Nonmelanoma Skin Cancer

In another sign that immune-suppressing drugs may cause skin cancer, a new Irish study links immunomodulator use in younger patients with inflammatory bowel disease (IBD) to higher rates of nonmelanoma skin cancer (NMSC).

The 19-year study lacks information about medication doses or duration, and it doesn’t confirm a cause-and-effect link. Still, researchers recommend that all patients with IBD be urged to comply with skin cancer prevention guidelines.

As the study notes, previous research has linked immunosuppression – such as that in transplant patients and those with AIDS and lymphoma – to higher rates of NMSC.

Studies have also linked IBD to higher rates of NMSC even before the age of 50, possibly as the result of immune system dysfunction and exposure to immunomodulators, especially thiopurines. The risk of tumor necrosis factor–alpha (TNF-alpha) inhibitors, the study says, is less clear.

To better understand the risk of immunomodulators, researchers led by Julianne Clowry, MBBCh, of St Vincent’s University Hospital in Dublin tracked 2,053 IBD patients at a tertiary adult hospital from 1994 to 2013.

The median age at IBD diagnosis was 31 with a median of 19.6 years of illness, and the patients had both Crohn’s disease (41%) and ulcerative colitis (59%). Fifty-seven percent of patients had taken immunomodulating medication, although the database used didn’t disclose details about dose or duration, and 43% had not.

The study findings appeared Jan. 3 in the Journal of the European Academy of Dermatology and Venereology (doi: 10.1111/jdv.14105).

NMSC was diagnosed in 1.7% of the entire cohort, 1.4% of patients who’d taken immunosuppressants, and 1.9% of those who had not.

Older ages may explain the higher rate in those who didn’t take the medications. The researchers found that the standardized incidence ratio for the patients who took immunomodulators overall was 1.76 [confidence interval, 1.0-2.7], compared with a matched general population cohort, while the ratio was not considered significant among the nonimmunosuppressed [1.07; CI, 0.6-1.6].

The study links use of thiopurines alone and use of both thiopurines and TNF-alpha inhibitors to higher rates of NMSC [odds ratio, 5.26; 95% CI, 2.15-12.93; P less than .001, and OR: 6.45; 95% CI, 2.69-15.95; P less than .001, respectively].

The researchers note that 82% of those who had taken a TNF-alpha inhibitor also took a thiopurine at some point.

The study says the “relatively high” standardized incident ratios are worrisome amid more use of dual immunomodulators and higher IBD rates in kids and younger adults. But the medications are “vital,” the study says, and the researchers suggest “targeted dermatology referrals for IBD patients, particularly those exposed to dual immunomodulatory therapy from an early age.”

The study authors disclose no source of funding and report no relevant disclosures.

In another sign that immune-suppressing drugs may cause skin cancer, a new Irish study links immunomodulator use in younger patients with inflammatory bowel disease (IBD) to higher rates of nonmelanoma skin cancer (NMSC).

The 19-year study lacks information about medication doses or duration, and it doesn’t confirm a cause-and-effect link. Still, researchers recommend that all patients with IBD be urged to comply with skin cancer prevention guidelines.

As the study notes, previous research has linked immunosuppression – such as that in transplant patients and those with AIDS and lymphoma – to higher rates of NMSC.

Studies have also linked IBD to higher rates of NMSC even before the age of 50, possibly as the result of immune system dysfunction and exposure to immunomodulators, especially thiopurines. The risk of tumor necrosis factor–alpha (TNF-alpha) inhibitors, the study says, is less clear.

To better understand the risk of immunomodulators, researchers led by Julianne Clowry, MBBCh, of St Vincent’s University Hospital in Dublin tracked 2,053 IBD patients at a tertiary adult hospital from 1994 to 2013.

The median age at IBD diagnosis was 31 with a median of 19.6 years of illness, and the patients had both Crohn’s disease (41%) and ulcerative colitis (59%). Fifty-seven percent of patients had taken immunomodulating medication, although the database used didn’t disclose details about dose or duration, and 43% had not.

The study findings appeared Jan. 3 in the Journal of the European Academy of Dermatology and Venereology (doi: 10.1111/jdv.14105).

NMSC was diagnosed in 1.7% of the entire cohort, 1.4% of patients who’d taken immunosuppressants, and 1.9% of those who had not.

Older ages may explain the higher rate in those who didn’t take the medications. The researchers found that the standardized incidence ratio for the patients who took immunomodulators overall was 1.76 [confidence interval, 1.0-2.7], compared with a matched general population cohort, while the ratio was not considered significant among the nonimmunosuppressed [1.07; CI, 0.6-1.6].

The study links use of thiopurines alone and use of both thiopurines and TNF-alpha inhibitors to higher rates of NMSC [odds ratio, 5.26; 95% CI, 2.15-12.93; P less than .001, and OR: 6.45; 95% CI, 2.69-15.95; P less than .001, respectively].

The researchers note that 82% of those who had taken a TNF-alpha inhibitor also took a thiopurine at some point.

The study says the “relatively high” standardized incident ratios are worrisome amid more use of dual immunomodulators and higher IBD rates in kids and younger adults. But the medications are “vital,” the study says, and the researchers suggest “targeted dermatology referrals for IBD patients, particularly those exposed to dual immunomodulatory therapy from an early age.”

The study authors disclose no source of funding and report no relevant disclosures.

In another sign that immune-suppressing drugs may cause skin cancer, a new Irish study links immunomodulator use in younger patients with inflammatory bowel disease (IBD) to higher rates of nonmelanoma skin cancer (NMSC).

The 19-year study lacks information about medication doses or duration, and it doesn’t confirm a cause-and-effect link. Still, researchers recommend that all patients with IBD be urged to comply with skin cancer prevention guidelines.

As the study notes, previous research has linked immunosuppression – such as that in transplant patients and those with AIDS and lymphoma – to higher rates of NMSC.

Studies have also linked IBD to higher rates of NMSC even before the age of 50, possibly as the result of immune system dysfunction and exposure to immunomodulators, especially thiopurines. The risk of tumor necrosis factor–alpha (TNF-alpha) inhibitors, the study says, is less clear.

To better understand the risk of immunomodulators, researchers led by Julianne Clowry, MBBCh, of St Vincent’s University Hospital in Dublin tracked 2,053 IBD patients at a tertiary adult hospital from 1994 to 2013.

The median age at IBD diagnosis was 31 with a median of 19.6 years of illness, and the patients had both Crohn’s disease (41%) and ulcerative colitis (59%). Fifty-seven percent of patients had taken immunomodulating medication, although the database used didn’t disclose details about dose or duration, and 43% had not.

The study findings appeared Jan. 3 in the Journal of the European Academy of Dermatology and Venereology (doi: 10.1111/jdv.14105).

NMSC was diagnosed in 1.7% of the entire cohort, 1.4% of patients who’d taken immunosuppressants, and 1.9% of those who had not.

Older ages may explain the higher rate in those who didn’t take the medications. The researchers found that the standardized incidence ratio for the patients who took immunomodulators overall was 1.76 [confidence interval, 1.0-2.7], compared with a matched general population cohort, while the ratio was not considered significant among the nonimmunosuppressed [1.07; CI, 0.6-1.6].

The study links use of thiopurines alone and use of both thiopurines and TNF-alpha inhibitors to higher rates of NMSC [odds ratio, 5.26; 95% CI, 2.15-12.93; P less than .001, and OR: 6.45; 95% CI, 2.69-15.95; P less than .001, respectively].

The researchers note that 82% of those who had taken a TNF-alpha inhibitor also took a thiopurine at some point.

The study says the “relatively high” standardized incident ratios are worrisome amid more use of dual immunomodulators and higher IBD rates in kids and younger adults. But the medications are “vital,” the study says, and the researchers suggest “targeted dermatology referrals for IBD patients, particularly those exposed to dual immunomodulatory therapy from an early age.”

The study authors disclose no source of funding and report no relevant disclosures.

In a global survey, 88% of respondents knew that unprotected sun exposure leads to skin cancer, but less than 60% “always” or “often” applied sunscreen to their faces, arms, and legs, researchers said.

Many respondents also reported ignoring whole categories of sun-protective behaviors – such as wearing long sleeves and seeking shade – and lacked knowledge about individual risk factors for skin cancer, such as skin type and size of moles, Sophie Seite, PhD, and her coauthors reported in the Journal of the European Academy of Dermatology and Venereology. These data suggest “that messaging needs to be specifically targeted for at-risk demographics (especially by age, gender, skin type, and country),” they added.

karenfoleyphotography/Thinkstock

In a global survey, 88% of respondents knew that unprotected sun exposure leads to skin cancer, but less than 60% “always” or “often” applied sunscreen to their faces, arms, and legs, researchers said.

Many respondents also reported ignoring whole categories of sun-protective behaviors – such as wearing long sleeves and seeking shade – and lacked knowledge about individual risk factors for skin cancer, such as skin type and size of moles, Sophie Seite, PhD, and her coauthors reported in the Journal of the European Academy of Dermatology and Venereology. These data suggest “that messaging needs to be specifically targeted for at-risk demographics (especially by age, gender, skin type, and country),” they added.

karenfoleyphotography/Thinkstock

In a global survey, 88% of respondents knew that unprotected sun exposure leads to skin cancer, but less than 60% “always” or “often” applied sunscreen to their faces, arms, and legs, researchers said.

Many respondents also reported ignoring whole categories of sun-protective behaviors – such as wearing long sleeves and seeking shade – and lacked knowledge about individual risk factors for skin cancer, such as skin type and size of moles, Sophie Seite, PhD, and her coauthors reported in the Journal of the European Academy of Dermatology and Venereology. These data suggest “that messaging needs to be specifically targeted for at-risk demographics (especially by age, gender, skin type, and country),” they added.

karenfoleyphotography/Thinkstock

Metastatic Clear Cell Renal Cell Carcinoma

The differential diagnosis of cutaneous neoplasms with clear cells is broad. Clear cell features can be seen in primary tumors arising from the epidermis and cutaneous adnexa as well as in mesenchymal and melanocytic neoplasms. Furthermore, metastatic disease should be considered in the histologic differential diagnosis, as many visceral malignancies have clear cell features. This patient was subsequently found to have a large renal mass with metastasis to the lungs, spleen, and bone. The histologic findings support the diagnosis of metastatic clear cell renal cell carcinoma (RCC) to the skin.

Approximately 30% of patients with clear cell RCC present with metastatic disease with approximately 8% of those involving the skin.^1,2 Cutaneous RCC metastases show a predilection for the head, especially the scalp. The clinical presentation is variable, but there often is a history of a rapidly growing brown, black, or purple nodule or plaque. A thorough review of the patient's history should be conducted if metastatic RCC is in the differential diagnosis, as it has been reported to occur up to 20 years after initial diagnosis.³

Histologically, clear cell RCC (quiz image) is composed of nests of tumor cells with clear cytoplasm and centrally located nuclei with prominent nucleoli. The clear cell features result from abundant cytoplasmic glycogen and lipid but may not be present in every case. One of the most important histologic features is the presence of delicate branching blood vessels (Figure 1). Numerous extravasated red blood cells also may be present. Positive immunohistochemical staining for PAX8, CD10, and RCC antigens support the diagnosis.⁴

Balloon cell nevi (Figure 2) most commonly occur on the head and neck in adolescents and young adults but clinically are indistinguishable from other banal nevi. The nevus cells are large with foamy to finely vacuolated cytoplasm and lack atypia. The clear cell change is the result of melanosome degeneration and may be extensive. The presence of melanin pigment, nests of typical nevus cells, and positive staining with MART-1 can help distinguish the tumor from xanthomas and RCC.⁵

Clear cell hidradenoma (Figure 3) is a well-circumscribed tumor of sweat gland origin that arises in the dermis. The architecture usually is solid, cystic, or a combination of both. The cytology is classically bland with poroid, squamoid, or clear cell morphology. Clear cells that are positive on periodic acid-Schiff staining predominate in up to one-third of cases. Carcinoembryonic antigen and epithelial membrane antigen can be used to highlight the eosinophilic cuticles of ducts within solid areas.⁶

Sebaceous carcinoma (Figure 4) most frequently arises in a periorbital distribution, although extraocular lesions are known to occur. Histologically, there is a proliferation of both mature sebocytes and basaloid cells in the dermis, occasionally involving the epidermis. The mature sebocytes demonstrate clear cell features with foamy to vacuolated cytoplasm and large nuclei with scalloped borders. The clear cells may vary greatly in number and often are sparse in poorly differentiated tumors in which pleomorphic basaloid cells may predominate. The basaloid cells may resemble those of squamous or basal cell carcinoma, leading to a diagnostic dilemma in some cases. Special staining with Sudan black B and oil red O highlights the cytoplasmic lipid but must be performed on frozen section specimens. Although not entirely specific, immunohistochemical expression of epithelial membrane antigen, androgen receptor, and membranous vesicular adipophilin staining in sebaceous carcinoma can assist in the diagnosis.⁷

Cutaneous xanthomas (Figure 5) may arise in patients of any age and represent deposition of lipid-laden macrophages. Classification often is dependent on the clinical presentation; however, some subtypes demonstrate unique morphologic features (eg, verruciform xanthomas). Xanthomas classically arise in association with elevated serum lipids, but they also may occur in normolipemic patients. Individuals with Erdheim-Chester disease have an increased propensity to develop xanthelasma. Similarly, plane xanthomas have been associated with monoclonal gammopathy. Histologically, xanthomas are characterized by sheets of foamy macrophages within the dermis and subcutis. Positive immunohistochemical staining for CD68 highlighting the histiocytic nature of the cells and the absence of a delicate vascular network aid in the differentiation from RCC.

Metastatic Clear Cell Renal Cell Carcinoma

The differential diagnosis of cutaneous neoplasms with clear cells is broad. Clear cell features can be seen in primary tumors arising from the epidermis and cutaneous adnexa as well as in mesenchymal and melanocytic neoplasms. Furthermore, metastatic disease should be considered in the histologic differential diagnosis, as many visceral malignancies have clear cell features. This patient was subsequently found to have a large renal mass with metastasis to the lungs, spleen, and bone. The histologic findings support the diagnosis of metastatic clear cell renal cell carcinoma (RCC) to the skin.

Approximately 30% of patients with clear cell RCC present with metastatic disease with approximately 8% of those involving the skin.^1,2 Cutaneous RCC metastases show a predilection for the head, especially the scalp. The clinical presentation is variable, but there often is a history of a rapidly growing brown, black, or purple nodule or plaque. A thorough review of the patient's history should be conducted if metastatic RCC is in the differential diagnosis, as it has been reported to occur up to 20 years after initial diagnosis.³

Histologically, clear cell RCC (quiz image) is composed of nests of tumor cells with clear cytoplasm and centrally located nuclei with prominent nucleoli. The clear cell features result from abundant cytoplasmic glycogen and lipid but may not be present in every case. One of the most important histologic features is the presence of delicate branching blood vessels (Figure 1). Numerous extravasated red blood cells also may be present. Positive immunohistochemical staining for PAX8, CD10, and RCC antigens support the diagnosis.⁴

Balloon cell nevi (Figure 2) most commonly occur on the head and neck in adolescents and young adults but clinically are indistinguishable from other banal nevi. The nevus cells are large with foamy to finely vacuolated cytoplasm and lack atypia. The clear cell change is the result of melanosome degeneration and may be extensive. The presence of melanin pigment, nests of typical nevus cells, and positive staining with MART-1 can help distinguish the tumor from xanthomas and RCC.⁵

Clear cell hidradenoma (Figure 3) is a well-circumscribed tumor of sweat gland origin that arises in the dermis. The architecture usually is solid, cystic, or a combination of both. The cytology is classically bland with poroid, squamoid, or clear cell morphology. Clear cells that are positive on periodic acid-Schiff staining predominate in up to one-third of cases. Carcinoembryonic antigen and epithelial membrane antigen can be used to highlight the eosinophilic cuticles of ducts within solid areas.⁶

Sebaceous carcinoma (Figure 4) most frequently arises in a periorbital distribution, although extraocular lesions are known to occur. Histologically, there is a proliferation of both mature sebocytes and basaloid cells in the dermis, occasionally involving the epidermis. The mature sebocytes demonstrate clear cell features with foamy to vacuolated cytoplasm and large nuclei with scalloped borders. The clear cells may vary greatly in number and often are sparse in poorly differentiated tumors in which pleomorphic basaloid cells may predominate. The basaloid cells may resemble those of squamous or basal cell carcinoma, leading to a diagnostic dilemma in some cases. Special staining with Sudan black B and oil red O highlights the cytoplasmic lipid but must be performed on frozen section specimens. Although not entirely specific, immunohistochemical expression of epithelial membrane antigen, androgen receptor, and membranous vesicular adipophilin staining in sebaceous carcinoma can assist in the diagnosis.⁷

Cutaneous xanthomas (Figure 5) may arise in patients of any age and represent deposition of lipid-laden macrophages. Classification often is dependent on the clinical presentation; however, some subtypes demonstrate unique morphologic features (eg, verruciform xanthomas). Xanthomas classically arise in association with elevated serum lipids, but they also may occur in normolipemic patients. Individuals with Erdheim-Chester disease have an increased propensity to develop xanthelasma. Similarly, plane xanthomas have been associated with monoclonal gammopathy. Histologically, xanthomas are characterized by sheets of foamy macrophages within the dermis and subcutis. Positive immunohistochemical staining for CD68 highlighting the histiocytic nature of the cells and the absence of a delicate vascular network aid in the differentiation from RCC.

