsible for erythema of the skin. UVB specifically causes direct damage to DNA by forming pyrimidine dimers, superficially causing sunburn. Excessive exposure to UVB radiation increases the risk for nonmelanoma skin cancer.⁶

Severe starvation and chronic malnutrition, as seen in anorexia nervosa, also are known to lead to immunosuppression.⁷ Exposure to UV radiation has been shown to impair the function of antigen-presenting cells, cytokines, and suppressor T cells, and is classified as a Group 1 carcinogen by the World Health Organization.^3,8 Combining a compromised immune system in anorexia with DNA damage from frequent indoor tanning provides a dangerous milieu for carcinogenesis.⁸ Without immune surveillance, as occurs with adequate nutrition, treatment of cutaneous SCC is, at best, challenging.

Primary care physicians, dermatologists, psychiatrists, nutritionists, and public health officials should educate high-risk patients to prevent TANS syndrome.

The term tanorexia describes compulsive use of a tanning bed, a disorder often identified in White patients. This compulsion is driven by underlying psychological distress that typically correlates with another psychiatric disorder, such as anxiety, body dysmorphic disorder, or an eating disorder. ¹ Severe anorexia combined with excessive indoor tanning led to a notable burden of cutaneous squamous cell carcinomas (SCCs) and keratoacanthomas in one of our patients. We discuss the management and approach to patient care in this difficult situation, which we have coined TANS syndrome (for T anorexia, A norexia, and N onmelanoma s kin cancer).

A Patient With TANS Syndrome

A 35-year-old cachectic woman, who appeared much older than her chronologic age, presented for management of numerous painful bleeding skin lesions. Diffuse, erythematous, tender nodules with central keratotic cores, some several centimeters in diameter, were scattered on the abdomen, chest, and extremities (Figure 1); similar lesions were noted on the neck (Figure 2). Numerous erythematous scaly papules and plaques consistent with actinic keratoses were noted throughout the body.

The patient reported that the cutaneous SCCs presented over the last few years, whereas her eating disorder began in adolescence and persisted despite multiple intensive outpatient and inpatient programs. The patient adamantly refused repeat hospitalization, against repeated suggestions by health care providers and her family. Comorbidities related to her anorexia included severe renal insufficiency, iron deficiency anemia, hypertriglyceridemia, kwashiorkor, and pellagra.

Within the last year, the patient had several biopsies showing SCC, keratoacanthoma type. The largest tumors had been treated by Mohs micrographic surgery, excision, and electrodesiccation or curettage. Adjuvant therapy over the last 2 years consisted of tazarotene cream 0.1%, imiquimod cream 5%, oral nicotinamide 500 mg twice daily, and acitretin 10 to 20 mg daily. Human papillomavirus 9-valent vaccine, recombinant, also had been tried as a chemopreventive and treatment, based on a published report of 2 patients in whom keratinocytic carcinomas decreased after such vaccination.² The dose of acitretin was kept low because of the patient’s severe renal insufficiency and lack of supporting data for its use in this setting. Despite these modalities, our patient continued to develop new cutaneous SCCs.

We considered starting intralesional methotrexate but deferred this course of action, given the patient’s deteriorating renal function. Our plan was to initiate intralesional 5-fluorouracil; however, the patient was admitted to the hospital and subsequently died due to cardiovascular complications of anorexia.

UV Radiation in the Setting of Immune Compromise

Habitual tanning bed use has been recognized as a psychologic addiction.^3,4 After exposure to UV radiation, damaged DNA upregulates pro-opiomelanocortin, which posttranslationally generates β-endorphins to elevate mood.^3,5

Tanning beds deliver a higher dose of UVA radiation than UVB radiation and cause darkening of pigmentation by oxidation of preformed melanin and redistribution of melanosomes.³ UVA radiation (320–400 nm) emitted from a tanning bed is 10- to 15-times higher than the radiation emitted by the midday sun and causes DNA damage through generation of reactive oxygen species. UVA penetrates the dermis; its harmful effect on DNA contributes to the pathogenesis of melanoma.

