Case Reports

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.

THE CASE

A 44-year-old woman with a 15-year history of type 2 diabetes sought care for a firm, non-tender mass in the medial lower quadrant of her right breast. She hadn’t experienced any skin changes or axillary lymphadenopathy. The patient had immigrated to California from Afghanistan 22 years earlier, at which time she was briefly married to an Afghan man suffering from a chronic cough.

Mammography revealed a 3.5 x 4 x 4 cm lesion at the chest wall, which was highly suspicious for carcinoma (FIGURES 1A AND 1B). Sonography showed a heterogenous hypoechoic and isoechoic mass with posterior acoustic enhancement (FIGURE 1C). An excisional biopsy was performed.

One week postoperatively, the patient presented to the emergency department for a worsening nonproductive cough that intensified when supine, and was associated with subscapular pleuritic pain. She denied fever or weight loss. Biopsy results were pending.

THE DIAGNOSIS

Chest x-rays revealed a large right pleural effusion that was presumed to be malignant (FIGURES 1D AND 1E). Thoracentesis yielded 1.5 liters of tea-colored exudate containing 2800 nucleated cells/mL—63% lymphocytes and 37% neutrophils—and a pleural fluid to serum protein ratio >0.5. Adenosine deaminase was <1 U/L. Fluid Gram stain, acid-fast bacillus (AFB) fluorescent antibody testing, AFB cultures, and cytology were negative. Computed tomography (CT) subsequently demonstrated recurrent effusion without hilar or mediastinal lymphadenopathy or pleural enhancement (FIGURE 1F).

Histologically, the breast mass showed caseating granulomatous inflammation (FIGURES 1G AND 1H). An AFB stain was negative. Polymerase chain reaction (PCR) performed on DNA extracted from the formalin-fixed, paraffin-embedded biopsy material was positive for Mycobacterium tuberculosis.¹ A CT-guided pleural biopsy showed only normal tissue. A follow-up tuberculin skin test (purified protein derivative [PPD]) yielded a 10-mm indurated reaction.

DISCUSSION

Granulomatous lesions, such as foreign body granuloma, idiopathic granulomatous mastitis (IGM), and sarcoidosis can mimic breast carcinoma.^2,3 IGM is associated with elevated prolactin (eg, pregnancy or oral contraceptive use) and is usually subareolar.² Infection, however, is also commonly subareolar. Sarcoidosis rarely exhibits unilateral pleural effusion and usually manifests with bilateral interstitial lung disease, hilar lymphadenopathy, and non-necrotizing granulomas.^3,4

M tuberculosis and other granulomatous infections may also feign breast cancer.^5-13 Breast TB, which is highly uncommon in the developed world, often demonstrates imaging similar to that which was seen in this case. Breast TB may appear nodular with ill-defined contours. Masses are sometimes attached to the chest wall and usually lack microcalcifications on mammography; they are also typically hypoechoic and heterogenous on ultrasound, often showing posterior enhancement.^5,7,8 Like other breast infections, tuberculosis may show cutaneous sinus tract formation, which is seen in about one-third of patients.^6,7 Alternatively, it may manifest as a diffuse mastitis with skin thickening and axillary lymphadenopathy.⁸

Primary breast TB without chest disease comprises up to 86% of mammary tuberculosis.^6,7 Infection may occur via contamination of the skin or nipple.^5-7 Lactation, pregnancy, and other causes of immunosuppression (especially human immunodeficiency virus) have been associated with an increased risk of breast infection.^6-8 This patient was at risk for immunosuppression from longstanding diabetes.¹⁴

Many patients from TB-endemic areas have received the bacille Calmette-Guerin (BCG) vaccine and may exhibit equivocal or false-positive PPD results. Because interferon-gamma release assay TB blood tests (eg, QuantiFERON-TB Gold or T-SPOT.TB) are not affected by BCG, they are not associated with false-positive repeat testing results.¹⁵

Biopsy is necessary to rule out malignancy and diagnose breast TB

A pleural fluid to serum protein ratio >0.5 is consistent with infection, but also with sarcoidosis or malignancy.^3,16 Elevated pleural fluid adenosine deaminase (>40 U/L) is sensitive, albeit nonspecific, for the presence of TB microorganisms. If a lymphocyte-dominant exudate is also present, however, its reliability greatly increases.^16,17 Increased pleural fluid interferon-gamma is also sensitive and specific for TB pleurisy.¹⁸ Culture, along with drug sensitivity testing, should be performed on all unexplained pleural effusions.

This case emphasizes the need for increased awareness of extrapulmonary TB by physicians in developed countries.

A biopsy is often required to diagnose breast TB and should be performed on all suspicious lesions to exclude malignancy.^5-7,9 AFB stains and cultures of aspirate fluids or tissue are often negative.^7,9 PCR or other nucleic acid amplification tests of sputum, body fluids, or biopsy material may be positive in culture-negative cases and can rapidly confirm M tuberculosis infection.^17,19 No testing modality offers 100% sensitivity or specificity; therefore, an additional confirmatory test is desirable.