Metastatic Clear Cell Renal Cell Carcinoma

The differential diagnosis of cutaneous neoplasms with clear cells is broad. Clear cell features can be seen in primary tumors arising from the epidermis and cutaneous adnexa as well as in mesenchymal and melanocytic neoplasms. Furthermore, metastatic disease should be considered in the histologic differential diagnosis, as many visceral malignancies have clear cell features. This patient was subsequently found to have a large renal mass with metastasis to the lungs, spleen, and bone. The histologic findings support the diagnosis of metastatic clear cell renal cell carcinoma (RCC) to the skin.

Approximately 30% of patients with clear cell RCC present with metastatic disease with approximately 8% of those involving the skin.^1,2 Cutaneous RCC metastases show a predilection for the head, especially the scalp. The clinical presentation is variable, but there often is a history of a rapidly growing brown, black, or purple nodule or plaque. A thorough review of the patient's history should be conducted if metastatic RCC is in the differential diagnosis, as it has been reported to occur up to 20 years after initial diagnosis.³

Histologically, clear cell RCC (quiz image) is composed of nests of tumor cells with clear cytoplasm and centrally located nuclei with prominent nucleoli. The clear cell features result from abundant cytoplasmic glycogen and lipid but may not be present in every case. One of the most important histologic features is the presence of delicate branching blood vessels (Figure 1). Numerous extravasated red blood cells also may be present. Positive immunohistochemical staining for PAX8, CD10, and RCC antigens support the diagnosis.⁴

Balloon cell nevi (Figure 2) most commonly occur on the head and neck in adolescents and young adults but clinically are indistinguishable from other banal nevi. The nevus cells are large with foamy to finely vacuolated cytoplasm and lack atypia. The clear cell change is the result of melanosome degeneration and may be extensive. The presence of melanin pigment, nests of typical nevus cells, and positive staining with MART-1 can help distinguish the tumor from xanthomas and RCC.⁵

Clear cell hidradenoma (Figure 3) is a well-circumscribed tumor of sweat gland origin that arises in the dermis. The architecture usually is solid, cystic, or a combination of both. The cytology is classically bland with poroid, squamoid, or clear cell morphology. Clear cells that are positive on periodic acid-Schiff staining predominate in up to one-third of cases. Carcinoembryonic antigen and epithelial membrane antigen can be used to highlight the eosinophilic cuticles of ducts within solid areas.⁶

Sebaceous carcinoma (Figure 4) most frequently arises in a periorbital distribution, although extraocular lesions are known to occur. Histologically, there is a proliferation of both mature sebocytes and basaloid cells in the dermis, occasionally involving the epidermis. The mature sebocytes demonstrate clear cell features with foamy to vacuolated cytoplasm and large nuclei with scalloped borders. The clear cells may vary greatly in number and often are sparse in poorly differentiated tumors in which pleomorphic basaloid cells may predominate. The basaloid cells may resemble those of squamous or basal cell carcinoma, leading to a diagnostic dilemma in some cases. Special staining with Sudan black B and oil red O highlights the cytoplasmic lipid but must be performed on frozen section specimens. Although not entirely specific, immunohistochemical expression of epithelial membrane antigen, androgen receptor, and membranous vesicular adipophilin staining in sebaceous carcinoma can assist in the diagnosis.⁷

Cutaneous xanthomas (Figure 5) may arise in patients of any age and represent deposition of lipid-laden macrophages. Classification often is dependent on the clinical presentation; however, some subtypes demonstrate unique morphologic features (eg, verruciform xanthomas). Xanthomas classically arise in association with elevated serum lipids, but they also may occur in normolipemic patients. Individuals with Erdheim-Chester disease have an increased propensity to develop xanthelasma. Similarly, plane xanthomas have been associated with monoclonal gammopathy. Histologically, xanthomas are characterized by sheets of foamy macrophages within the dermis and subcutis. Positive immunohistochemical staining for CD68 highlighting the histiocytic nature of the cells and the absence of a delicate vascular network aid in the differentiation from RCC.

Basal cell carcinoma (BCC) is the most prevalent malignancy in white individuals and its incidence is rapidly increasing. Despite its low mortality rate, BCC can cause severe morbidity and remains a serious health problem with a high economic burden for health care systems. The incidence of BCC is higher in individuals who have red or blonde hair, light eye color, and/or Fitzpatrick skin types I and II. The risk for developing BCC also increases with age, and men are more frequently affected than women.^1,2 Although several factors have been implicated in the etiology of this condition, such as exposure to ionizing radiation, trauma, chemical carcinogenesis, immunosuppression, predisposing syndromes, and host factors (eg, traits that affect susceptibility to disease),^3-5 exposure to UV radiation is considered to be a major risk factor, with most BCCs presenting in sun-exposed areas of the body (eg, face, neck). Prolongate suberythrodermal UV doses, which do not burn the skin but cause erythema in the histological level, can lead to formation of pyrimidine dimers in the dermal and epidermal tissues and cause DNA mutation with potential carcinogenic effects. Due to a large number of outdoor occupations, it is likely that outdoor workers (OWs) with a history of UV exposure may develop BCCs with different features than those seen in indoor workers (IWs). However, there has been debate about the relevance of occupational UV exposure as a risk factor for BCC development.^6,7 The aim of this study was to compare the clinical and histological features of BCCs in OWs versus IWs at a referral hospital in southern Spain.

Methods

Using the electronic pathology records at a referral hospital in southern Spain, we identified medical records between May 1, 2010, and May 1, 2011, of specimens containing the term skin in the specimen box and basal cell carcinoma in the diagnosis box. We excluded patients with a history of or concomitant squamous cell carcinoma. Reexcision of incompletely excised lesions; punch, shave or incisional biopsies; and palliative excisions also were excluded. The specimens were reviewed and classified according to the differentiation pattern of BCC (ie, nodular, superficial, morpheic, micronodular). Basal cell carcinomas with mixed features were classified according to the most predominant subtype.

We also gathered information regarding the patients’ work history (ie, any job held during their lifetime with a minimum duration of 6 months). Patients were asked about the type of work and start/end dates. In patients who performed OW, we evaluated hours per day and months as well as the type of clothing worn (eg, head covering, socks/stockings during work in the summer months).

Each patient was classified as an OW or IW based on his/her stated occupation. The OWs included those who performed all or most of their work (≥6 hours per day for at least 6 months) outdoors in direct sunlight. Most patients in this group included farmers and fishermen. Indoor workers were those who performed most of their work in an indoor environment (eg, shop, factory, office, hospital, library, bank, school, laboratory). Most patients in this group included mechanics and shop assistants. A small group of individuals could not be classified as OWs or IWs and therefore were excluded from the study. Individuals with a history of exposure to ionizing radiation, chemical carcinogenesis, immunosuppression, or predisposing syndromes also were excluded.

We included variables that could be considered independent risk factors for BCC, including age, sex, eye color, natural hair color, Fitzpatrick skin type, history of sunburns, and family history. All data were collected via a personal interview performed by a single dermatologist (H.H-E.) during the follow-up with the patients conducted after obtaining all medical records and contacting eligible patients; none of the patients were lost on follow-up.

The study was approved by the hospital’s ethics committee and written consent was obtained from all recruited patients for analyzing the data acquired and accessing the relevant diagnostic documents (eg, pathology reports).

The cohorts were compared by a χ² test and Student t test, which were performed using the SPSS software version 15. Statistical significance was determined using α=.05, and all tests were 2-sided.

Results

A total of 308 patients were included in the study, comprising 178 (58%) OWs and 130 (42%) IWs. Table 1 summarizes the characteristics of each cohort with the statistical outcomes.

The mean age (SD) of the OWs was significantly higher than the IWs (75.17 [10.74] vs 69.73 [9.98] years; P<.001). The sex distribution among the 2 cohorts was significantly different (P=.002); the OW group featured a slightly higher proportion of men than women (92 [52%] vs 86 [48%]), whereas women were clearly more prevalent in the IW group than men (85 [65%] vs 45 [35%]).

No significant differences regarding eye color (blue/gray vs brown/black) between the 2 cohorts were found (P>.05). In the same way, the 2 cohorts did not show differences in the natural hair color (red/blonde vs brown/black)(P>.05).

Fitzpatrick skin type II was the most common between both cohorts (82 [46%] OWs and 75 [58%] IWs), but no statistical differences regarding the proportions of each skin type were found (P>.05).

History of sunburns (>2 episodes) was significantly different between the 2 cohorts. The incidence of second-degree sunburns in childhood was higher in IWs (P<.00001), while the incidence of second-degree sunburns in adulthood was higher in OWs (P=.002).

Most OWs had a positive family history of BCC (101 [57%]), while the majority of IWs had a negative family history of BCC (90 [69%]). This difference was statistically significant (P=.03).

Table 2 shows the distribution of anatomic sites of BCCs in OWs and IWs. The nose was the most frequently affected area in OWs (35 cases [20%]), while the cheek was the most common location (23 [18%]) in IWs. Comparison of the frequency of BCC incidence for each anatomic location revealed that only the rate for truncal BCC was significantly different; IWs had a higher incidence of truncal BCCs than OWs (P=.0035). Although the differences between groups were not statistically significant, there was a trend toward a higher incidence of BCCs on the forehead in OW (P=.06).

In both cohorts, the most prevalent histologic subtype was nodular BCC (133 [75%] OWs and 88 [68%] IWs), followed by superficial BCC (17 [10%] OWs and 27 [21%] IWs). The incidence rate of nodular BCCs was statistically different between the 2 cohorts, with OWs showing a higher incidence compared to IWs (P=.024). Regarding the superficial subtype, the opposite was observed: IWs had significantly increased risk compared to OWs (P=.05). There was a trend toward a higher incidence of morpheic BCCs in OWs than IWs, but the difference was not statistically significant (P=.07).

Comment

Skin cancer due to occupational UV exposure is more common than is generally recognized,^6,7 but occupational UV exposure as a risk factor for BCC is still an ongoing debate. In this study, we analyzed the different clinical and histological features of BCC in OWs versus IWs.

The geographic area where this study was performed is characterized by a subtropical Mediterranean climate with irregular rainfall; a short, cool to mild winter; and long, dry, hot summers. Summer temperatures usually are hot and regularly exceed 35°C (95°F). UV index (UVI) is a measure of the amount of skin-damaging UV radiation expected to reach the earth’s surface when the sun is highest in the sky (around midday) and ranges from 1 (low risk) to 10 (maximum risk). In southern Spain, the mean UVI is approximately 6 and can reach up to 9 or sometimes 10 in the summer months. Although Fitzpatrick skin types II and III are most common, the elevated UVI indicates that the general population in southern Spain is at a high risk for developing skin cancer.

In our study the mean age of IWs was lower than OWs, which suggests that IWs may develop BCC at a younger age than OWs. This finding is consistent with studies showing that cumulative occupational UV exposure has been associated with development of BCCs in older age groups, while acute intermittent recreational sun exposure, particularly sustained in childhood and adolescence, is linked with BCC in younger patients.⁶

The role of sex as a risk factor for BCC remains unclear. Some reports show that BCC is more common in men than in women.^8-10 In our study, sex distribution was statistically significant (P=.002); there were more women in the IW cohort and more men in the OW cohort. These differences may be explained by cultural and lifestyle patterns, as women who are IWs tend to have office jobs in urban settings and wear modern fashion clothes at work and for recreation. In rural settings, women have agricultural jobs and tend to wear more traditional clothes that offer sun protection.

Positive family history has been suggested to be a constitutional risk factor for BCC development.^8,11,12 In our study, we observed that positive family history was more common in OWs, while most IWs had a negative family history. These differences were significant (P=.03), and OWs had a 2.6-fold increased likelihood of having a positive family history of BCC compared to IWs. Cultural and lifestyle patterns may partially explain this finding. In rural settings, workers tend to have the same job as their parents as a traditional way of life and therefore have similar patterns of UV exposure; in urban settings, individuals may have different jobs than their parents and therefore the pattern of UV exposure may be different. However, a genetic predisposition for developing BCC cannot be excluded. In addition, we have to consider that the information on family history of BCC in the patients was self-reported and not validated, which may limit the results.

The difference in history of second-degree sunburn in childhood was significantly higher in IWs than in OWs (P<.00001). The OW group had a significant rate of sunburns in adulthood (P=.002). The relationship between UV radiation and BCC is complex, and the patterns of sun exposure and their occurrence in different periods of lifetime (ie, childhood vs adulthood) remain controversial.¹³ The overall history of severe sunburns seems to be more important than simply the tendency to burn or tan,^14,15 and a history of sunburns in childhood and adolescence has been associated with early-onset BCC.⁶ Our findings were consistent in that the age of onset of BCCs was lower in IWs who had a history of sunburns in childhood. Basal cell carcinomas developed at older ages in OWs who had a higher incidence of sunburns in adulthood. However, we have to consider that the retrospective nature of the data collection on sunburns in childhood and adulthood was potentially limited, as the information was based on the patients’ memory. Additionally, other non-UV risk factors for BCC, such as ionizing radiation exposure, were not analyzed.

The majority of BCCs developed in sun-exposed areas of the head and neck in both cohorts, and only 35 (20%) and 28 (22%) BCCs were located on the trunk, arms, or legs in OWs and IWs, respectively. In our study, the rate of BCCs on the trunk was significantly lower in OWs than in IWs (P=.0035). Basal cell carcinomas on the trunk have been suggested to be linked to genetic susceptibility^16,17 and reduced DNA repair capacity¹⁸ rather than sun exposure. Our findings support this hypothesis and suggest that occupational sun exposure has no direct relation with truncal BCC. This outcome is consistent with the result of a case-control study conducted by Pelucchi et al¹⁹ (N=1040). The authors concluded that occupational UV exposure was not associated with truncal BCC development but with head/neck BCC, indicating that there may be different etiological mechanisms between truncal and head/neck BCC.¹⁹ In the largest BCC case series published in the literature with 13,457 specimens, the authors stated that tumors on the trunk may represent a particular variant of BCC, in which the theory of chronic versus intermittent UV exposure cannot be simply extrapolated as it is for the rest of BCC sites. Other factors such as genetic predisposition could be involved in the development of truncal BCC.²⁰ Similarly, Ramos et al²¹ suggested that nonmelanoma skin cancers in sun-protected anatomic sites may occur in individuals with impairment in the DNA repair process.

The classification of histological subtypes of BCC helps to predict tumor behavior,²² which can impact the prognosis. In our study, nodular BCC was the most common subtype in both cohorts, followed by superficial BCC. The nodular subtype was increased in OWs compared to IWs, while the superficial subtype was most common in IWs. Bastiaens et al²³ and McCormack et al²⁴ have suggested that the most frequent subtypes of BCC (nodular and superficial) may represent different tumors with distinct causal factors. According to these authors, nodular subtypes are associated with cumulative UV exposure, while superficial subtypes are associated with more intense and intermittent UV exposure. The results of the current study support this hypothesis, as the OW cohort with cumulative UV exposure showed more incidence of nodular BCC than IWs, while the patients with intense and intermittent sun exposure (the IWs) showed more risk of superficial BCC.

The importance of occupational UV exposure in OWs as a risk factor for BCC is still an ongoing discussion. Our data show that occupational UV exposure may be considered an etiological factor for BCC according to histological subtype and anatomic site. Our study is limited by the retrospective nature of the data collection regarding occupation and childhood sunburns, which were based on the patients’ memory and therefore potentially biased. Data regarding family history of BCC also was self-reported and not validated. Another limiting factor was that other non-UV risk factors for BCC, such as ionizing radiation exposure, were not considered. The limited sample size also may have impacted the study results. Among the strengths of the study are the complete response rate, the similar catchment area of OWs and IWs, the common hospital setting of the 2 cohorts, and the similar attention to medical history. All patients were obtained from the practice of a single referral dermatologist and are felt to be representative of our working area. The use of a single dermatologist reduces provider-associated variability.

Conclusion

According to the results of this study, OWs are more likely to develop nodular BCCs with no increased risk for superficial BCCs. The age of onset in OWs is older than in IWs. Some anatomical sites such as the trunk are more commonly affected in IWs. Truncal BCCs may have etiological factors other than UV exposure, such as a genetic predisposition. This study is useful to occupational safety representatives and physicians to stimulate the implementation of prevention strategies for this easily preventable malignancy and may encourage further research.

Basal cell carcinoma (BCC) is the most prevalent malignancy in white individuals and its incidence is rapidly increasing. Despite its low mortality rate, BCC can cause severe morbidity and remains a serious health problem with a high economic burden for health care systems. The incidence of BCC is higher in individuals who have red or blonde hair, light eye color, and/or Fitzpatrick skin types I and II. The risk for developing BCC also increases with age, and men are more frequently affected than women.^1,2 Although several factors have been implicated in the etiology of this condition, such as exposure to ionizing radiation, trauma, chemical carcinogenesis, immunosuppression, predisposing syndromes, and host factors (eg, traits that affect susceptibility to disease),^3-5 exposure to UV radiation is considered to be a major risk factor, with most BCCs presenting in sun-exposed areas of the body (eg, face, neck). Prolongate suberythrodermal UV doses, which do not burn the skin but cause erythema in the histological level, can lead to formation of pyrimidine dimers in the dermal and epidermal tissues and cause DNA mutation with potential carcinogenic effects. Due to a large number of outdoor occupations, it is likely that outdoor workers (OWs) with a history of UV exposure may develop BCCs with different features than those seen in indoor workers (IWs). However, there has been debate about the relevance of occupational UV exposure as a risk factor for BCC development.^6,7 The aim of this study was to compare the clinical and histological features of BCCs in OWs versus IWs at a referral hospital in southern Spain.