UVB radiation (290–320 nm) is mainly restricted to the epidermis and is largely responsible for erythema of the skin. UVB specifically causes direct damage to DNA by forming pyrimidine dimers, superficially causing sunburn. Excessive exposure to UVB radiation increases the risk for nonmelanoma skin cancer.⁶

Severe starvation and chronic malnutrition, as seen in anorexia nervosa, also are known to lead to immunosuppression.⁷ Exposure to UV radiation has been shown to impair the function of antigen-presenting cells, cytokines, and suppressor T cells, and is classified as a Group 1 carcinogen by the World Health Organization.^3,8 Combining a compromised immune system in anorexia with DNA damage from frequent indoor tanning provides a dangerous milieu for carcinogenesis.⁸ Without immune surveillance, as occurs with adequate nutrition, treatment of cutaneous SCC is, at best, challenging.

Primary care physicians, dermatologists, psychiatrists, nutritionists, and public health officials should educate high-risk patients to prevent TANS syndrome.

The term tanorexia describes compulsive use of a tanning bed, a disorder often identified in White patients. This compulsion is driven by underlying psychological distress that typically correlates with another psychiatric disorder, such as anxiety, body dysmorphic disorder, or an eating disorder. ¹ Severe anorexia combined with excessive indoor tanning led to a notable burden of cutaneous squamous cell carcinomas (SCCs) and keratoacanthomas in one of our patients. We discuss the management and approach to patient care in this difficult situation, which we have coined TANS syndrome (for T anorexia, A norexia, and N onmelanoma s kin cancer).

A Patient With TANS Syndrome

A 35-year-old cachectic woman, who appeared much older than her chronologic age, presented for management of numerous painful bleeding skin lesions. Diffuse, erythematous, tender nodules with central keratotic cores, some several centimeters in diameter, were scattered on the abdomen, chest, and extremities (Figure 1); similar lesions were noted on the neck (Figure 2). Numerous erythematous scaly papules and plaques consistent with actinic keratoses were noted throughout the body.

The patient reported that the cutaneous SCCs presented over the last few years, whereas her eating disorder began in adolescence and persisted despite multiple intensive outpatient and inpatient programs. The patient adamantly refused repeat hospitalization, against repeated suggestions by health care providers and her family. Comorbidities related to her anorexia included severe renal insufficiency, iron deficiency anemia, hypertriglyceridemia, kwashiorkor, and pellagra.

Within the last year, the patient had several biopsies showing SCC, keratoacanthoma type. The largest tumors had been treated by Mohs micrographic surgery, excision, and electrodesiccation or curettage. Adjuvant therapy over the last 2 years consisted of tazarotene cream 0.1%, imiquimod cream 5%, oral nicotinamide 500 mg twice daily, and acitretin 10 to 20 mg daily. Human papillomavirus 9-valent vaccine, recombinant, also had been tried as a chemopreventive and treatment, based on a published report of 2 patients in whom keratinocytic carcinomas decreased after such vaccination.² The dose of acitretin was kept low because of the patient’s severe renal insufficiency and lack of supporting data for its use in this setting. Despite these modalities, our patient continued to develop new cutaneous SCCs.

We considered starting intralesional methotrexate but deferred this course of action, given the patient’s deteriorating renal function. Our plan was to initiate intralesional 5-fluorouracil; however, the patient was admitted to the hospital and subsequently died due to cardiovascular complications of anorexia.

UV Radiation in the Setting of Immune Compromise

Habitual tanning bed use has been recognized as a psychologic addiction.^3,4 After exposure to UV radiation, damaged DNA upregulates pro-opiomelanocortin, which posttranslationally generates β-endorphins to elevate mood.^3,5

Tanning beds deliver a higher dose of UVA radiation than UVB radiation and cause darkening of pigmentation by oxidation of preformed melanin and redistribution of melanosomes.³ UVA radiation (320–400 nm) emitted from a tanning bed is 10- to 15-times higher than the radiation emitted by the midday sun and causes DNA damage through generation of reactive oxygen species. UVA penetrates the dermis; its harmful effect on DNA contributes to the pathogenesis of melanoma.