Methods

Using the electronic pathology records at a referral hospital in southern Spain, we identified medical records between May 1, 2010, and May 1, 2011, of specimens containing the term skin in the specimen box and basal cell carcinoma in the diagnosis box. We excluded patients with a history of or concomitant squamous cell carcinoma. Reexcision of incompletely excised lesions; punch, shave or incisional biopsies; and palliative excisions also were excluded. The specimens were reviewed and classified according to the differentiation pattern of BCC (ie, nodular, superficial, morpheic, micronodular). Basal cell carcinomas with mixed features were classified according to the most predominant subtype.

We also gathered information regarding the patients’ work history (ie, any job held during their lifetime with a minimum duration of 6 months). Patients were asked about the type of work and start/end dates. In patients who performed OW, we evaluated hours per day and months as well as the type of clothing worn (eg, head covering, socks/stockings during work in the summer months).

Each patient was classified as an OW or IW based on his/her stated occupation. The OWs included those who performed all or most of their work (≥6 hours per day for at least 6 months) outdoors in direct sunlight. Most patients in this group included farmers and fishermen. Indoor workers were those who performed most of their work in an indoor environment (eg, shop, factory, office, hospital, library, bank, school, laboratory). Most patients in this group included mechanics and shop assistants. A small group of individuals could not be classified as OWs or IWs and therefore were excluded from the study. Individuals with a history of exposure to ionizing radiation, chemical carcinogenesis, immunosuppression, or predisposing syndromes also were excluded.

We included variables that could be considered independent risk factors for BCC, including age, sex, eye color, natural hair color, Fitzpatrick skin type, history of sunburns, and family history. All data were collected via a personal interview performed by a single dermatologist (H.H-E.) during the follow-up with the patients conducted after obtaining all medical records and contacting eligible patients; none of the patients were lost on follow-up.

The study was approved by the hospital’s ethics committee and written consent was obtained from all recruited patients for analyzing the data acquired and accessing the relevant diagnostic documents (eg, pathology reports).

The cohorts were compared by a χ² test and Student t test, which were performed using the SPSS software version 15. Statistical significance was determined using α=.05, and all tests were 2-sided.

Results

A total of 308 patients were included in the study, comprising 178 (58%) OWs and 130 (42%) IWs. Table 1 summarizes the characteristics of each cohort with the statistical outcomes.

The mean age (SD) of the OWs was significantly higher than the IWs (75.17 [10.74] vs 69.73 [9.98] years; P<.001). The sex distribution among the 2 cohorts was significantly different (P=.002); the OW group featured a slightly higher proportion of men than women (92 [52%] vs 86 [48%]), whereas women were clearly more prevalent in the IW group than men (85 [65%] vs 45 [35%]).

No significant differences regarding eye color (blue/gray vs brown/black) between the 2 cohorts were found (P>.05). In the same way, the 2 cohorts did not show differences in the natural hair color (red/blonde vs brown/black)(P>.05).

Fitzpatrick skin type II was the most common between both cohorts (82 [46%] OWs and 75 [58%] IWs), but no statistical differences regarding the proportions of each skin type were found (P>.05).

History of sunburns (>2 episodes) was significantly different between the 2 cohorts. The incidence of second-degree sunburns in childhood was higher in IWs (P<.00001), while the incidence of second-degree sunburns in adulthood was higher in OWs (P=.002).

Most OWs had a positive family history of BCC (101 [57%]), while the majority of IWs had a negative family history of BCC (90 [69%]). This difference was statistically significant (P=.03).

Table 2 shows the distribution of anatomic sites of BCCs in OWs and IWs. The nose was the most frequently affected area in OWs (35 cases [20%]), while the cheek was the most common location (23 [18%]) in IWs. Comparison of the frequency of BCC incidence for each anatomic location revealed that only the rate for truncal BCC was significantly different; IWs had a higher incidence of truncal BCCs than OWs (P=.0035). Although the differences between groups were not statistically significant, there was a trend toward a higher incidence of BCCs on the forehead in OW (P=.06).

In both cohorts, the most prevalent histologic subtype was nodular BCC (133 [75%] OWs and 88 [68%] IWs), followed by superficial BCC (17 [10%] OWs and 27 [21%] IWs). The incidence rate of nodular BCCs was statistically different between the 2 cohorts, with OWs showing a higher incidence compared to IWs (P=.024). Regarding the superficial subtype, the opposite was observed: IWs had significantly increased risk compared to OWs (P=.05). There was a trend toward a higher incidence of morpheic BCCs in OWs than IWs, but the difference was not statistically significant (P=.07).

Comment

Skin cancer due to occupational UV exposure is more common than is generally recognized,^6,7 but occupational UV exposure as a risk factor for BCC is still an ongoing debate. In this study, we analyzed the different clinical and histological features of BCC in OWs versus IWs.

The geographic area where this study was performed is characterized by a subtropical Mediterranean climate with irregular rainfall; a short, cool to mild winter; and long, dry, hot summers. Summer temperatures usually are hot and regularly exceed 35°C (95°F). UV index (UVI) is a measure of the amount of skin-damaging UV radiation expected to reach the earth’s surface when the sun is highest in the sky (around midday) and ranges from 1 (low risk) to 10 (maximum risk). In southern Spain, the mean UVI is approximately 6 and can reach up to 9 or sometimes 10 in the summer months. Although Fitzpatrick skin types II and III are most common, the elevated UVI indicates that the general population in southern Spain is at a high risk for developing skin cancer.

In our study the mean age of IWs was lower than OWs, which suggests that IWs may develop BCC at a younger age than OWs. This finding is consistent with studies showing that cumulative occupational UV exposure has been associated with development of BCCs in older age groups, while acute intermittent recreational sun exposure, particularly sustained in childhood and adolescence, is linked with BCC in younger patients.⁶

The role of sex as a risk factor for BCC remains unclear. Some reports show that BCC is more common in men than in women.^8-10 In our study, sex distribution was statistically significant (P=.002); there were more women in the IW cohort and more men in the OW cohort. These differences may be explained by cultural and lifestyle patterns, as women who are IWs tend to have office jobs in urban settings and wear modern fashion clothes at work and for recreation. In rural settings, women have agricultural jobs and tend to wear more traditional clothes that offer sun protection.

Positive family history has been suggested to be a constitutional risk factor for BCC development.^8,11,12 In our study, we observed that positive family history was more common in OWs, while most IWs had a negative family history. These differences were significant (P=.03), and OWs had a 2.6-fold increased likelihood of having a positive family history of BCC compared to IWs. Cultural and lifestyle patterns may partially explain this finding. In rural settings, workers tend to have the same job as their parents as a traditional way of life and therefore have similar patterns of UV exposure; in urban settings, individuals may have different jobs than their parents and therefore the pattern of UV exposure may be different. However, a genetic predisposition for developing BCC cannot be excluded. In addition, we have to consider that the information on family history of BCC in the patients was self-reported and not validated, which may limit the results.

The difference in history of second-degree sunburn in childhood was significantly higher in IWs than in OWs (P<.00001). The OW group had a significant rate of sunburns in adulthood (P=.002). The relationship between UV radiation and BCC is complex, and the patterns of sun exposure and their occurrence in different periods of lifetime (ie, childhood vs adulthood) remain controversial.¹³ The overall history of severe sunburns seems to be more important than simply the tendency to burn or tan,^14,15 and a history of sunburns in childhood and adolescence has been associated with early-onset BCC.⁶ Our findings were consistent in that the age of onset of BCCs was lower in IWs who had a history of sunburns in childhood. Basal cell carcinomas developed at older ages in OWs who had a higher incidence of sunburns in adulthood. However, we have to consider that the retrospective nature of the data collection on sunburns in childhood and adulthood was potentially limited, as the information was based on the patients’ memory. Additionally, other non-UV risk factors for BCC, such as ionizing radiation exposure, were not analyzed.

The majority of BCCs developed in sun-exposed areas of the head and neck in both cohorts, and only 35 (20%) and 28 (22%) BCCs were located on the trunk, arms, or legs in OWs and IWs, respectively. In our study, the rate of BCCs on the trunk was significantly lower in OWs than in IWs (P=.0035). Basal cell carcinomas on the trunk have been suggested to be linked to genetic susceptibility^16,17 and reduced DNA repair capacity¹⁸ rather than sun exposure. Our findings support this hypothesis and suggest that occupational sun exposure has no direct relation with truncal BCC. This outcome is consistent with the result of a case-control study conducted by Pelucchi et al¹⁹ (N=1040). The authors concluded that occupational UV exposure was not associated with truncal BCC development but with head/neck BCC, indicating that there may be different etiological mechanisms between truncal and head/neck BCC.¹⁹ In the largest BCC case series published in the literature with 13,457 specimens, the authors stated that tumors on the trunk may represent a particular variant of BCC, in which the theory of chronic versus intermittent UV exposure cannot be simply extrapolated as it is for the rest of BCC sites. Other factors such as genetic predisposition could be involved in the development of truncal BCC.²⁰ Similarly, Ramos et al²¹ suggested that nonmelanoma skin cancers in sun-protected anatomic sites may occur in individuals with impairment in the DNA repair process.

The classification of histological subtypes of BCC helps to predict tumor behavior,²² which can impact the prognosis. In our study, nodular BCC was the most common subtype in both cohorts, followed by superficial BCC. The nodular subtype was increased in OWs compared to IWs, while the superficial subtype was most common in IWs. Bastiaens et al²³ and McCormack et al²⁴ have suggested that the most frequent subtypes of BCC (nodular and superficial) may represent different tumors with distinct causal factors. According to these authors, nodular subtypes are associated with cumulative UV exposure, while superficial subtypes are associated with more intense and intermittent UV exposure. The results of the current study support this hypothesis, as the OW cohort with cumulative UV exposure showed more incidence of nodular BCC than IWs, while the patients with intense and intermittent sun exposure (the IWs) showed more risk of superficial BCC.

The importance of occupational UV exposure in OWs as a risk factor for BCC is still an ongoing discussion. Our data show that occupational UV exposure may be considered an etiological factor for BCC according to histological subtype and anatomic site. Our study is limited by the retrospective nature of the data collection regarding occupation and childhood sunburns, which were based on the patients’ memory and therefore potentially biased. Data regarding family history of BCC also was self-reported and not validated. Another limiting factor was that other non-UV risk factors for BCC, such as ionizing radiation exposure, were not considered. The limited sample size also may have impacted the study results. Among the strengths of the study are the complete response rate, the similar catchment area of OWs and IWs, the common hospital setting of the 2 cohorts, and the similar attention to medical history. All patients were obtained from the practice of a single referral dermatologist and are felt to be representative of our working area. The use of a single dermatologist reduces provider-associated variability.

Conclusion

According to the results of this study, OWs are more likely to develop nodular BCCs with no increased risk for superficial BCCs. The age of onset in OWs is older than in IWs. Some anatomical sites such as the trunk are more commonly affected in IWs. Truncal BCCs may have etiological factors other than UV exposure, such as a genetic predisposition. This study is useful to occupational safety representatives and physicians to stimulate the implementation of prevention strategies for this easily preventable malignancy and may encourage further research.

Basal cell carcinoma (BCC) is the most prevalent malignancy in white individuals and its incidence is rapidly increasing. Despite its low mortality rate, BCC can cause severe morbidity and remains a serious health problem with a high economic burden for health care systems. The incidence of BCC is higher in individuals who have red or blonde hair, light eye color, and/or Fitzpatrick skin types I and II. The risk for developing BCC also increases with age, and men are more frequently affected than women.^1,2 Although several factors have been implicated in the etiology of this condition, such as exposure to ionizing radiation, trauma, chemical carcinogenesis, immunosuppression, predisposing syndromes, and host factors (eg, traits that affect susceptibility to disease),^3-5 exposure to UV radiation is considered to be a major risk factor, with most BCCs presenting in sun-exposed areas of the body (eg, face, neck). Prolongate suberythrodermal UV doses, which do not burn the skin but cause erythema in the histological level, can lead to formation of pyrimidine dimers in the dermal and epidermal tissues and cause DNA mutation with potential carcinogenic effects. Due to a large number of outdoor occupations, it is likely that outdoor workers (OWs) with a history of UV exposure may develop BCCs with different features than those seen in indoor workers (IWs). However, there has been debate about the relevance of occupational UV exposure as a risk factor for BCC development.^6,7 The aim of this study was to compare the clinical and histological features of BCCs in OWs versus IWs at a referral hospital in southern Spain.

Methods

Using the electronic pathology records at a referral hospital in southern Spain, we identified medical records between May 1, 2010, and May 1, 2011, of specimens containing the term skin in the specimen box and basal cell carcinoma in the diagnosis box. We excluded patients with a history of or concomitant squamous cell carcinoma. Reexcision of incompletely excised lesions; punch, shave or incisional biopsies; and palliative excisions also were excluded. The specimens were reviewed and classified according to the differentiation pattern of BCC (ie, nodular, superficial, morpheic, micronodular). Basal cell carcinomas with mixed features were classified according to the most predominant subtype.

We also gathered information regarding the patients’ work history (ie, any job held during their lifetime with a minimum duration of 6 months). Patients were asked about the type of work and start/end dates. In patients who performed OW, we evaluated hours per day and months as well as the type of clothing worn (eg, head covering, socks/stockings during work in the summer months).

Each patient was classified as an OW or IW based on his/her stated occupation. The OWs included those who performed all or most of their work (≥6 hours per day for at least 6 months) outdoors in direct sunlight. Most patients in this group included farmers and fishermen. Indoor workers were those who performed most of their work in an indoor environment (eg, shop, factory, office, hospital, library, bank, school, laboratory). Most patients in this group included mechanics and shop assistants. A small group of individuals could not be classified as OWs or IWs and therefore were excluded from the study. Individuals with a history of exposure to ionizing radiation, chemical carcinogenesis, immunosuppression, or predisposing syndromes also were excluded.

We included variables that could be considered independent risk factors for BCC, including age, sex, eye color, natural hair color, Fitzpatrick skin type, history of sunburns, and family history. All data were collected via a personal interview performed by a single dermatologist (H.H-E.) during the follow-up with the patients conducted after obtaining all medical records and contacting eligible patients; none of the patients were lost on follow-up.

The study was approved by the hospital’s ethics committee and written consent was obtained from all recruited patients for analyzing the data acquired and accessing the relevant diagnostic documents (eg, pathology reports).

The cohorts were compared by a χ² test and Student t test, which were performed using the SPSS software version 15. Statistical significance was determined using α=.05, and all tests were 2-sided.

Results

A total of 308 patients were included in the study, comprising 178 (58%) OWs and 130 (42%) IWs. Table 1 summarizes the characteristics of each cohort with the statistical outcomes.

The mean age (SD) of the OWs was significantly higher than the IWs (75.17 [10.74] vs 69.73 [9.98] years; P<.001). The sex distribution among the 2 cohorts was significantly different (P=.002); the OW group featured a slightly higher proportion of men than women (92 [52%] vs 86 [48%]), whereas women were clearly more prevalent in the IW group than men (85 [65%] vs 45 [35%]).

No significant differences regarding eye color (blue/gray vs brown/black) between the 2 cohorts were found (P>.05). In the same way, the 2 cohorts did not show differences in the natural hair color (red/blonde vs brown/black)(P>.05).

Fitzpatrick skin type II was the most common between both cohorts (82 [46%] OWs and 75 [58%] IWs), but no statistical differences regarding the proportions of each skin type were found (P>.05).

History of sunburns (>2 episodes) was significantly different between the 2 cohorts. The incidence of second-degree sunburns in childhood was higher in IWs (P<.00001), while the incidence of second-degree sunburns in adulthood was higher in OWs (P=.002).

Most OWs had a positive family history of BCC (101 [57%]), while the majority of IWs had a negative family history of BCC (90 [69%]). This difference was statistically significant (P=.03).

Table 2 shows the distribution of anatomic sites of BCCs in OWs and IWs. The nose was the most frequently affected area in OWs (35 cases [20%]), while the cheek was the most common location (23 [18%]) in IWs. Comparison of the frequency of BCC incidence for each anatomic location revealed that only the rate for truncal BCC was significantly different; IWs had a higher incidence of truncal BCCs than OWs (P=.0035). Although the differences between groups were not statistically significant, there was a trend toward a higher incidence of BCCs on the forehead in OW (P=.06).

In both cohorts, the most prevalent histologic subtype was nodular BCC (133 [75%] OWs and 88 [68%] IWs), followed by superficial BCC (17 [10%] OWs and 27 [21%] IWs). The incidence rate of nodular BCCs was statistically different between the 2 cohorts, with OWs showing a higher incidence compared to IWs (P=.024). Regarding the superficial subtype, the opposite was observed: IWs had significantly increased risk compared to OWs (P=.05). There was a trend toward a higher incidence of morpheic BCCs in OWs than IWs, but the difference was not statistically significant (P=.07).

Comment

Skin cancer due to occupational UV exposure is more common than is generally recognized,^6,7 but occupational UV exposure as a risk factor for BCC is still an ongoing debate. In this study, we analyzed the different clinical and histological features of BCC in OWs versus IWs.

The geographic area where this study was performed is characterized by a subtropical Mediterranean climate with irregular rainfall; a short, cool to mild winter; and long, dry, hot summers. Summer temperatures usually are hot and regularly exceed 35°C (95°F). UV index (UVI) is a measure of the amount of skin-damaging UV radiation expected to reach the earth’s surface when the sun is highest in the sky (around midday) and ranges from 1 (low risk) to 10 (maximum risk). In southern Spain, the mean UVI is approximately 6 and can reach up to 9 or sometimes 10 in the summer months. Although Fitzpatrick skin types II and III are most common, the elevated UVI indicates that the general population in southern Spain is at a high risk for developing skin cancer.

In our study the mean age of IWs was lower than OWs, which suggests that IWs may develop BCC at a younger age than OWs. This finding is consistent with studies showing that cumulative occupational UV exposure has been associated with development of BCCs in older age groups, while acute intermittent recreational sun exposure, particularly sustained in childhood and adolescence, is linked with BCC in younger patients.⁶

The role of sex as a risk factor for BCC remains unclear. Some reports show that BCC is more common in men than in women.^8-10 In our study, sex distribution was statistically significant (P=.002); there were more women in the IW cohort and more men in the OW cohort. These differences may be explained by cultural and lifestyle patterns, as women who are IWs tend to have office jobs in urban settings and wear modern fashion clothes at work and for recreation. In rural settings, women have agricultural jobs and tend to wear more traditional clothes that offer sun protection.

Positive family history has been suggested to be a constitutional risk factor for BCC development.^8,11,12 In our study, we observed that positive family history was more common in OWs, while most IWs had a negative family history. These differences were significant (P=.03), and OWs had a 2.6-fold increased likelihood of having a positive family history of BCC compared to IWs. Cultural and lifestyle patterns may partially explain this finding. In rural settings, workers tend to have the same job as their parents as a traditional way of life and therefore have similar patterns of UV exposure; in urban settings, individuals may have different jobs than their parents and therefore the pattern of UV exposure may be different. However, a genetic predisposition for developing BCC cannot be excluded. In addition, we have to consider that the information on family history of BCC in the patients was self-reported and not validated, which may limit the results.

The difference in history of second-degree sunburn in childhood was significantly higher in IWs than in OWs (P<.00001). The OW group had a significant rate of sunburns in adulthood (P=.002). The relationship between UV radiation and BCC is complex, and the patterns of sun exposure and their occurrence in different periods of lifetime (ie, childhood vs adulthood) remain controversial.¹³ The overall history of severe sunburns seems to be more important than simply the tendency to burn or tan,^14,15 and a history of sunburns in childhood and adolescence has been associated with early-onset BCC.⁶ Our findings were consistent in that the age of onset of BCCs was lower in IWs who had a history of sunburns in childhood. Basal cell carcinomas developed at older ages in OWs who had a higher incidence of sunburns in adulthood. However, we have to consider that the retrospective nature of the data collection on sunburns in childhood and adulthood was potentially limited, as the information was based on the patients’ memory. Additionally, other non-UV risk factors for BCC, such as ionizing radiation exposure, were not analyzed.

The majority of BCCs developed in sun-exposed areas of the head and neck in both cohorts, and only 35 (20%) and 28 (22%) BCCs were located on the trunk, arms, or legs in OWs and IWs, respectively. In our study, the rate of BCCs on the trunk was significantly lower in OWs than in IWs (P=.0035). Basal cell carcinomas on the trunk have been suggested to be linked to genetic susceptibility^16,17 and reduced DNA repair capacity¹⁸ rather than sun exposure. Our findings support this hypothesis and suggest that occupational sun exposure has no direct relation with truncal BCC. This outcome is consistent with the result of a case-control study conducted by Pelucchi et al¹⁹ (N=1040). The authors concluded that occupational UV exposure was not associated with truncal BCC development but with head/neck BCC, indicating that there may be different etiological mechanisms between truncal and head/neck BCC.¹⁹ In the largest BCC case series published in the literature with 13,457 specimens, the authors stated that tumors on the trunk may represent a particular variant of BCC, in which the theory of chronic versus intermittent UV exposure cannot be simply extrapolated as it is for the rest of BCC sites. Other factors such as genetic predisposition could be involved in the development of truncal BCC.²⁰ Similarly, Ramos et al²¹ suggested that nonmelanoma skin cancers in sun-protected anatomic sites may occur in individuals with impairment in the DNA repair process.

The classification of histological subtypes of BCC helps to predict tumor behavior,²² which can impact the prognosis. In our study, nodular BCC was the most common subtype in both cohorts, followed by superficial BCC. The nodular subtype was increased in OWs compared to IWs, while the superficial subtype was most common in IWs. Bastiaens et al²³ and McCormack et al²⁴ have suggested that the most frequent subtypes of BCC (nodular and superficial) may represent different tumors with distinct causal factors. According to these authors, nodular subtypes are associated with cumulative UV exposure, while superficial subtypes are associated with more intense and intermittent UV exposure. The results of the current study support this hypothesis, as the OW cohort with cumulative UV exposure showed more incidence of nodular BCC than IWs, while the patients with intense and intermittent sun exposure (the IWs) showed more risk of superficial BCC.

The importance of occupational UV exposure in OWs as a risk factor for BCC is still an ongoing discussion. Our data show that occupational UV exposure may be considered an etiological factor for BCC according to histological subtype and anatomic site. Our study is limited by the retrospective nature of the data collection regarding occupation and childhood sunburns, which were based on the patients’ memory and therefore potentially biased. Data regarding family history of BCC also was self-reported and not validated. Another limiting factor was that other non-UV risk factors for BCC, such as ionizing radiation exposure, were not considered. The limited sample size also may have impacted the study results. Among the strengths of the study are the complete response rate, the similar catchment area of OWs and IWs, the common hospital setting of the 2 cohorts, and the similar attention to medical history. All patients were obtained from the practice of a single referral dermatologist and are felt to be representative of our working area. The use of a single dermatologist reduces provider-associated variability.

Conclusion

According to the results of this study, OWs are more likely to develop nodular BCCs with no increased risk for superficial BCCs. The age of onset in OWs is older than in IWs. Some anatomical sites such as the trunk are more commonly affected in IWs. Truncal BCCs may have etiological factors other than UV exposure, such as a genetic predisposition. This study is useful to occupational safety representatives and physicians to stimulate the implementation of prevention strategies for this easily preventable malignancy and may encourage further research.

Epidermal nevi can occur in isolation or in association with internal abnormalities. Epidermal nevus syndrome (ENS) is a heterogeneous group of neurocutaneous disorders characterized by mosaicism and epidermal nevi found in association with various systemic abnormalities.^1-4 There are many possible associated systemic findings, including abnormalities of the central nervous, musculoskeletal, renal, and hematologic systems. Epidermal nevi have been associated with internal malignancies. We present the case of a patient with epidermal nevi associated with papillary transitional cell bladder carcinoma. According to a PubMed search of articles indexed for MEDLINE using the search terms transitional cell bladder carcinoma and epidermal nevus, there have only been 4 other cases of transitional cell bladder carcinoma and ENS reported in the literature,^5-8 2 of which were reports of papillary transitional cell bladder carcinoma.^5,6

Case Report

A 29-year-old woman presented to our clinic with a rash that had been present since 3 years of age. The emergency department consulted dermatology for evaluation of what was believed to be contact dermatitis; however, upon questioning the patient, it was revealed that the rash was chronic and persistent.

The rash was nonpruritic and was located on the face, hands (Figure 1), chest, buttocks, thighs, legs, and back (Figure 2). Although asymptomatic, the appearance of the skin caused the patient some emotional distress. As a child she had been evaluated by a dermatologist and a biopsy was performed, but she did not recall the results or have any records. She had been prescribed an oral medication by the dermatologist, but treatment was terminated early due to nausea. The skin lesions did not improve with the short course of treatment.

Eighteen months prior to presentation to our clinic, the patient was discovered to have hematuria on routine examination by her primary care physician. At that time, the patient underwent a workup for hematuria and a mass was discovered in the bladder via cystoscopy. A diagnosis of low-grade papillary transitional cell bladder carcinoma was made, and she underwent a partial cystectomy. No radiation or chemotherapy was required. The remainder of her medical history was only remarkable for asthma, which was well controlled with albuterol. On examination, generalized, hyperpigmented, reticulated patches, macules, and hyperpigmented verrucous plaques were distributed along the Blaschko lines, sparing the face. No limb abnormalities or dental or nail abnormalities were noted. Examination of the axillary and cervical lymph nodes was unremarkable, and no neurological abnormalities were noted. A 3-mm punch biopsy of the mid upper back was performed. Histopathology revealed papillomatous, nonorganoid, nonepidermolytic hyperplasia of the epidermis with elongated rete ridges (Figure 3), which was diagnosed as a nonorganoid nonepidermolytic epidermal nevus.

Comment

Epidermal nevus syndrome is a group of disorders characterized by both local or systematized epidermal nevi and systemic findings. Solomon et al⁴ first coined the term epidermal nevus syndrome more than 40 years ago; however, since then there has been confusion about how to define ENS. Epidermal nevus syndrome has been considered an umbrella term that includes more specific syndromes involving epidermal nevi, such as Proteus syndrome and Schimmelpenning syndrome; conversely, it also has been considered a term for those who do not meet the criteria for more specific syndromes.^1,9 Happle¹ discussed that the genetic variations found in ENS warrant recognition. Simply put, ENS is a heterogeneous group of syndromes that are similar in that they involve epidermal nevi and internal abnormalities but are genetically distinct. The list of definitive ENSs, as suggested by Happle¹ and others, will likely continue to grow.^3,5

The exact pathomechanism of ENS is unknown, but the clinical presentation most likely represents a lethal disorder mitigated by mosaicism.^2,9 Gene defects vary depending on the specific ENS. For instance, the phosphatase and tensin homolog gene, PTEN, mutations have been associated with type 2 segmental Cowden disease. Fibroblast growth factor receptor 3, FGFR3, mutations have been linked to Garcia-Hafner-Happle syndrome.³FGFR3 mutations have been found in nonepidermolytic epidermal nevi, and some suggest that the majority of epidermal nevi exhibit mutations in FGFR3.^5,10,11 On the other hand, other gene defects have not been elucidated, such as in Schimmelpenning syndrome.³

Clinically, ENS may involve nonepidermolytic verrucous nevi, sebaceous nevi, organoid nevi, linear Cowden nevi, and woolly hair nevi. Lesions may be flesh-colored, pink, yellow, or hyperpigmented plaques in a blaschkoid distribution and may be localized or systematized. Nevi typically are present at birth or develop within the first year of life.^9,12,13 Other cutaneous findings may be noted apart from epidermal nevi, including melanocytic nevi, aplasia cutis congenita, and hemangiomas.^13,14

Extracutaneous findings include central nervous system, skeletal, ocular, cardiac, and genitourinary defects, which are often observed in these patients.^3,9,13,14 Central nervous system findings are seen in 50% to 70% of cases, with seizures and mental retardation among the most common.^13-15 Genitourinary abnormalities associated with epidermal nevi, including horseshoe kidney, cystic kidney, duplicated collecting system, testicular and paratesticular tumors, and hypospadias have been documented in the literature.¹⁶ Our patient had a history of papillary transitional cell bladder carcinoma, which is rare for a patient younger than 30 years. The overall median age of diagnosis of bladder cancer is 65 years, and it is more common in men than in women.¹⁷ Transitional cell carcinomas account for approximately 90% of all bladder cancers in the United States. Other common types of bladder cancer include squamous cell carcinoma, adenocarcinoma, and rhabdomyosarcoma.¹⁶ Typically, transitional cell carcinoma is associated with smoking, exposure to aniline dyes, cyclophosphamide, and living in industrialized areas.^16,17 Individuals who work with textiles, dyes, leather, tires, rubber, and/or petroleum; painters; truck drivers; drill press operators; and hairdressers are at an increased risk for development of bladder cancer.¹⁶

Interestingly, it has been shown in some studies that papillary transitional cell bladder carcinoma frequently is associated with FGFR3 mutations, which may be the missing link in the rare finding of papillary transitional cell bladder carcinoma and epidermal nevi.^5,18,19 In addition, PTEN mutations also have been identified in low-grade papillary transitional cell carcinomas of the bladder, another gene linked to an ENS with type 2 segmental Cowden disease.^3,20

Histopathologically, epidermal nevi have 10 different descriptions. Our patient had a nonorganoid nonepidermolytic epidermal nevus characterized by hyperkeratosis, acanthosis, papillomatosis, and elongated rete ridges. Focal acantholysis and epidermolytic hyperkeratosis also is seen in some epidermal nevi but was not seen in this case.^9,21

Simple epidermal nevi occur in approximately 1 in 1000 newborns; however, when a child presents with multiple or systematized epidermal nevi, investigation should be undertaken for other possible associations.^13,14 Of note, there have been several cases of squamous cell, verrucous, basal cell, and adnexal carcinomas arising in linear epidermal nevi.^22-24

Epidermal nevi can be difficult to treat. Some patients are troubled by the appearance of these nevi, especially those with systematized disease. Unfortunately, for patients with multiple nevi or systematized disease, there are no consistently effective treatment options; however, there are case reports^25,26 in the literature citing improvement or cure of epidermal nevi with full-thickness excision, continuous and pulsed CO₂ laser, pulsed dye laser, and erbium-doped YAG laser.²⁵ Other therapies that have been purported to help improve epidermal nevi are topical and oral retinoids, corticosteroids, topical 5-fluorouracil, anthralin, and podophyllin.²⁶

Conclusion

Transitional cell bladder carcinoma is rare in patients in the third decade of life and younger. Given the age of our patient and her concomitant lack of risk factors, such as older age, history of smoking, and exposure to certain chemicals (eg, aniline dyes) and medications (eg, cyclophosphamide), it is more likely that the finding of papillary transitional cell bladder carcinoma and ENS are related. A clear genetic link between ENS and transitional cell papillary bladder carcinoma has yet to be elucidated, but the FGFR3 gene is promising.

Epidermal nevi can occur in isolation or in association with internal abnormalities. Epidermal nevus syndrome (ENS) is a heterogeneous group of neurocutaneous disorders characterized by mosaicism and epidermal nevi found in association with various systemic abnormalities.^1-4 There are many possible associated systemic findings, including abnormalities of the central nervous, musculoskeletal, renal, and hematologic systems. Epidermal nevi have been associated with internal malignancies. We present the case of a patient with epidermal nevi associated with papillary transitional cell bladder carcinoma. According to a PubMed search of articles indexed for MEDLINE using the search terms transitional cell bladder carcinoma and epidermal nevus, there have only been 4 other cases of transitional cell bladder carcinoma and ENS reported in the literature,^5-8 2 of which were reports of papillary transitional cell bladder carcinoma.^5,6

Case Report

A 29-year-old woman presented to our clinic with a rash that had been present since 3 years of age. The emergency department consulted dermatology for evaluation of what was believed to be contact dermatitis; however, upon questioning the patient, it was revealed that the rash was chronic and persistent.

The rash was nonpruritic and was located on the face, hands (Figure 1), chest, buttocks, thighs, legs, and back (Figure 2). Although asymptomatic, the appearance of the skin caused the patient some emotional distress. As a child she had been evaluated by a dermatologist and a biopsy was performed, but she did not recall the results or have any records. She had been prescribed an oral medication by the dermatologist, but treatment was terminated early due to nausea. The skin lesions did not improve with the short course of treatment.

Eighteen months prior to presentation to our clinic, the patient was discovered to have hematuria on routine examination by her primary care physician. At that time, the patient underwent a workup for hematuria and a mass was discovered in the bladder via cystoscopy. A diagnosis of low-grade papillary transitional cell bladder carcinoma was made, and she underwent a partial cystectomy. No radiation or chemotherapy was required. The remainder of her medical history was only remarkable for asthma, which was well controlled with albuterol. On examination, generalized, hyperpigmented, reticulated patches, macules, and hyperpigmented verrucous plaques were distributed along the Blaschko lines, sparing the face. No limb abnormalities or dental or nail abnormalities were noted. Examination of the axillary and cervical lymph nodes was unremarkable, and no neurological abnormalities were noted. A 3-mm punch biopsy of the mid upper back was performed. Histopathology revealed papillomatous, nonorganoid, nonepidermolytic hyperplasia of the epidermis with elongated rete ridges (Figure 3), which was diagnosed as a nonorganoid nonepidermolytic epidermal nevus.