UVB radiation (290–320 nm) is mainly restricted to the epidermis and is largely responsible for erythema of the skin. UVB specifically causes direct damage to DNA by forming pyrimidine dimers, superficially causing sunburn. Excessive exposure to UVB radiation increases the risk for nonmelanoma skin cancer.⁶

Severe starvation and chronic malnutrition, as seen in anorexia nervosa, also are known to lead to immunosuppression.⁷ Exposure to UV radiation has been shown to impair the function of antigen-presenting cells, cytokines, and suppressor T cells, and is classified as a Group 1 carcinogen by the World Health Organization.^3,8 Combining a compromised immune system in anorexia with DNA damage from frequent indoor tanning provides a dangerous milieu for carcinogenesis.⁸ Without immune surveillance, as occurs with adequate nutrition, treatment of cutaneous SCC is, at best, challenging.

Primary care physicians, dermatologists, psychiatrists, nutritionists, and public health officials should educate high-risk patients to prevent TANS syndrome.

The number of same-day discharges has grown with the increase in robotic-assisted surgeries and advances in imaging and pressures to reduce hospital costs. COVID-19 has, perhaps temporarily, increased the same-day surgery numbers as surgeries have been restricted and hospital beds are needed for COVID-19 patients.

Urologist Ronney Abaza, MD, a robotic surgery specialist in Dublin, Ohio, and colleagues, reviewed robotic surgeries at their hospital during COVID-19 restrictions on surgery in Ohio between March 17 and June 5, 2020, and compared them with robotic procedures before COVID-19 and after restrictions were lifted. They published their results in Urology.

Since 2016, the hospital has offered the option of same-day discharge (SDD) to all robotic urologic surgery patients, regardless of procedure or patient-specific factors.

Among patients who had surgery during COVID-19 restrictions, 98% (87/89 patients) opted for SDD versus 52% in the group having surgery before the restrictions (P < .00001). After the COVID-19 surgery restrictions were lifted, the higher rate of SDD remained at 98%.

“There were no differences in 30-day complications or readmissions between SDD and overnight patients,” the authors write.
 

The right patient, the right motivation for successful surgery

Brian Lane, MD, PhD, a urologic oncologist with Spectrum Health in Grand Rapids, Michigan, told this news organization that, for nephrectomies, uptake of same-day discharge will continue to be slow.

“You have to have the right patient, the right patient motivation, and the surgery has to go smoothly,” he said. “If you start sending everyone home the same day, you will certainly see readmissions,” he said.

Dr. Lane is part of the Michigan Urologic Surgery Improvement Collaborative and he said the group recently looked at same-day discharge outcomes after robotic prostatectomies with SDD as compared with 1-2 nights in the hospital.

The work has not yet been published but, “There was a slight signal that there were increased readmissions with same-day discharge vs. 0-1 day,” he said.

A paper on outcomes of same-day discharge in total knee arthroplasty in the Journal of Bone & Joint Surgery found a higher risk of perioperative complications “including component failure, surgical site infection, knee stiffness, and deep vein thrombosis.” Researchers compared outcomes between 4,391 patients who underwent outpatient TKA and 128,951 patients who underwent inpatient TKA.

But for other many surgeries, same-day discharge numbers are increasing without worsening outcomes.

A paper in the Journal of Robotic Surgery found that same-day discharge following robotic-assisted endometrial cancer staging is “safe and feasible.”

Stephen Bradley, MD, MPH, with the Minneapolis Heart Institute in Minneapolis, and colleagues write in the Journal of the American College of Cardiology: Cardiovascular Interventions that they found a large increase in the use of same-day discharge after elective percutaneous coronary intervention (PCI) was not associated with worse 30-day mortality rates or readmission.

In that study, 114,461 patients were discharged the same day they underwent PCI. The proportion of patients who had a same-day discharge increased from 4.5% in 2009 to 28.6% in the fourth quarter of 2017.

Risk-adjusted 30-day mortality did not change in that time, while risk-adjusted rehospitalization decreased over time and more quickly when patients had same-day discharge.

Deepak L. Bhatt, MD, MPH, and Jonathan G. Sung, MBCHB, both of Brigham and Women’s Hospital Heart & Vascular Center, Harvard Medical School, Boston, wrote in an accompanying article that, “Advances in the devices and techniques of PCI have improved the safety and efficacy of the procedure. In selected patients, same-day discharge has become possible, and overnight in-hospital observation can be avoided. By reducing unnecessary hospital stays, both patients and hospitals could benefit.”