Comment

Epidermal nevus syndrome is a group of disorders characterized by both local or systematized epidermal nevi and systemic findings. Solomon et al⁴ first coined the term epidermal nevus syndrome more than 40 years ago; however, since then there has been confusion about how to define ENS. Epidermal nevus syndrome has been considered an umbrella term that includes more specific syndromes involving epidermal nevi, such as Proteus syndrome and Schimmelpenning syndrome; conversely, it also has been considered a term for those who do not meet the criteria for more specific syndromes.^1,9 Happle¹ discussed that the genetic variations found in ENS warrant recognition. Simply put, ENS is a heterogeneous group of syndromes that are similar in that they involve epidermal nevi and internal abnormalities but are genetically distinct. The list of definitive ENSs, as suggested by Happle¹ and others, will likely continue to grow.^3,5

The exact pathomechanism of ENS is unknown, but the clinical presentation most likely represents a lethal disorder mitigated by mosaicism.^2,9 Gene defects vary depending on the specific ENS. For instance, the phosphatase and tensin homolog gene, PTEN, mutations have been associated with type 2 segmental Cowden disease. Fibroblast growth factor receptor 3, FGFR3, mutations have been linked to Garcia-Hafner-Happle syndrome.³FGFR3 mutations have been found in nonepidermolytic epidermal nevi, and some suggest that the majority of epidermal nevi exhibit mutations in FGFR3.^5,10,11 On the other hand, other gene defects have not been elucidated, such as in Schimmelpenning syndrome.³

Clinically, ENS may involve nonepidermolytic verrucous nevi, sebaceous nevi, organoid nevi, linear Cowden nevi, and woolly hair nevi. Lesions may be flesh-colored, pink, yellow, or hyperpigmented plaques in a blaschkoid distribution and may be localized or systematized. Nevi typically are present at birth or develop within the first year of life.^9,12,13 Other cutaneous findings may be noted apart from epidermal nevi, including melanocytic nevi, aplasia cutis congenita, and hemangiomas.^13,14

Extracutaneous findings include central nervous system, skeletal, ocular, cardiac, and genitourinary defects, which are often observed in these patients.^3,9,13,14 Central nervous system findings are seen in 50% to 70% of cases, with seizures and mental retardation among the most common.^13-15 Genitourinary abnormalities associated with epidermal nevi, including horseshoe kidney, cystic kidney, duplicated collecting system, testicular and paratesticular tumors, and hypospadias have been documented in the literature.¹⁶ Our patient had a history of papillary transitional cell bladder carcinoma, which is rare for a patient younger than 30 years. The overall median age of diagnosis of bladder cancer is 65 years, and it is more common in men than in women.¹⁷ Transitional cell carcinomas account for approximately 90% of all bladder cancers in the United States. Other common types of bladder cancer include squamous cell carcinoma, adenocarcinoma, and rhabdomyosarcoma.¹⁶ Typically, transitional cell carcinoma is associated with smoking, exposure to aniline dyes, cyclophosphamide, and living in industrialized areas.^16,17 Individuals who work with textiles, dyes, leather, tires, rubber, and/or petroleum; painters; truck drivers; drill press operators; and hairdressers are at an increased risk for development of bladder cancer.¹⁶

Interestingly, it has been shown in some studies that papillary transitional cell bladder carcinoma frequently is associated with FGFR3 mutations, which may be the missing link in the rare finding of papillary transitional cell bladder carcinoma and epidermal nevi.^5,18,19 In addition, PTEN mutations also have been identified in low-grade papillary transitional cell carcinomas of the bladder, another gene linked to an ENS with type 2 segmental Cowden disease.^3,20

Histopathologically, epidermal nevi have 10 different descriptions. Our patient had a nonorganoid nonepidermolytic epidermal nevus characterized by hyperkeratosis, acanthosis, papillomatosis, and elongated rete ridges. Focal acantholysis and epidermolytic hyperkeratosis also is seen in some epidermal nevi but was not seen in this case.^9,21

Simple epidermal nevi occur in approximately 1 in 1000 newborns; however, when a child presents with multiple or systematized epidermal nevi, investigation should be undertaken for other possible associations.^13,14 Of note, there have been several cases of squamous cell, verrucous, basal cell, and adnexal carcinomas arising in linear epidermal nevi.^22-24

Epidermal nevi can be difficult to treat. Some patients are troubled by the appearance of these nevi, especially those with systematized disease. Unfortunately, for patients with multiple nevi or systematized disease, there are no consistently effective treatment options; however, there are case reports^25,26 in the literature citing improvement or cure of epidermal nevi with full-thickness excision, continuous and pulsed CO₂ laser, pulsed dye laser, and erbium-doped YAG laser.²⁵ Other therapies that have been purported to help improve epidermal nevi are topical and oral retinoids, corticosteroids, topical 5-fluorouracil, anthralin, and podophyllin.²⁶

Conclusion

Transitional cell bladder carcinoma is rare in patients in the third decade of life and younger. Given the age of our patient and her concomitant lack of risk factors, such as older age, history of smoking, and exposure to certain chemicals (eg, aniline dyes) and medications (eg, cyclophosphamide), it is more likely that the finding of papillary transitional cell bladder carcinoma and ENS are related. A clear genetic link between ENS and transitional cell papillary bladder carcinoma has yet to be elucidated, but the FGFR3 gene is promising.

Epidermal nevi can occur in isolation or in association with internal abnormalities. Epidermal nevus syndrome (ENS) is a heterogeneous group of neurocutaneous disorders characterized by mosaicism and epidermal nevi found in association with various systemic abnormalities.^1-4 There are many possible associated systemic findings, including abnormalities of the central nervous, musculoskeletal, renal, and hematologic systems. Epidermal nevi have been associated with internal malignancies. We present the case of a patient with epidermal nevi associated with papillary transitional cell bladder carcinoma. According to a PubMed search of articles indexed for MEDLINE using the search terms transitional cell bladder carcinoma and epidermal nevus, there have only been 4 other cases of transitional cell bladder carcinoma and ENS reported in the literature,^5-8 2 of which were reports of papillary transitional cell bladder carcinoma.^5,6

Case Report

A 29-year-old woman presented to our clinic with a rash that had been present since 3 years of age. The emergency department consulted dermatology for evaluation of what was believed to be contact dermatitis; however, upon questioning the patient, it was revealed that the rash was chronic and persistent.

The rash was nonpruritic and was located on the face, hands (Figure 1), chest, buttocks, thighs, legs, and back (Figure 2). Although asymptomatic, the appearance of the skin caused the patient some emotional distress. As a child she had been evaluated by a dermatologist and a biopsy was performed, but she did not recall the results or have any records. She had been prescribed an oral medication by the dermatologist, but treatment was terminated early due to nausea. The skin lesions did not improve with the short course of treatment.

Eighteen months prior to presentation to our clinic, the patient was discovered to have hematuria on routine examination by her primary care physician. At that time, the patient underwent a workup for hematuria and a mass was discovered in the bladder via cystoscopy. A diagnosis of low-grade papillary transitional cell bladder carcinoma was made, and she underwent a partial cystectomy. No radiation or chemotherapy was required. The remainder of her medical history was only remarkable for asthma, which was well controlled with albuterol. On examination, generalized, hyperpigmented, reticulated patches, macules, and hyperpigmented verrucous plaques were distributed along the Blaschko lines, sparing the face. No limb abnormalities or dental or nail abnormalities were noted. Examination of the axillary and cervical lymph nodes was unremarkable, and no neurological abnormalities were noted. A 3-mm punch biopsy of the mid upper back was performed. Histopathology revealed papillomatous, nonorganoid, nonepidermolytic hyperplasia of the epidermis with elongated rete ridges (Figure 3), which was diagnosed as a nonorganoid nonepidermolytic epidermal nevus.

Comment

Epidermal nevus syndrome is a group of disorders characterized by both local or systematized epidermal nevi and systemic findings. Solomon et al⁴ first coined the term epidermal nevus syndrome more than 40 years ago; however, since then there has been confusion about how to define ENS. Epidermal nevus syndrome has been considered an umbrella term that includes more specific syndromes involving epidermal nevi, such as Proteus syndrome and Schimmelpenning syndrome; conversely, it also has been considered a term for those who do not meet the criteria for more specific syndromes.^1,9 Happle¹ discussed that the genetic variations found in ENS warrant recognition. Simply put, ENS is a heterogeneous group of syndromes that are similar in that they involve epidermal nevi and internal abnormalities but are genetically distinct. The list of definitive ENSs, as suggested by Happle¹ and others, will likely continue to grow.^3,5

The exact pathomechanism of ENS is unknown, but the clinical presentation most likely represents a lethal disorder mitigated by mosaicism.^2,9 Gene defects vary depending on the specific ENS. For instance, the phosphatase and tensin homolog gene, PTEN, mutations have been associated with type 2 segmental Cowden disease. Fibroblast growth factor receptor 3, FGFR3, mutations have been linked to Garcia-Hafner-Happle syndrome.³FGFR3 mutations have been found in nonepidermolytic epidermal nevi, and some suggest that the majority of epidermal nevi exhibit mutations in FGFR3.^5,10,11 On the other hand, other gene defects have not been elucidated, such as in Schimmelpenning syndrome.³

Clinically, ENS may involve nonepidermolytic verrucous nevi, sebaceous nevi, organoid nevi, linear Cowden nevi, and woolly hair nevi. Lesions may be flesh-colored, pink, yellow, or hyperpigmented plaques in a blaschkoid distribution and may be localized or systematized. Nevi typically are present at birth or develop within the first year of life.^9,12,13 Other cutaneous findings may be noted apart from epidermal nevi, including melanocytic nevi, aplasia cutis congenita, and hemangiomas.^13,14

Extracutaneous findings include central nervous system, skeletal, ocular, cardiac, and genitourinary defects, which are often observed in these patients.^3,9,13,14 Central nervous system findings are seen in 50% to 70% of cases, with seizures and mental retardation among the most common.^13-15 Genitourinary abnormalities associated with epidermal nevi, including horseshoe kidney, cystic kidney, duplicated collecting system, testicular and paratesticular tumors, and hypospadias have been documented in the literature.¹⁶ Our patient had a history of papillary transitional cell bladder carcinoma, which is rare for a patient younger than 30 years. The overall median age of diagnosis of bladder cancer is 65 years, and it is more common in men than in women.¹⁷ Transitional cell carcinomas account for approximately 90% of all bladder cancers in the United States. Other common types of bladder cancer include squamous cell carcinoma, adenocarcinoma, and rhabdomyosarcoma.¹⁶ Typically, transitional cell carcinoma is associated with smoking, exposure to aniline dyes, cyclophosphamide, and living in industrialized areas.^16,17 Individuals who work with textiles, dyes, leather, tires, rubber, and/or petroleum; painters; truck drivers; drill press operators; and hairdressers are at an increased risk for development of bladder cancer.¹⁶

Interestingly, it has been shown in some studies that papillary transitional cell bladder carcinoma frequently is associated with FGFR3 mutations, which may be the missing link in the rare finding of papillary transitional cell bladder carcinoma and epidermal nevi.^5,18,19 In addition, PTEN mutations also have been identified in low-grade papillary transitional cell carcinomas of the bladder, another gene linked to an ENS with type 2 segmental Cowden disease.^3,20

Histopathologically, epidermal nevi have 10 different descriptions. Our patient had a nonorganoid nonepidermolytic epidermal nevus characterized by hyperkeratosis, acanthosis, papillomatosis, and elongated rete ridges. Focal acantholysis and epidermolytic hyperkeratosis also is seen in some epidermal nevi but was not seen in this case.^9,21

Simple epidermal nevi occur in approximately 1 in 1000 newborns; however, when a child presents with multiple or systematized epidermal nevi, investigation should be undertaken for other possible associations.^13,14 Of note, there have been several cases of squamous cell, verrucous, basal cell, and adnexal carcinomas arising in linear epidermal nevi.^22-24

Epidermal nevi can be difficult to treat. Some patients are troubled by the appearance of these nevi, especially those with systematized disease. Unfortunately, for patients with multiple nevi or systematized disease, there are no consistently effective treatment options; however, there are case reports^25,26 in the literature citing improvement or cure of epidermal nevi with full-thickness excision, continuous and pulsed CO₂ laser, pulsed dye laser, and erbium-doped YAG laser.²⁵ Other therapies that have been purported to help improve epidermal nevi are topical and oral retinoids, corticosteroids, topical 5-fluorouracil, anthralin, and podophyllin.²⁶

Conclusion

Transitional cell bladder carcinoma is rare in patients in the third decade of life and younger. Given the age of our patient and her concomitant lack of risk factors, such as older age, history of smoking, and exposure to certain chemicals (eg, aniline dyes) and medications (eg, cyclophosphamide), it is more likely that the finding of papillary transitional cell bladder carcinoma and ENS are related. A clear genetic link between ENS and transitional cell papillary bladder carcinoma has yet to be elucidated, but the FGFR3 gene is promising.

Differentiation between a primary adnexal carcinoma and a metastatic carcinoma to the skin is a challenging yet critical task for dermatologists and pathologists. Carcinomas that have metastasized to the skin are a sign of widespread systemic involvement and poor prognosis, while primary adnexal carcinomas tend to progress with an indolent clinical course. Although many patients with cutaneous metastases from an internal primary neoplasm can expect a median survival of no more than 12 months,¹ patients with primary adnexal carcinomas are reported to have a 5-year survival rate of 95.5% for localized disease and 85% with spread to regional lymph nodes.² We report a case of multiple cutaneous neoplasms of unknown primary origin in a 71-year-old man and describe our approach to identification of the possible primary site as well as management of the disease.  

Case Report

A 71-year-old man initially presented to his primary physician for evaluation of a mass on the left side of the neck of 3 months' duration. On physical examination, a firm 2.5×3.0-cm nodule was noted at the anterior border of the trapezius muscle. Palpation of the thyroid revealed an additional right-sided nodule. The submandibular and parotid glands were unremarkable to palpation. The patient was referred to general surgery for biopsy, which revealed an infiltrating, moderately differentiated adenocarcinoma with extensive lymphatic permeation. Immunohistochemical staining for cytokeratin (CK) 7 was positive, while CK20 and thyroid transcription factor 1 were negative. A positron emission tomography/computed tomography (CT) fusion scan demonstrated 3 areas of enhanced uptake: one in the right side of the thyroid, a second corresponding to the mass on the left side of the neck at the level of the trapezius muscle, and a third in the left masseter muscle. Surgical excision with negative margins with possible chemotherapy was recommended; however, the patient declined treatment and was lost to follow-up until 2 years later when he presented to his primary physician with an additional lesion on his scalp.

Four years after the biopsy, the patient presented to the dermatology department with additional tumor nodules including a 4-cm, annular, indurated, focally eroded plaque on the left side of the lateral neck (Figure 1); 3 separate 1-cm nodules on the right side of the lateral neck; and an ulcerated, crusted, 10×8-cm plaque on the posterior aspect of the scalp. Despite the extensive lesions, the patient remained in good health and reported no recent weight loss or signs or symptoms of systemic involvement. The posterior scalp lesion, which developed 2 years after the initial appearance of the mass on the neck and was thought to represent a possible metastasis of the tumor, was biopsied and showed diffuse infiltration of the dermis by poorly differentiated tumor cells with vacuolated cytoplasm arranged in nests and cords and sometimes in a single-file arrangement (Figure 2). A CT scan demonstrated pretracheal lymphadenopathy as well as small intraparenchymal and subpleural pulmonary nodules throughout both lung fields.

Another scalp biopsy was taken. Tumor cells were negative on mucicarmine staining. Additional immunohistochemical staining, including a periodic acid-Schiff stain with diastase digestion for epithelial mucin revealed minimal luminal positivity. Immunostaining was positive for CK7, carcinoembryonic antigen, CD15, estrogen receptor, progesterone receptor, gross cystic disease fluid protein 15 (GCDFP-15), and mammaglobin, and negative for CK20, podoplanin, thyroid transcription factor 1, S-100 protein, p63, and prostate specific antigen. ERBB2 (formerly HER2/neu) staining was negative according to fluorescence in situ hybridization analysis. Tumor cells showed a Ki-67 nuclear proliferation index of greater than 50%, indicating progression to aggressive carcinoma. 

Based on the histological and immunochemical studies, the differential diagnosis included primary cutaneous apocrine carcinoma versus breast carcinoma; however, the prolonged clinical progression of these lesions favored a primary cutaneous adnexal tumor over a metastatic adenocarcinoma. Nevertheless, despite the initially indolent growth of the lesions over the first 5 years, the Ki-67 proliferation index and presence of widespread metastases on the posterior scalp indicated progression to an aggressive carcinoma. Chemotherapy was recommended as the treatment of choice. At his most recent follow-up visit 4 months later, the patient chose to begin treatment with tamoxifen and refused other treatment options.

Comment

The distinction between primary adnexal and metastatic adenocarcinomas of the skin is challenging both clinically and histologically. Some pathologists have argued that metastatic breast carcinomas and primary cutaneous apocrine carcinomas are essentially indistinguishable.³ Patients with cutaneous metastases, which occur in approximately 5.3% of all malignancies,⁴ typically can expect survival of no more than 12 months from the time of detection.¹ In contrast, primary apocrine carcinomas of the skin, though much less common, carry a remarkably better prognosis, with 5-year relative survival rates of 95.5% and 85.5% reported for patients with localized disease and spread to regional lymph nodes, respectively.²

Fewer than 100 cases of primary cutaneous adnexal (apocrine) carcinomas have been reported overall, with the earliest known report dating back to 1944.⁵ According to the literature, primary apocrine carcinomas were diagnosed at a median age of 66 years and were slightly more common in females than males.^2,6 Apocrine carcinomas were seen most frequently on the head, neck, and trunk,² generally presenting in the form of asymptomatic nodules or plaques of 2 to 3 cm in size, with gradual progression occurring over months to years.⁶ Approximately 40% of patients have been reported with positive regional lymph nodes at diagnosis. Treatment of apocrine carcinoma typically has involved local excision with clear margins with or without lymph node dissection. Chemotherapy and radiation therapy have shown no proven benefit.⁷

Currently, there is no standardized approach to evaluating patients with possible cutaneous metastasis versus primary cutaneous adnexal carcinomas. Imaging studies such as mammography and abdominal CT typically reveal an internal primary cancer in one-third of patients. However, additional studies such as gastrointestinal radiography, chest and pelvic CT, barium enema, and intravenous pyelogram have shown to be of limited value.⁸ Although specificity and sensitivity of immunohistochemistry is limited, a number of immunomarkers, including CK7 and CK20, are routinely studied to narrow the differential diagnosis of a cutaneous neoplasm of unclear origin. Urothelial, gastric, colorectal, and pancreatic carcinomas generally are positive for CK20; CK7-positive adenocarcinomas include salivary, non-small cell lung, breast, ovarian, pancreatic, endometrial, and transitional cell adenocarcinomas. Carcinomas negative for both CK7 and CK20 include colorectal, hepatocellular, renal cell, prostate, and squamous cell carcinoma of the lung. 

The presence of positive staining for estrogen and progesterone receptors as well as GCDFP-15 and mammaglobin raised the possibility of primary breast adenocarcinoma in our patient, but given that these markers can be positive in primary cutaneous adnexal tumors, immunohistochemistry results were not able to provide a definitive primary site. The overall staining pattern was nearly identical to 26 cases of primary cutaneous cribriform apocrine carcinoma, which was found to be positive for CK7 and carcinoembryonic antigen, and negative for CK20 and S-100. The only difference was in GCDFP-15 staining, which was positive in our case and negative in the cases of cribriform apocrine carcinoma.⁹ Histologic features favoring a primary apocrine origin include normal apocrine glands in the vicinity, glandular structures with decapitation secretion high in the dermis, and intracytoplasmic iron granules.¹⁰ Additionally, positive estrogen receptor staining appears to be much more common in apocrine carcinomas (5/10) than in eccrine carcinomas (1/7).¹¹

A number of other markers have been investigated for possible diagnostic utility for distinction between primary adnexal carcinomas and metastatic adenocarcinomas. The nuclear transcription factor p63, which plays a role in keratinocyte differentiation, is preferentially expressed in a number of primary adnexal carcinomas and is purported to be the most sensitive marker overall, with a sensitivity of 78% to 91%.^12-14 However, p63 has shown incomplete specificity for primary adnexal neoplasms, having been reported as positive in 11% to 22% of adenocarcinomas metastatic to skin.^15-18 Nestin and CK15, which are expressed in hair follicle progenitor cells, also are potential specific markers for some primary adnexal lesions, specifically eccrine carcinoma, porocarcinoma, hidradenocarcinoma, and microcystic adnexal carcinoma; however, in one report, none of the apocrine carcinomas were positive for p63, cytokeratin 15, or D2-40.¹⁹ Thus, while markers for some primary adnexal neoplasms are emerging, specific tests at the immunohistochemical level for the apocrine carcinoma subgroup are still lacking.

Conclusion

In summary, a conclusive distinction between primary cutaneous apocrine carcinoma and metastatic adenocarcinoma to the skin remains challenging. Although new markers provide more specificity and sensitivity for neoplasms of eccrine origin, these markers do not appear to differentiate between primary apocrine carcinoma and metastatic breast carcinoma. In this case, as in other recent reports, diagnosis remained dependent on the clinical course of the patient. Although considerable progress has been made regarding immunohistochemical analysis of these cases, additional markers, especially ones more specific for primary skin cancers with apocrine differentiation, are still needed.

Differentiation between a primary adnexal carcinoma and a metastatic carcinoma to the skin is a challenging yet critical task for dermatologists and pathologists. Carcinomas that have metastasized to the skin are a sign of widespread systemic involvement and poor prognosis, while primary adnexal carcinomas tend to progress with an indolent clinical course. Although many patients with cutaneous metastases from an internal primary neoplasm can expect a median survival of no more than 12 months,¹ patients with primary adnexal carcinomas are reported to have a 5-year survival rate of 95.5% for localized disease and 85% with spread to regional lymph nodes.² We report a case of multiple cutaneous neoplasms of unknown primary origin in a 71-year-old man and describe our approach to identification of the possible primary site as well as management of the disease.  

Case Report

A 71-year-old man initially presented to his primary physician for evaluation of a mass on the left side of the neck of 3 months' duration. On physical examination, a firm 2.5×3.0-cm nodule was noted at the anterior border of the trapezius muscle. Palpation of the thyroid revealed an additional right-sided nodule. The submandibular and parotid glands were unremarkable to palpation. The patient was referred to general surgery for biopsy, which revealed an infiltrating, moderately differentiated adenocarcinoma with extensive lymphatic permeation. Immunohistochemical staining for cytokeratin (CK) 7 was positive, while CK20 and thyroid transcription factor 1 were negative. A positron emission tomography/computed tomography (CT) fusion scan demonstrated 3 areas of enhanced uptake: one in the right side of the thyroid, a second corresponding to the mass on the left side of the neck at the level of the trapezius muscle, and a third in the left masseter muscle. Surgical excision with negative margins with possible chemotherapy was recommended; however, the patient declined treatment and was lost to follow-up until 2 years later when he presented to his primary physician with an additional lesion on his scalp.

Four years after the biopsy, the patient presented to the dermatology department with additional tumor nodules including a 4-cm, annular, indurated, focally eroded plaque on the left side of the lateral neck (Figure 1); 3 separate 1-cm nodules on the right side of the lateral neck; and an ulcerated, crusted, 10×8-cm plaque on the posterior aspect of the scalp. Despite the extensive lesions, the patient remained in good health and reported no recent weight loss or signs or symptoms of systemic involvement. The posterior scalp lesion, which developed 2 years after the initial appearance of the mass on the neck and was thought to represent a possible metastasis of the tumor, was biopsied and showed diffuse infiltration of the dermis by poorly differentiated tumor cells with vacuolated cytoplasm arranged in nests and cords and sometimes in a single-file arrangement (Figure 2). A CT scan demonstrated pretracheal lymphadenopathy as well as small intraparenchymal and subpleural pulmonary nodules throughout both lung fields.

Another scalp biopsy was taken. Tumor cells were negative on mucicarmine staining. Additional immunohistochemical staining, including a periodic acid-Schiff stain with diastase digestion for epithelial mucin revealed minimal luminal positivity. Immunostaining was positive for CK7, carcinoembryonic antigen, CD15, estrogen receptor, progesterone receptor, gross cystic disease fluid protein 15 (GCDFP-15), and mammaglobin, and negative for CK20, podoplanin, thyroid transcription factor 1, S-100 protein, p63, and prostate specific antigen. ERBB2 (formerly HER2/neu) staining was negative according to fluorescence in situ hybridization analysis. Tumor cells showed a Ki-67 nuclear proliferation index of greater than 50%, indicating progression to aggressive carcinoma. 

Based on the histological and immunochemical studies, the differential diagnosis included primary cutaneous apocrine carcinoma versus breast carcinoma; however, the prolonged clinical progression of these lesions favored a primary cutaneous adnexal tumor over a metastatic adenocarcinoma. Nevertheless, despite the initially indolent growth of the lesions over the first 5 years, the Ki-67 proliferation index and presence of widespread metastases on the posterior scalp indicated progression to an aggressive carcinoma. Chemotherapy was recommended as the treatment of choice. At his most recent follow-up visit 4 months later, the patient chose to begin treatment with tamoxifen and refused other treatment options.

Comment

The distinction between primary adnexal and metastatic adenocarcinomas of the skin is challenging both clinically and histologically. Some pathologists have argued that metastatic breast carcinomas and primary cutaneous apocrine carcinomas are essentially indistinguishable.³ Patients with cutaneous metastases, which occur in approximately 5.3% of all malignancies,⁴ typically can expect survival of no more than 12 months from the time of detection.¹ In contrast, primary apocrine carcinomas of the skin, though much less common, carry a remarkably better prognosis, with 5-year relative survival rates of 95.5% and 85.5% reported for patients with localized disease and spread to regional lymph nodes, respectively.²

Fewer than 100 cases of primary cutaneous adnexal (apocrine) carcinomas have been reported overall, with the earliest known report dating back to 1944.⁵ According to the literature, primary apocrine carcinomas were diagnosed at a median age of 66 years and were slightly more common in females than males.^2,6 Apocrine carcinomas were seen most frequently on the head, neck, and trunk,² generally presenting in the form of asymptomatic nodules or plaques of 2 to 3 cm in size, with gradual progression occurring over months to years.⁶ Approximately 40% of patients have been reported with positive regional lymph nodes at diagnosis. Treatment of apocrine carcinoma typically has involved local excision with clear margins with or without lymph node dissection. Chemotherapy and radiation therapy have shown no proven benefit.⁷

Currently, there is no standardized approach to evaluating patients with possible cutaneous metastasis versus primary cutaneous adnexal carcinomas. Imaging studies such as mammography and abdominal CT typically reveal an internal primary cancer in one-third of patients. However, additional studies such as gastrointestinal radiography, chest and pelvic CT, barium enema, and intravenous pyelogram have shown to be of limited value.⁸ Although specificity and sensitivity of immunohistochemistry is limited, a number of immunomarkers, including CK7 and CK20, are routinely studied to narrow the differential diagnosis of a cutaneous neoplasm of unclear origin. Urothelial, gastric, colorectal, and pancreatic carcinomas generally are positive for CK20; CK7-positive adenocarcinomas include salivary, non-small cell lung, breast, ovarian, pancreatic, endometrial, and transitional cell adenocarcinomas. Carcinomas negative for both CK7 and CK20 include colorectal, hepatocellular, renal cell, prostate, and squamous cell carcinoma of the lung. 

The presence of positive staining for estrogen and progesterone receptors as well as GCDFP-15 and mammaglobin raised the possibility of primary breast adenocarcinoma in our patient, but given that these markers can be positive in primary cutaneous adnexal tumors, immunohistochemistry results were not able to provide a definitive primary site. The overall staining pattern was nearly identical to 26 cases of primary cutaneous cribriform apocrine carcinoma, which was found to be positive for CK7 and carcinoembryonic antigen, and negative for CK20 and S-100. The only difference was in GCDFP-15 staining, which was positive in our case and negative in the cases of cribriform apocrine carcinoma.⁹ Histologic features favoring a primary apocrine origin include normal apocrine glands in the vicinity, glandular structures with decapitation secretion high in the dermis, and intracytoplasmic iron granules.¹⁰ Additionally, positive estrogen receptor staining appears to be much more common in apocrine carcinomas (5/10) than in eccrine carcinomas (1/7).¹¹

A number of other markers have been investigated for possible diagnostic utility for distinction between primary adnexal carcinomas and metastatic adenocarcinomas. The nuclear transcription factor p63, which plays a role in keratinocyte differentiation, is preferentially expressed in a number of primary adnexal carcinomas and is purported to be the most sensitive marker overall, with a sensitivity of 78% to 91%.^12-14 However, p63 has shown incomplete specificity for primary adnexal neoplasms, having been reported as positive in 11% to 22% of adenocarcinomas metastatic to skin.^15-18 Nestin and CK15, which are expressed in hair follicle progenitor cells, also are potential specific markers for some primary adnexal lesions, specifically eccrine carcinoma, porocarcinoma, hidradenocarcinoma, and microcystic adnexal carcinoma; however, in one report, none of the apocrine carcinomas were positive for p63, cytokeratin 15, or D2-40.¹⁹ Thus, while markers for some primary adnexal neoplasms are emerging, specific tests at the immunohistochemical level for the apocrine carcinoma subgroup are still lacking.

Conclusion

In summary, a conclusive distinction between primary cutaneous apocrine carcinoma and metastatic adenocarcinoma to the skin remains challenging. Although new markers provide more specificity and sensitivity for neoplasms of eccrine origin, these markers do not appear to differentiate between primary apocrine carcinoma and metastatic breast carcinoma. In this case, as in other recent reports, diagnosis remained dependent on the clinical course of the patient. Although considerable progress has been made regarding immunohistochemical analysis of these cases, additional markers, especially ones more specific for primary skin cancers with apocrine differentiation, are still needed.

Differentiation between a primary adnexal carcinoma and a metastatic carcinoma to the skin is a challenging yet critical task for dermatologists and pathologists. Carcinomas that have metastasized to the skin are a sign of widespread systemic involvement and poor prognosis, while primary adnexal carcinomas tend to progress with an indolent clinical course. Although many patients with cutaneous metastases from an internal primary neoplasm can expect a median survival of no more than 12 months,¹ patients with primary adnexal carcinomas are reported to have a 5-year survival rate of 95.5% for localized disease and 85% with spread to regional lymph nodes.² We report a case of multiple cutaneous neoplasms of unknown primary origin in a 71-year-old man and describe our approach to identification of the possible primary site as well as management of the disease.  

Case Report

A 71-year-old man initially presented to his primary physician for evaluation of a mass on the left side of the neck of 3 months' duration. On physical examination, a firm 2.5×3.0-cm nodule was noted at the anterior border of the trapezius muscle. Palpation of the thyroid revealed an additional right-sided nodule. The submandibular and parotid glands were unremarkable to palpation. The patient was referred to general surgery for biopsy, which revealed an infiltrating, moderately differentiated adenocarcinoma with extensive lymphatic permeation. Immunohistochemical staining for cytokeratin (CK) 7 was positive, while CK20 and thyroid transcription factor 1 were negative. A positron emission tomography/computed tomography (CT) fusion scan demonstrated 3 areas of enhanced uptake: one in the right side of the thyroid, a second corresponding to the mass on the left side of the neck at the level of the trapezius muscle, and a third in the left masseter muscle. Surgical excision with negative margins with possible chemotherapy was recommended; however, the patient declined treatment and was lost to follow-up until 2 years later when he presented to his primary physician with an additional lesion on his scalp.

Four years after the biopsy, the patient presented to the dermatology department with additional tumor nodules including a 4-cm, annular, indurated, focally eroded plaque on the left side of the lateral neck (Figure 1); 3 separate 1-cm nodules on the right side of the lateral neck; and an ulcerated, crusted, 10×8-cm plaque on the posterior aspect of the scalp. Despite the extensive lesions, the patient remained in good health and reported no recent weight loss or signs or symptoms of systemic involvement. The posterior scalp lesion, which developed 2 years after the initial appearance of the mass on the neck and was thought to represent a possible metastasis of the tumor, was biopsied and showed diffuse infiltration of the dermis by poorly differentiated tumor cells with vacuolated cytoplasm arranged in nests and cords and sometimes in a single-file arrangement (Figure 2). A CT scan demonstrated pretracheal lymphadenopathy as well as small intraparenchymal and subpleural pulmonary nodules throughout both lung fields.

Another scalp biopsy was taken. Tumor cells were negative on mucicarmine staining. Additional immunohistochemical staining, including a periodic acid-Schiff stain with diastase digestion for epithelial mucin revealed minimal luminal positivity. Immunostaining was positive for CK7, carcinoembryonic antigen, CD15, estrogen receptor, progesterone receptor, gross cystic disease fluid protein 15 (GCDFP-15), and mammaglobin, and negative for CK20, podoplanin, thyroid transcription factor 1, S-100 protein, p63, and prostate specific antigen. ERBB2 (formerly HER2/neu) staining was negative according to fluorescence in situ hybridization analysis. Tumor cells showed a Ki-67 nuclear proliferation index of greater than 50%, indicating progression to aggressive carcinoma. 

Based on the histological and immunochemical studies, the differential diagnosis included primary cutaneous apocrine carcinoma versus breast carcinoma; however, the prolonged clinical progression of these lesions favored a primary cutaneous adnexal tumor over a metastatic adenocarcinoma. Nevertheless, despite the initially indolent growth of the lesions over the first 5 years, the Ki-67 proliferation index and presence of widespread metastases on the posterior scalp indicated progression to an aggressive carcinoma. Chemotherapy was recommended as the treatment of choice. At his most recent follow-up visit 4 months later, the patient chose to begin treatment with tamoxifen and refused other treatment options.

Comment

The distinction between primary adnexal and metastatic adenocarcinomas of the skin is challenging both clinically and histologically. Some pathologists have argued that metastatic breast carcinomas and primary cutaneous apocrine carcinomas are essentially indistinguishable.³ Patients with cutaneous metastases, which occur in approximately 5.3% of all malignancies,⁴ typically can expect survival of no more than 12 months from the time of detection.¹ In contrast, primary apocrine carcinomas of the skin, though much less common, carry a remarkably better prognosis, with 5-year relative survival rates of 95.5% and 85.5% reported for patients with localized disease and spread to regional lymph nodes, respectively.²

Fewer than 100 cases of primary cutaneous adnexal (apocrine) carcinomas have been reported overall, with the earliest known report dating back to 1944.⁵ According to the literature, primary apocrine carcinomas were diagnosed at a median age of 66 years and were slightly more common in females than males.^2,6 Apocrine carcinomas were seen most frequently on the head, neck, and trunk,² generally presenting in the form of asymptomatic nodules or plaques of 2 to 3 cm in size, with gradual progression occurring over months to years.⁶ Approximately 40% of patients have been reported with positive regional lymph nodes at diagnosis. Treatment of apocrine carcinoma typically has involved local excision with clear margins with or without lymph node dissection. Chemotherapy and radiation therapy have shown no proven benefit.⁷

Currently, there is no standardized approach to evaluating patients with possible cutaneous metastasis versus primary cutaneous adnexal carcinomas. Imaging studies such as mammography and abdominal CT typically reveal an internal primary cancer in one-third of patients. However, additional studies such as gastrointestinal radiography, chest and pelvic CT, barium enema, and intravenous pyelogram have shown to be of limited value.⁸ Although specificity and sensitivity of immunohistochemistry is limited, a number of immunomarkers, including CK7 and CK20, are routinely studied to narrow the differential diagnosis of a cutaneous neoplasm of unclear origin. Urothelial, gastric, colorectal, and pancreatic carcinomas generally are positive for CK20; CK7-positive adenocarcinomas include salivary, non-small cell lung, breast, ovarian, pancreatic, endometrial, and transitional cell adenocarcinomas. Carcinomas negative for both CK7 and CK20 include colorectal, hepatocellular, renal cell, prostate, and squamous cell carcinoma of the lung. 