Evan Garden, a medical student at Icahn School of Medicine at Mount Sinai in New York, presented findings at the American Urological Association 2021 annual meeting that show patients selected for same-day discharge after partial or radical nephrectomy did not have increased rates of postoperative complications or readmissions in the immediate postoperative period, compared with standard discharge of 1-3 days.
 

Case studies in nephrectomy

While several case studies have looked at the feasibility and safety of performing partial and radical nephrectomy with same-day discharge in select cases, “this topic has not been addressed on a national level,” Mr. Garden said.

Few patients who have partial or radical nephrectomies have same-day discharges. The researchers found that fewer than 1% of patients who have either procedure in the sample studied were discharged the same day.

Researchers used the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database, a nationally representative deidentified database that prospectively tracks patient characteristics and 30-day perioperative outcomes for major inpatient and outpatient surgical procedures at more than 700 hospitals.

They extracted all minimally invasive partial and radical nephrectomies from 2012 to 2019 and refined the cohort to 28,140 patients who were theoretically eligible for same-day discharge: Of those, 237 (0.8%) had SSD, and 27,903 (99.2%) had a standard-length discharge (SLD).

The team found that there were no differences in 30-day complications or readmissions between same-day discharge (Clavien-Dindo [CD] I/II, 4.22%; CD III, 0%; CD IV, 1.27%; readmission, 4.64%); and SLD (CD I/II, 4.11%; CD III, 0.95%; CD IV, 0.79%; readmission, 3.90%; all P > .05).

Controlling for demographic and clinical variables, SDD was not associated with greater risk of 30-day complications or readmissions (CD I/II: odds ratio, 1.08; 95% confidence interval, 0.57-2.048; P = .813; CD IV: OR 1.699; 95% CI, 0.537-5.375; P = .367; readmission: OR, 1.254; 95% CI, 0.681-2.31; P = .467).

Mr. Garden and coauthors report no relevant financial relationships.

Dr. Lane reports no relevant financial relationships.

The number of same-day discharges has grown with the increase in robotic-assisted surgeries and advances in imaging and pressures to reduce hospital costs. COVID-19 has, perhaps temporarily, increased the same-day surgery numbers as surgeries have been restricted and hospital beds are needed for COVID-19 patients.

Urologist Ronney Abaza, MD, a robotic surgery specialist in Dublin, Ohio, and colleagues, reviewed robotic surgeries at their hospital during COVID-19 restrictions on surgery in Ohio between March 17 and June 5, 2020, and compared them with robotic procedures before COVID-19 and after restrictions were lifted. They published their results in Urology.

Since 2016, the hospital has offered the option of same-day discharge (SDD) to all robotic urologic surgery patients, regardless of procedure or patient-specific factors.

Among patients who had surgery during COVID-19 restrictions, 98% (87/89 patients) opted for SDD versus 52% in the group having surgery before the restrictions (P < .00001). After the COVID-19 surgery restrictions were lifted, the higher rate of SDD remained at 98%.

“There were no differences in 30-day complications or readmissions between SDD and overnight patients,” the authors write.
 

The right patient, the right motivation for successful surgery

Brian Lane, MD, PhD, a urologic oncologist with Spectrum Health in Grand Rapids, Michigan, told this news organization that, for nephrectomies, uptake of same-day discharge will continue to be slow.

“You have to have the right patient, the right patient motivation, and the surgery has to go smoothly,” he said. “If you start sending everyone home the same day, you will certainly see readmissions,” he said.

Dr. Lane is part of the Michigan Urologic Surgery Improvement Collaborative and he said the group recently looked at same-day discharge outcomes after robotic prostatectomies with SDD as compared with 1-2 nights in the hospital.

The work has not yet been published but, “There was a slight signal that there were increased readmissions with same-day discharge vs. 0-1 day,” he said.

A paper on outcomes of same-day discharge in total knee arthroplasty in the Journal of Bone & Joint Surgery found a higher risk of perioperative complications “including component failure, surgical site infection, knee stiffness, and deep vein thrombosis.” Researchers compared outcomes between 4,391 patients who underwent outpatient TKA and 128,951 patients who underwent inpatient TKA.

But for other many surgeries, same-day discharge numbers are increasing without worsening outcomes.

A paper in the Journal of Robotic Surgery found that same-day discharge following robotic-assisted endometrial cancer staging is “safe and feasible.”