The presence of positive staining for estrogen and progesterone receptors as well as GCDFP-15 and mammaglobin raised the possibility of primary breast adenocarcinoma in our patient, but given that these markers can be positive in primary cutaneous adnexal tumors, immunohistochemistry results were not able to provide a definitive primary site. The overall staining pattern was nearly identical to 26 cases of primary cutaneous cribriform apocrine carcinoma, which was found to be positive for CK7 and carcinoembryonic antigen, and negative for CK20 and S-100. The only difference was in GCDFP-15 staining, which was positive in our case and negative in the cases of cribriform apocrine carcinoma.⁹ Histologic features favoring a primary apocrine origin include normal apocrine glands in the vicinity, glandular structures with decapitation secretion high in the dermis, and intracytoplasmic iron granules.¹⁰ Additionally, positive estrogen receptor staining appears to be much more common in apocrine carcinomas (5/10) than in eccrine carcinomas (1/7).¹¹

A number of other markers have been investigated for possible diagnostic utility for distinction between primary adnexal carcinomas and metastatic adenocarcinomas. The nuclear transcription factor p63, which plays a role in keratinocyte differentiation, is preferentially expressed in a number of primary adnexal carcinomas and is purported to be the most sensitive marker overall, with a sensitivity of 78% to 91%.^12-14 However, p63 has shown incomplete specificity for primary adnexal neoplasms, having been reported as positive in 11% to 22% of adenocarcinomas metastatic to skin.^15-18 Nestin and CK15, which are expressed in hair follicle progenitor cells, also are potential specific markers for some primary adnexal lesions, specifically eccrine carcinoma, porocarcinoma, hidradenocarcinoma, and microcystic adnexal carcinoma; however, in one report, none of the apocrine carcinomas were positive for p63, cytokeratin 15, or D2-40.¹⁹ Thus, while markers for some primary adnexal neoplasms are emerging, specific tests at the immunohistochemical level for the apocrine carcinoma subgroup are still lacking.

Conclusion

In summary, a conclusive distinction between primary cutaneous apocrine carcinoma and metastatic adenocarcinoma to the skin remains challenging. Although new markers provide more specificity and sensitivity for neoplasms of eccrine origin, these markers do not appear to differentiate between primary apocrine carcinoma and metastatic breast carcinoma. In this case, as in other recent reports, diagnosis remained dependent on the clinical course of the patient. Although considerable progress has been made regarding immunohistochemical analysis of these cases, additional markers, especially ones more specific for primary skin cancers with apocrine differentiation, are still needed.

Keratoacanthomas (KAs) are rapidly growing tumors most prominently found on sun-exposed areas of the skin. The normal progression of a KA is to show rapid growth followed by spontaneous resolution.¹ Most KAs are solitary; however, there are several variants of multiple KAs including the familial Ferguson-Smith type, Gryzbowski syndrome (generalized eruptive KAs), KA centrifugum marginatum, Muir-Torre syndrome, and xeroderma pigmentosum.^2-4 Keratoacanthomas also may develop in areas of trauma, including burns, laser treatment, radiation, and surgical margins from excisional biopsies or skin grafting.⁵ Treatment of multiple KAs can be difficult due to a potentially large field size and number of lesions.⁶ We present a case of multiple KAs developing both in the surgical margins and de novo that responded dramatically to treatment with intralesional methotrexate (MTX).

Case Report

A 55-year-old man with a history of a surgically treated squamous cell carcinoma (SCC) on the anterior aspect of the right leg developed multiple nodules involving the surgical scar. He previously underwent Mohs micrographic surgery (MMS); within a month after the second surgery the patient noticed increased pruritus along with scaly pink changes at the site of the surgical scar.

One month prior to presentation, biopsies from the anterior aspect of the right leg demonstrated well-differentiated SCC and he was subsequently treated with MMS; however, examination 1 month after MMS revealed an 11×7-cm indurated plaque with multiple nodules ranging from 1 to 2 cm near the periphery of the plaque with central atrophy and scarring, reminiscent of KA centrifugum marginatum (Figure, A). In a similar fashion, an 8×5-cm plaque composed of 7 nodular areas was noted on the posterior aspect of the right leg (Figure, B). The patient denied any history of trauma to this area. There was no palpable regional lymphadenopathy and the remainder of the skin examination was normal, except for signs of venous stasis in both legs.

Based on the location and morphology of the lesions, the clinical presentation was consistent with multiple KAs. Histologic examination from punch biopsies taken from the plaque's periphery demonstrated well-differentiated SCC (KA type), as well as a lichenoid inflammatory process, epidermal hyperplasia, and cystic and endophytic squamous proliferation suggestive of hypertrophic lichen planus (HLP).

In consideration of the size and number of the lesions as well as the prolonged wound healing with prior surgery, the patient consented to treatment with intralesional MTX (1 mL of 12.5 mg/mL every 2 weeks) rather than undergoing further surgery. The MTX injection was distributed between the lesions on the anterior and posterior aspects of the lower right leg. At each injection session, the size, thickness, and nodularity of the tumor decreased with markedly less pruritus and symptomatic relief was achieved. After 3 injection sessions, resulting in a total of 3 mL of 12.5 mg/mL of MTX, biopsies were taken from the residual atrophic scar on the anterior aspect of the right leg and the remaining 3 papules on the posterior aspect of the right leg to rule out HLP and invasive SCC. The pathology report commented on the presence of prurigo nodules without any evidence of SCC.

At 3-month follow-up, the patient demonstrated no new lesions or recurrence (Figure, C and D). The right leg continued to heal with scarring and postinflammatory pigmentary changes. The patient was monitored for recurrence and to determine the diagnosis of HLP.

Comment

We report the development of multiple KAs arising both from within surgical margins and de novo, and resolution with intralesional MTX. Keratoacanthomas, especially various KA types, have been observed to develop due to various types of trauma, including sites of surgical scars, lichen planus, tattoos, thermal burns, radiation, and discoid lupus erythematosus, and within skin grafts and donor sites.^5-19

Hypertrophic lichen planus is a chronic variant of lichen planus that often is found on the pretibial areas of the lower legs.¹³ Both SCC and reactive KAs have been observed to develop within lesions of HLP.¹⁴ Our pathologist commented on the presence of a lichenoid infiltrate with necrotic keratinocytes and epidermal hyperplasia suspicious for HLP, with a small focus of cystic and endophytic squamous proliferation. The latter lacked notable atypia or an invasive component and could represent an irritated infundibular cyst versus an early evolving KA.

The lichenoid inflammation is suspicious for HLP, which has been associated with eruptive KAs^13-16 and may have contributed to the development of persistent KAs in our patient, both in sites of surgical scars (the anterior aspect of the leg) and in uninvolved skin (the posterior aspect of the leg). Trauma from the prior surgery may have stimulated a local inflammatory response and, if coupled with a preexisting underlying chronic inflammatory condition such as HLP, may have triggered the development of new lesions on the posterior leg. Skin pathergy reactions also are caused by an upregulated inflammatory response, which is reduced with immunosuppressive agents such as MTX.¹²

In our patient, there was both an isotopic and isomorphic response. The term isotopic response refers to the occurrence of a new skin disorder at the site of another unrelated and already healed skin disease. It was first defined by Wolf and Wolf²⁰ in 1985 and hence is also known as Wolf isotopic response. The isotopic response in our patient occurred in the setting of lichen planus. The isomorphic response indicates the appearance of typical skin lesions of an existing dermatosis at sites of other skin injuries.

Initially, we thought the patient had recurrence of SCC, but with the rapid development of multiple lesions, the diagnosis of multiple KAs was more likely. Kimyai-Asadi et al⁸ demonstrated that surgical trauma can precede the development of KAs, as they reported a patient who developed a KA at an excision site. Tamir et al⁷ reported the simultaneous appearance of KAs in burn scars and skin graft donor sites 4 months after a 40% total body surface area burn. Hamilton et al¹¹ described surgical trauma from a split-skin graft donor site as a trigger for the onset of a KA.

Multiple treatment alternatives exist for KAs, with the standard of care for large or high-risk KAs being excisional surgery^21,22; however, other approaches may need to be considered in certain cases, such as with multiple KAs in which lesions may be large and extensive, thereby yielding poor cosmetic outcomes, or with increased surgical risk.²³ Furthermore, multiple KAs that develop in the setting of surgical scars require special consideration. Topical 5-fluorouracil, various systemic and intralesional agents (eg, retinoids, interferon, bleomycin, MTX), laser therapy, electrodesiccation and curettage, radiotherapy, and photodynamic therapy all have been reported as methods employed for the treatment of KA.^23-27 Goldberg et al⁵ reported cases of resolution of eruptive KAs arising in both surgical and nonsurgical sites with a combination of deep shave excision, MMS, curettage and desiccation, and oral isotretinoin.

For our patient, we opted for treatment with intralesional MTX, both due to its effectiveness for solitary KAs and reasonably decreased risk of morbidity compared to surgical excision of regions of the pretibial calves. Treatment with MTX would not have been attempted if there was any clinical doubt that the lesions were not the well-differentiated KA type. Also, we had a low threshold for discontinuing therapy and reverting to MMS treatment if any of the lesions displayed a paradoxical growth post-MTX treatment or failed to respond after 3 treatments. Intralesional MTX is less invasive, relatively inexpensive, and a treatment modality with decreased morbidity for KAs, especially for multiple KAs. It should be considered as a potential alternative to surgery in such cases.^23-27

Keratoacanthomas (KAs) are rapidly growing tumors most prominently found on sun-exposed areas of the skin. The normal progression of a KA is to show rapid growth followed by spontaneous resolution.¹ Most KAs are solitary; however, there are several variants of multiple KAs including the familial Ferguson-Smith type, Gryzbowski syndrome (generalized eruptive KAs), KA centrifugum marginatum, Muir-Torre syndrome, and xeroderma pigmentosum.^2-4 Keratoacanthomas also may develop in areas of trauma, including burns, laser treatment, radiation, and surgical margins from excisional biopsies or skin grafting.⁵ Treatment of multiple KAs can be difficult due to a potentially large field size and number of lesions.⁶ We present a case of multiple KAs developing both in the surgical margins and de novo that responded dramatically to treatment with intralesional methotrexate (MTX).

Case Report

A 55-year-old man with a history of a surgically treated squamous cell carcinoma (SCC) on the anterior aspect of the right leg developed multiple nodules involving the surgical scar. He previously underwent Mohs micrographic surgery (MMS); within a month after the second surgery the patient noticed increased pruritus along with scaly pink changes at the site of the surgical scar.

One month prior to presentation, biopsies from the anterior aspect of the right leg demonstrated well-differentiated SCC and he was subsequently treated with MMS; however, examination 1 month after MMS revealed an 11×7-cm indurated plaque with multiple nodules ranging from 1 to 2 cm near the periphery of the plaque with central atrophy and scarring, reminiscent of KA centrifugum marginatum (Figure, A). In a similar fashion, an 8×5-cm plaque composed of 7 nodular areas was noted on the posterior aspect of the right leg (Figure, B). The patient denied any history of trauma to this area. There was no palpable regional lymphadenopathy and the remainder of the skin examination was normal, except for signs of venous stasis in both legs.

Based on the location and morphology of the lesions, the clinical presentation was consistent with multiple KAs. Histologic examination from punch biopsies taken from the plaque's periphery demonstrated well-differentiated SCC (KA type), as well as a lichenoid inflammatory process, epidermal hyperplasia, and cystic and endophytic squamous proliferation suggestive of hypertrophic lichen planus (HLP).

In consideration of the size and number of the lesions as well as the prolonged wound healing with prior surgery, the patient consented to treatment with intralesional MTX (1 mL of 12.5 mg/mL every 2 weeks) rather than undergoing further surgery. The MTX injection was distributed between the lesions on the anterior and posterior aspects of the lower right leg. At each injection session, the size, thickness, and nodularity of the tumor decreased with markedly less pruritus and symptomatic relief was achieved. After 3 injection sessions, resulting in a total of 3 mL of 12.5 mg/mL of MTX, biopsies were taken from the residual atrophic scar on the anterior aspect of the right leg and the remaining 3 papules on the posterior aspect of the right leg to rule out HLP and invasive SCC. The pathology report commented on the presence of prurigo nodules without any evidence of SCC.

At 3-month follow-up, the patient demonstrated no new lesions or recurrence (Figure, C and D). The right leg continued to heal with scarring and postinflammatory pigmentary changes. The patient was monitored for recurrence and to determine the diagnosis of HLP.

Comment

We report the development of multiple KAs arising both from within surgical margins and de novo, and resolution with intralesional MTX. Keratoacanthomas, especially various KA types, have been observed to develop due to various types of trauma, including sites of surgical scars, lichen planus, tattoos, thermal burns, radiation, and discoid lupus erythematosus, and within skin grafts and donor sites.^5-19

Hypertrophic lichen planus is a chronic variant of lichen planus that often is found on the pretibial areas of the lower legs.¹³ Both SCC and reactive KAs have been observed to develop within lesions of HLP.¹⁴ Our pathologist commented on the presence of a lichenoid infiltrate with necrotic keratinocytes and epidermal hyperplasia suspicious for HLP, with a small focus of cystic and endophytic squamous proliferation. The latter lacked notable atypia or an invasive component and could represent an irritated infundibular cyst versus an early evolving KA.

The lichenoid inflammation is suspicious for HLP, which has been associated with eruptive KAs^13-16 and may have contributed to the development of persistent KAs in our patient, both in sites of surgical scars (the anterior aspect of the leg) and in uninvolved skin (the posterior aspect of the leg). Trauma from the prior surgery may have stimulated a local inflammatory response and, if coupled with a preexisting underlying chronic inflammatory condition such as HLP, may have triggered the development of new lesions on the posterior leg. Skin pathergy reactions also are caused by an upregulated inflammatory response, which is reduced with immunosuppressive agents such as MTX.¹²

In our patient, there was both an isotopic and isomorphic response. The term isotopic response refers to the occurrence of a new skin disorder at the site of another unrelated and already healed skin disease. It was first defined by Wolf and Wolf²⁰ in 1985 and hence is also known as Wolf isotopic response. The isotopic response in our patient occurred in the setting of lichen planus. The isomorphic response indicates the appearance of typical skin lesions of an existing dermatosis at sites of other skin injuries.

Initially, we thought the patient had recurrence of SCC, but with the rapid development of multiple lesions, the diagnosis of multiple KAs was more likely. Kimyai-Asadi et al⁸ demonstrated that surgical trauma can precede the development of KAs, as they reported a patient who developed a KA at an excision site. Tamir et al⁷ reported the simultaneous appearance of KAs in burn scars and skin graft donor sites 4 months after a 40% total body surface area burn. Hamilton et al¹¹ described surgical trauma from a split-skin graft donor site as a trigger for the onset of a KA.

Multiple treatment alternatives exist for KAs, with the standard of care for large or high-risk KAs being excisional surgery^21,22; however, other approaches may need to be considered in certain cases, such as with multiple KAs in which lesions may be large and extensive, thereby yielding poor cosmetic outcomes, or with increased surgical risk.²³ Furthermore, multiple KAs that develop in the setting of surgical scars require special consideration. Topical 5-fluorouracil, various systemic and intralesional agents (eg, retinoids, interferon, bleomycin, MTX), laser therapy, electrodesiccation and curettage, radiotherapy, and photodynamic therapy all have been reported as methods employed for the treatment of KA.^23-27 Goldberg et al⁵ reported cases of resolution of eruptive KAs arising in both surgical and nonsurgical sites with a combination of deep shave excision, MMS, curettage and desiccation, and oral isotretinoin.

For our patient, we opted for treatment with intralesional MTX, both due to its effectiveness for solitary KAs and reasonably decreased risk of morbidity compared to surgical excision of regions of the pretibial calves. Treatment with MTX would not have been attempted if there was any clinical doubt that the lesions were not the well-differentiated KA type. Also, we had a low threshold for discontinuing therapy and reverting to MMS treatment if any of the lesions displayed a paradoxical growth post-MTX treatment or failed to respond after 3 treatments. Intralesional MTX is less invasive, relatively inexpensive, and a treatment modality with decreased morbidity for KAs, especially for multiple KAs. It should be considered as a potential alternative to surgery in such cases.^23-27

Keratoacanthomas (KAs) are rapidly growing tumors most prominently found on sun-exposed areas of the skin. The normal progression of a KA is to show rapid growth followed by spontaneous resolution.¹ Most KAs are solitary; however, there are several variants of multiple KAs including the familial Ferguson-Smith type, Gryzbowski syndrome (generalized eruptive KAs), KA centrifugum marginatum, Muir-Torre syndrome, and xeroderma pigmentosum.^2-4 Keratoacanthomas also may develop in areas of trauma, including burns, laser treatment, radiation, and surgical margins from excisional biopsies or skin grafting.⁵ Treatment of multiple KAs can be difficult due to a potentially large field size and number of lesions.⁶ We present a case of multiple KAs developing both in the surgical margins and de novo that responded dramatically to treatment with intralesional methotrexate (MTX).

Case Report

A 55-year-old man with a history of a surgically treated squamous cell carcinoma (SCC) on the anterior aspect of the right leg developed multiple nodules involving the surgical scar. He previously underwent Mohs micrographic surgery (MMS); within a month after the second surgery the patient noticed increased pruritus along with scaly pink changes at the site of the surgical scar.

One month prior to presentation, biopsies from the anterior aspect of the right leg demonstrated well-differentiated SCC and he was subsequently treated with MMS; however, examination 1 month after MMS revealed an 11×7-cm indurated plaque with multiple nodules ranging from 1 to 2 cm near the periphery of the plaque with central atrophy and scarring, reminiscent of KA centrifugum marginatum (Figure, A). In a similar fashion, an 8×5-cm plaque composed of 7 nodular areas was noted on the posterior aspect of the right leg (Figure, B). The patient denied any history of trauma to this area. There was no palpable regional lymphadenopathy and the remainder of the skin examination was normal, except for signs of venous stasis in both legs.

Based on the location and morphology of the lesions, the clinical presentation was consistent with multiple KAs. Histologic examination from punch biopsies taken from the plaque's periphery demonstrated well-differentiated SCC (KA type), as well as a lichenoid inflammatory process, epidermal hyperplasia, and cystic and endophytic squamous proliferation suggestive of hypertrophic lichen planus (HLP).

In consideration of the size and number of the lesions as well as the prolonged wound healing with prior surgery, the patient consented to treatment with intralesional MTX (1 mL of 12.5 mg/mL every 2 weeks) rather than undergoing further surgery. The MTX injection was distributed between the lesions on the anterior and posterior aspects of the lower right leg. At each injection session, the size, thickness, and nodularity of the tumor decreased with markedly less pruritus and symptomatic relief was achieved. After 3 injection sessions, resulting in a total of 3 mL of 12.5 mg/mL of MTX, biopsies were taken from the residual atrophic scar on the anterior aspect of the right leg and the remaining 3 papules on the posterior aspect of the right leg to rule out HLP and invasive SCC. The pathology report commented on the presence of prurigo nodules without any evidence of SCC.

At 3-month follow-up, the patient demonstrated no new lesions or recurrence (Figure, C and D). The right leg continued to heal with scarring and postinflammatory pigmentary changes. The patient was monitored for recurrence and to determine the diagnosis of HLP.

Comment

We report the development of multiple KAs arising both from within surgical margins and de novo, and resolution with intralesional MTX. Keratoacanthomas, especially various KA types, have been observed to develop due to various types of trauma, including sites of surgical scars, lichen planus, tattoos, thermal burns, radiation, and discoid lupus erythematosus, and within skin grafts and donor sites.^5-19

Hypertrophic lichen planus is a chronic variant of lichen planus that often is found on the pretibial areas of the lower legs.¹³ Both SCC and reactive KAs have been observed to develop within lesions of HLP.¹⁴ Our pathologist commented on the presence of a lichenoid infiltrate with necrotic keratinocytes and epidermal hyperplasia suspicious for HLP, with a small focus of cystic and endophytic squamous proliferation. The latter lacked notable atypia or an invasive component and could represent an irritated infundibular cyst versus an early evolving KA.

The lichenoid inflammation is suspicious for HLP, which has been associated with eruptive KAs^13-16 and may have contributed to the development of persistent KAs in our patient, both in sites of surgical scars (the anterior aspect of the leg) and in uninvolved skin (the posterior aspect of the leg). Trauma from the prior surgery may have stimulated a local inflammatory response and, if coupled with a preexisting underlying chronic inflammatory condition such as HLP, may have triggered the development of new lesions on the posterior leg. Skin pathergy reactions also are caused by an upregulated inflammatory response, which is reduced with immunosuppressive agents such as MTX.¹²

In our patient, there was both an isotopic and isomorphic response. The term isotopic response refers to the occurrence of a new skin disorder at the site of another unrelated and already healed skin disease. It was first defined by Wolf and Wolf²⁰ in 1985 and hence is also known as Wolf isotopic response. The isotopic response in our patient occurred in the setting of lichen planus. The isomorphic response indicates the appearance of typical skin lesions of an existing dermatosis at sites of other skin injuries.

Initially, we thought the patient had recurrence of SCC, but with the rapid development of multiple lesions, the diagnosis of multiple KAs was more likely. Kimyai-Asadi et al⁸ demonstrated that surgical trauma can precede the development of KAs, as they reported a patient who developed a KA at an excision site. Tamir et al⁷ reported the simultaneous appearance of KAs in burn scars and skin graft donor sites 4 months after a 40% total body surface area burn. Hamilton et al¹¹ described surgical trauma from a split-skin graft donor site as a trigger for the onset of a KA.

Multiple treatment alternatives exist for KAs, with the standard of care for large or high-risk KAs being excisional surgery^21,22; however, other approaches may need to be considered in certain cases, such as with multiple KAs in which lesions may be large and extensive, thereby yielding poor cosmetic outcomes, or with increased surgical risk.²³ Furthermore, multiple KAs that develop in the setting of surgical scars require special consideration. Topical 5-fluorouracil, various systemic and intralesional agents (eg, retinoids, interferon, bleomycin, MTX), laser therapy, electrodesiccation and curettage, radiotherapy, and photodynamic therapy all have been reported as methods employed for the treatment of KA.^23-27 Goldberg et al⁵ reported cases of resolution of eruptive KAs arising in both surgical and nonsurgical sites with a combination of deep shave excision, MMS, curettage and desiccation, and oral isotretinoin.

For our patient, we opted for treatment with intralesional MTX, both due to its effectiveness for solitary KAs and reasonably decreased risk of morbidity compared to surgical excision of regions of the pretibial calves. Treatment with MTX would not have been attempted if there was any clinical doubt that the lesions were not the well-differentiated KA type. Also, we had a low threshold for discontinuing therapy and reverting to MMS treatment if any of the lesions displayed a paradoxical growth post-MTX treatment or failed to respond after 3 treatments. Intralesional MTX is less invasive, relatively inexpensive, and a treatment modality with decreased morbidity for KAs, especially for multiple KAs. It should be considered as a potential alternative to surgery in such cases.^23-27

As survival rates among pediatric organ transplant recipients increase, so do the rates of cutaneous malignancies later in life for this population, who are at a greater risk for skin cancers that include nonmelanoma skin cancers (NMSCs), melanoma, Kaposi sarcoma, and anogenital carcinoma, according to the authors of a literature review.

In studies, skin cancers account for 13%-55% of all cancers in pediatric organ transplant recipients (POTRs), according to Alexander L. Fogel of Stanford (Calif.) University and his coauthors. The review article provides an update on this topic, as well as information on the prevention and management of skin cancers in this population, and the differences between this group and adult organ transplant recipients (AOTRs).

This article was updated 12/8/16. 

[email protected]

On Twitter @whitneymcknight

As survival rates among pediatric organ transplant recipients increase, so do the rates of cutaneous malignancies later in life for this population, who are at a greater risk for skin cancers that include nonmelanoma skin cancers (NMSCs), melanoma, Kaposi sarcoma, and anogenital carcinoma, according to the authors of a literature review.

In studies, skin cancers account for 13%-55% of all cancers in pediatric organ transplant recipients (POTRs), according to Alexander L. Fogel of Stanford (Calif.) University and his coauthors. The review article provides an update on this topic, as well as information on the prevention and management of skin cancers in this population, and the differences between this group and adult organ transplant recipients (AOTRs).

This article was updated 12/8/16. 

[email protected]

On Twitter @whitneymcknight

As survival rates among pediatric organ transplant recipients increase, so do the rates of cutaneous malignancies later in life for this population, who are at a greater risk for skin cancers that include nonmelanoma skin cancers (NMSCs), melanoma, Kaposi sarcoma, and anogenital carcinoma, according to the authors of a literature review.

In studies, skin cancers account for 13%-55% of all cancers in pediatric organ transplant recipients (POTRs), according to Alexander L. Fogel of Stanford (Calif.) University and his coauthors. The review article provides an update on this topic, as well as information on the prevention and management of skin cancers in this population, and the differences between this group and adult organ transplant recipients (AOTRs).

This article was updated 12/8/16. 

[email protected]

On Twitter @whitneymcknight

Immunosuppressive treatment with azathioprine may be associated with an increased risk of squamous cell carcinoma in organ transplant recipients, but does not appear to increase the risk of basal cell carcinoma or keratinocyte cancers overall, according to a systematic review and meta-analysis of 27 studies.

While immunosuppressive agents generally are known to contribute to an increased risk of skin carcinogenesis, azathioprine – a purine antimetabolite immunosuppressant – is thought to add to this increase through its photosensitizing effects and the accumulation of mutagenic reactive oxygen species when exposed to UVA.

To address conflicting data on whether azathioprine increases the risk of skin cancer, the authors conducted the analysis of 27 studies (23 cohort studies, 1 randomized study, and 3 case control studies) published between 1996 and 2011, which evaluated skin cancer risk associated with azathioprine in people who received an organ transplant from 1963 to 2011, at a median age of 38-54 years.

In the studies that evaluated the risk of squamous cell carcinoma, risk was elevated by 56% among patients treated with azathioprine (95% CI 1.11-2.18, P less than .001), but estimates ranged from 0.64 to 8.64. The risk was sevenfold higher in two case-control studies combined, but was not significant in eight cohort studies, reported Zainab Jiyad, MD, of QIMR Berghofer Medical Research Institute in Brisbane, Australia, and St. George’s University of London, and coauthors. They noted that there was significant heterogeneity between the studies, probably because of differences in study design, organ transplant type, and period of transplantation (Am J Transplant. 2016 Dec;16[12]:3490-503).

“Despite the substantial heterogeneity, which would tend to dilute the observed summary risk estimate, a significant effect of azathioprine was detected,” they added. “Thus, we acknowledge that our summary estimate may be a conservative estimate of the risk associated with azathioprine.”

The subgroup analysis comparing the risk among kidney and heart transplant recipients showed the increased risk of squamous cell carcinoma was significant among kidney transplant recipients but not among heart transplant recipients.

Among the six cohort studies that evaluated the risk of basal cell carcinoma, the risk was increased in four studies, while two suggested that azathioprine was actually protective against it. When the studies were pooled, the estimated risk was 0.96.

Similarly, when researchers looked at studies of keratinocyte cancers (the combined risk of squamous cell and basal cell cancers), there was no significant association with overall risk of KC.

Older age and transplantation, fair skin type, high sun exposure, childhood sunburn, a history of skin cancer, and rejection episodes in the first year of transplantation were all risk factors for developing squamous cell carcinoma. Therefore, avoiding azathioprine in organ transplant recipients “with one or more of these risk factors may help reduce the future risk” of squamous cell cancer, they wrote.

The authors added that more high quality studies were needed and that studies should evaluate the risk of squamous cell and basal cell cancer separately, because of the apparent difference in risk.

No conflicts of interest were declared.

Immunosuppressive treatment with azathioprine may be associated with an increased risk of squamous cell carcinoma in organ transplant recipients, but does not appear to increase the risk of basal cell carcinoma or keratinocyte cancers overall, according to a systematic review and meta-analysis of 27 studies.

While immunosuppressive agents generally are known to contribute to an increased risk of skin carcinogenesis, azathioprine – a purine antimetabolite immunosuppressant – is thought to add to this increase through its photosensitizing effects and the accumulation of mutagenic reactive oxygen species when exposed to UVA.

To address conflicting data on whether azathioprine increases the risk of skin cancer, the authors conducted the analysis of 27 studies (23 cohort studies, 1 randomized study, and 3 case control studies) published between 1996 and 2011, which evaluated skin cancer risk associated with azathioprine in people who received an organ transplant from 1963 to 2011, at a median age of 38-54 years.

In the studies that evaluated the risk of squamous cell carcinoma, risk was elevated by 56% among patients treated with azathioprine (95% CI 1.11-2.18, P less than .001), but estimates ranged from 0.64 to 8.64. The risk was sevenfold higher in two case-control studies combined, but was not significant in eight cohort studies, reported Zainab Jiyad, MD, of QIMR Berghofer Medical Research Institute in Brisbane, Australia, and St. George’s University of London, and coauthors. They noted that there was significant heterogeneity between the studies, probably because of differences in study design, organ transplant type, and period of transplantation (Am J Transplant. 2016 Dec;16[12]:3490-503).

“Despite the substantial heterogeneity, which would tend to dilute the observed summary risk estimate, a significant effect of azathioprine was detected,” they added. “Thus, we acknowledge that our summary estimate may be a conservative estimate of the risk associated with azathioprine.”

The subgroup analysis comparing the risk among kidney and heart transplant recipients showed the increased risk of squamous cell carcinoma was significant among kidney transplant recipients but not among heart transplant recipients.

Among the six cohort studies that evaluated the risk of basal cell carcinoma, the risk was increased in four studies, while two suggested that azathioprine was actually protective against it. When the studies were pooled, the estimated risk was 0.96.

Similarly, when researchers looked at studies of keratinocyte cancers (the combined risk of squamous cell and basal cell cancers), there was no significant association with overall risk of KC.

Older age and transplantation, fair skin type, high sun exposure, childhood sunburn, a history of skin cancer, and rejection episodes in the first year of transplantation were all risk factors for developing squamous cell carcinoma. Therefore, avoiding azathioprine in organ transplant recipients “with one or more of these risk factors may help reduce the future risk” of squamous cell cancer, they wrote.

The authors added that more high quality studies were needed and that studies should evaluate the risk of squamous cell and basal cell cancer separately, because of the apparent difference in risk.

No conflicts of interest were declared.

Immunosuppressive treatment with azathioprine may be associated with an increased risk of squamous cell carcinoma in organ transplant recipients, but does not appear to increase the risk of basal cell carcinoma or keratinocyte cancers overall, according to a systematic review and meta-analysis of 27 studies.

While immunosuppressive agents generally are known to contribute to an increased risk of skin carcinogenesis, azathioprine – a purine antimetabolite immunosuppressant – is thought to add to this increase through its photosensitizing effects and the accumulation of mutagenic reactive oxygen species when exposed to UVA.

To address conflicting data on whether azathioprine increases the risk of skin cancer, the authors conducted the analysis of 27 studies (23 cohort studies, 1 randomized study, and 3 case control studies) published between 1996 and 2011, which evaluated skin cancer risk associated with azathioprine in people who received an organ transplant from 1963 to 2011, at a median age of 38-54 years.

In the studies that evaluated the risk of squamous cell carcinoma, risk was elevated by 56% among patients treated with azathioprine (95% CI 1.11-2.18, P less than .001), but estimates ranged from 0.64 to 8.64. The risk was sevenfold higher in two case-control studies combined, but was not significant in eight cohort studies, reported Zainab Jiyad, MD, of QIMR Berghofer Medical Research Institute in Brisbane, Australia, and St. George’s University of London, and coauthors. They noted that there was significant heterogeneity between the studies, probably because of differences in study design, organ transplant type, and period of transplantation (Am J Transplant. 2016 Dec;16[12]:3490-503).

“Despite the substantial heterogeneity, which would tend to dilute the observed summary risk estimate, a significant effect of azathioprine was detected,” they added. “Thus, we acknowledge that our summary estimate may be a conservative estimate of the risk associated with azathioprine.”

The subgroup analysis comparing the risk among kidney and heart transplant recipients showed the increased risk of squamous cell carcinoma was significant among kidney transplant recipients but not among heart transplant recipients.

Among the six cohort studies that evaluated the risk of basal cell carcinoma, the risk was increased in four studies, while two suggested that azathioprine was actually protective against it. When the studies were pooled, the estimated risk was 0.96.

Similarly, when researchers looked at studies of keratinocyte cancers (the combined risk of squamous cell and basal cell cancers), there was no significant association with overall risk of KC.

Older age and transplantation, fair skin type, high sun exposure, childhood sunburn, a history of skin cancer, and rejection episodes in the first year of transplantation were all risk factors for developing squamous cell carcinoma. Therefore, avoiding azathioprine in organ transplant recipients “with one or more of these risk factors may help reduce the future risk” of squamous cell cancer, they wrote.

The authors added that more high quality studies were needed and that studies should evaluate the risk of squamous cell and basal cell cancer separately, because of the apparent difference in risk.

No conflicts of interest were declared.

At the 19th Annual Mount Sinai Winter Symposium, Dr. Orit Markowitz provided an update on dermoscopy as a first-line noninvasive imaging modality for skin cancer screening and diagnosis along with reflectance confocal microscopy and dynamic optical coherence tomography. She explained how noninvasive imaging offers a more complete picture of lesions along with what is seen clinically and on pathology and discussed how it can help catch aggressive melanomas and other skin cancers at earlier stages. For these reasons, she emphasized that increased use of dermoscopy can be used to justify the need for regular skin cancer screenings. Finally, she discussed how noninvasive imaging can be used to guide dermatologists in performing optimal biposies of suspicious lesions.

At the 19th Annual Mount Sinai Winter Symposium, Dr. Orit Markowitz provided an update on dermoscopy as a first-line noninvasive imaging modality for skin cancer screening and diagnosis along with reflectance confocal microscopy and dynamic optical coherence tomography. She explained how noninvasive imaging offers a more complete picture of lesions along with what is seen clinically and on pathology and discussed how it can help catch aggressive melanomas and other skin cancers at earlier stages. For these reasons, she emphasized that increased use of dermoscopy can be used to justify the need for regular skin cancer screenings. Finally, she discussed how noninvasive imaging can be used to guide dermatologists in performing optimal biposies of suspicious lesions.

At the 19th Annual Mount Sinai Winter Symposium, Dr. Orit Markowitz provided an update on dermoscopy as a first-line noninvasive imaging modality for skin cancer screening and diagnosis along with reflectance confocal microscopy and dynamic optical coherence tomography. She explained how noninvasive imaging offers a more complete picture of lesions along with what is seen clinically and on pathology and discussed how it can help catch aggressive melanomas and other skin cancers at earlier stages. For these reasons, she emphasized that increased use of dermoscopy can be used to justify the need for regular skin cancer screenings. Finally, she discussed how noninvasive imaging can be used to guide dermatologists in performing optimal biposies of suspicious lesions.