Stephen Bradley, MD, MPH, with the Minneapolis Heart Institute in Minneapolis, and colleagues write in the Journal of the American College of Cardiology: Cardiovascular Interventions that they found a large increase in the use of same-day discharge after elective percutaneous coronary intervention (PCI) was not associated with worse 30-day mortality rates or readmission.

In that study, 114,461 patients were discharged the same day they underwent PCI. The proportion of patients who had a same-day discharge increased from 4.5% in 2009 to 28.6% in the fourth quarter of 2017.

Risk-adjusted 30-day mortality did not change in that time, while risk-adjusted rehospitalization decreased over time and more quickly when patients had same-day discharge.

Deepak L. Bhatt, MD, MPH, and Jonathan G. Sung, MBCHB, both of Brigham and Women’s Hospital Heart & Vascular Center, Harvard Medical School, Boston, wrote in an accompanying article that, “Advances in the devices and techniques of PCI have improved the safety and efficacy of the procedure. In selected patients, same-day discharge has become possible, and overnight in-hospital observation can be avoided. By reducing unnecessary hospital stays, both patients and hospitals could benefit.”

Evan Garden, a medical student at Icahn School of Medicine at Mount Sinai in New York, presented findings at the American Urological Association 2021 annual meeting that show patients selected for same-day discharge after partial or radical nephrectomy did not have increased rates of postoperative complications or readmissions in the immediate postoperative period, compared with standard discharge of 1-3 days.
 

Case studies in nephrectomy

While several case studies have looked at the feasibility and safety of performing partial and radical nephrectomy with same-day discharge in select cases, “this topic has not been addressed on a national level,” Mr. Garden said.

Few patients who have partial or radical nephrectomies have same-day discharges. The researchers found that fewer than 1% of patients who have either procedure in the sample studied were discharged the same day.

Researchers used the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database, a nationally representative deidentified database that prospectively tracks patient characteristics and 30-day perioperative outcomes for major inpatient and outpatient surgical procedures at more than 700 hospitals.

They extracted all minimally invasive partial and radical nephrectomies from 2012 to 2019 and refined the cohort to 28,140 patients who were theoretically eligible for same-day discharge: Of those, 237 (0.8%) had SSD, and 27,903 (99.2%) had a standard-length discharge (SLD).

The team found that there were no differences in 30-day complications or readmissions between same-day discharge (Clavien-Dindo [CD] I/II, 4.22%; CD III, 0%; CD IV, 1.27%; readmission, 4.64%); and SLD (CD I/II, 4.11%; CD III, 0.95%; CD IV, 0.79%; readmission, 3.90%; all P > .05).

Controlling for demographic and clinical variables, SDD was not associated with greater risk of 30-day complications or readmissions (CD I/II: odds ratio, 1.08; 95% confidence interval, 0.57-2.048; P = .813; CD IV: OR 1.699; 95% CI, 0.537-5.375; P = .367; readmission: OR, 1.254; 95% CI, 0.681-2.31; P = .467).

Mr. Garden and coauthors report no relevant financial relationships.

Dr. Lane reports no relevant financial relationships.

The number of same-day discharges has grown with the increase in robotic-assisted surgeries and advances in imaging and pressures to reduce hospital costs. COVID-19 has, perhaps temporarily, increased the same-day surgery numbers as surgeries have been restricted and hospital beds are needed for COVID-19 patients.

Urologist Ronney Abaza, MD, a robotic surgery specialist in Dublin, Ohio, and colleagues, reviewed robotic surgeries at their hospital during COVID-19 restrictions on surgery in Ohio between March 17 and June 5, 2020, and compared them with robotic procedures before COVID-19 and after restrictions were lifted. They published their results in Urology.

Since 2016, the hospital has offered the option of same-day discharge (SDD) to all robotic urologic surgery patients, regardless of procedure or patient-specific factors.

Among patients who had surgery during COVID-19 restrictions, 98% (87/89 patients) opted for SDD versus 52% in the group having surgery before the restrictions (P < .00001). After the COVID-19 surgery restrictions were lifted, the higher rate of SDD remained at 98%.

“There were no differences in 30-day complications or readmissions between SDD and overnight patients,” the authors write.
 

The right patient, the right motivation for successful surgery

Brian Lane, MD, PhD, a urologic oncologist with Spectrum Health in Grand Rapids, Michigan, told this news organization that, for nephrectomies, uptake of same-day discharge will continue to be slow.

“You have to have the right patient, the right patient motivation, and the surgery has to go smoothly,” he said. “If you start sending everyone home the same day, you will certainly see readmissions,” he said.

Dr. Lane is part of the Michigan Urologic Surgery Improvement Collaborative and he said the group recently looked at same-day discharge outcomes after robotic prostatectomies with SDD as compared with 1-2 nights in the hospital.

The work has not yet been published but, “There was a slight signal that there were increased readmissions with same-day discharge vs. 0-1 day,” he said.

A paper on outcomes of same-day discharge in total knee arthroplasty in the Journal of Bone & Joint Surgery found a higher risk of perioperative complications “including component failure, surgical site infection, knee stiffness, and deep vein thrombosis.” Researchers compared outcomes between 4,391 patients who underwent outpatient TKA and 128,951 patients who underwent inpatient TKA.

But for other many surgeries, same-day discharge numbers are increasing without worsening outcomes.

A paper in the Journal of Robotic Surgery found that same-day discharge following robotic-assisted endometrial cancer staging is “safe and feasible.”

Stephen Bradley, MD, MPH, with the Minneapolis Heart Institute in Minneapolis, and colleagues write in the Journal of the American College of Cardiology: Cardiovascular Interventions that they found a large increase in the use of same-day discharge after elective percutaneous coronary intervention (PCI) was not associated with worse 30-day mortality rates or readmission.

In that study, 114,461 patients were discharged the same day they underwent PCI. The proportion of patients who had a same-day discharge increased from 4.5% in 2009 to 28.6% in the fourth quarter of 2017.

Risk-adjusted 30-day mortality did not change in that time, while risk-adjusted rehospitalization decreased over time and more quickly when patients had same-day discharge.

Deepak L. Bhatt, MD, MPH, and Jonathan G. Sung, MBCHB, both of Brigham and Women’s Hospital Heart & Vascular Center, Harvard Medical School, Boston, wrote in an accompanying article that, “Advances in the devices and techniques of PCI have improved the safety and efficacy of the procedure. In selected patients, same-day discharge has become possible, and overnight in-hospital observation can be avoided. By reducing unnecessary hospital stays, both patients and hospitals could benefit.”

Evan Garden, a medical student at Icahn School of Medicine at Mount Sinai in New York, presented findings at the American Urological Association 2021 annual meeting that show patients selected for same-day discharge after partial or radical nephrectomy did not have increased rates of postoperative complications or readmissions in the immediate postoperative period, compared with standard discharge of 1-3 days.
 

Case studies in nephrectomy

While several case studies have looked at the feasibility and safety of performing partial and radical nephrectomy with same-day discharge in select cases, “this topic has not been addressed on a national level,” Mr. Garden said.

Few patients who have partial or radical nephrectomies have same-day discharges. The researchers found that fewer than 1% of patients who have either procedure in the sample studied were discharged the same day.

Researchers used the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database, a nationally representative deidentified database that prospectively tracks patient characteristics and 30-day perioperative outcomes for major inpatient and outpatient surgical procedures at more than 700 hospitals.

They extracted all minimally invasive partial and radical nephrectomies from 2012 to 2019 and refined the cohort to 28,140 patients who were theoretically eligible for same-day discharge: Of those, 237 (0.8%) had SSD, and 27,903 (99.2%) had a standard-length discharge (SLD).

The team found that there were no differences in 30-day complications or readmissions between same-day discharge (Clavien-Dindo [CD] I/II, 4.22%; CD III, 0%; CD IV, 1.27%; readmission, 4.64%); and SLD (CD I/II, 4.11%; CD III, 0.95%; CD IV, 0.79%; readmission, 3.90%; all P > .05).

Controlling for demographic and clinical variables, SDD was not associated with greater risk of 30-day complications or readmissions (CD I/II: odds ratio, 1.08; 95% confidence interval, 0.57-2.048; P = .813; CD IV: OR 1.699; 95% CI, 0.537-5.375; P = .367; readmission: OR, 1.254; 95% CI, 0.681-2.31; P = .467).

Mr. Garden and coauthors report no relevant financial relationships.

Dr. Lane reports no relevant financial relationships.