Possible routes of transmission include activation of latent pulmonary tuberculosis and direct, lymphatic, or hematologic extension to the chest wall and breast.^5-7 In this patient, we believe that activation of a latent breast granuloma may have resulted in a secondary or “sympathetic” pleural effusion, possibly triggered by surgical manipulation. This is compatible with her negative pleural adenosine deaminase result, negative culture, absence of pulmonary parenchymal disease, and negative pleural biopsy. Although we conducted a PubMed search, reviewing material as far back as 1966, we were unable to find a previous case of apparent sympathetic effusion associated with breast TB.

Our patient was treated with daily oral isoniazid, rifabutin, pyrazinamide, and ethambutol for 2 months, followed by isoniazid and rifabutin for 4 months. She has been disease-free for over 10 years.

THE TAKEAWAY

We describe a rare case of breast TB mimicking carcinoma that was associated with unilateral pleural effusion in a woman who had emigrated from Afghanistan. Patients at particular risk for breast TB include immigrants from endemic regions—especially parous females,^6,7 those with a history of TB contacts, and those who are immunosuppressed.⁸ This case emphasizes the need for increased awareness of extrapulmonary TB by physicians in developed countries.

ACKNOWLEDGEMENTS
The authors thank Drs. Margie Scott, Harpreet Dhillon, Samir Vora, Todd Williams, Jeffrey Hawley, and Mr. Sergio Landeros. This report is dedicated to the memory of our friend and colleague in medicine, Dr. Jeanie Care Gillinta.

THE CASE

A 44-year-old woman with a 15-year history of type 2 diabetes sought care for a firm, non-tender mass in the medial lower quadrant of her right breast. She hadn’t experienced any skin changes or axillary lymphadenopathy. The patient had immigrated to California from Afghanistan 22 years earlier, at which time she was briefly married to an Afghan man suffering from a chronic cough.

Mammography revealed a 3.5 x 4 x 4 cm lesion at the chest wall, which was highly suspicious for carcinoma (FIGURES 1A AND 1B). Sonography showed a heterogenous hypoechoic and isoechoic mass with posterior acoustic enhancement (FIGURE 1C). An excisional biopsy was performed.

One week postoperatively, the patient presented to the emergency department for a worsening nonproductive cough that intensified when supine, and was associated with subscapular pleuritic pain. She denied fever or weight loss. Biopsy results were pending.

THE DIAGNOSIS

Chest x-rays revealed a large right pleural effusion that was presumed to be malignant (FIGURES 1D AND 1E). Thoracentesis yielded 1.5 liters of tea-colored exudate containing 2800 nucleated cells/mL—63% lymphocytes and 37% neutrophils—and a pleural fluid to serum protein ratio >0.5. Adenosine deaminase was <1 U/L. Fluid Gram stain, acid-fast bacillus (AFB) fluorescent antibody testing, AFB cultures, and cytology were negative. Computed tomography (CT) subsequently demonstrated recurrent effusion without hilar or mediastinal lymphadenopathy or pleural enhancement (FIGURE 1F).

Histologically, the breast mass showed caseating granulomatous inflammation (FIGURES 1G AND 1H). An AFB stain was negative. Polymerase chain reaction (PCR) performed on DNA extracted from the formalin-fixed, paraffin-embedded biopsy material was positive for Mycobacterium tuberculosis.¹ A CT-guided pleural biopsy showed only normal tissue. A follow-up tuberculin skin test (purified protein derivative [PPD]) yielded a 10-mm indurated reaction.

DISCUSSION

Granulomatous lesions, such as foreign body granuloma, idiopathic granulomatous mastitis (IGM), and sarcoidosis can mimic breast carcinoma.^2,3 IGM is associated with elevated prolactin (eg, pregnancy or oral contraceptive use) and is usually subareolar.² Infection, however, is also commonly subareolar. Sarcoidosis rarely exhibits unilateral pleural effusion and usually manifests with bilateral interstitial lung disease, hilar lymphadenopathy, and non-necrotizing granulomas.^3,4

M tuberculosis and other granulomatous infections may also feign breast cancer.^5-13 Breast TB, which is highly uncommon in the developed world, often demonstrates imaging similar to that which was seen in this case. Breast TB may appear nodular with ill-defined contours. Masses are sometimes attached to the chest wall and usually lack microcalcifications on mammography; they are also typically hypoechoic and heterogenous on ultrasound, often showing posterior enhancement.^5,7,8 Like other breast infections, tuberculosis may show cutaneous sinus tract formation, which is seen in about one-third of patients.^6,7 Alternatively, it may manifest as a diffuse mastitis with skin thickening and axillary lymphadenopathy.⁸

Primary breast TB without chest disease comprises up to 86% of mammary tuberculosis.^6,7 Infection may occur via contamination of the skin or nipple.^5-7 Lactation, pregnancy, and other causes of immunosuppression (especially human immunodeficiency virus) have been associated with an increased risk of breast infection.^6-8 This patient was at risk for immunosuppression from longstanding diabetes.¹⁴

Many patients from TB-endemic areas have received the bacille Calmette-Guerin (BCG) vaccine and may exhibit equivocal or false-positive PPD results. Because interferon-gamma release assay TB blood tests (eg, QuantiFERON-TB Gold or T-SPOT.TB) are not affected by BCG, they are not associated with false-positive repeat testing results.¹⁵

Biopsy is necessary to rule out malignancy and diagnose breast TB

A pleural fluid to serum protein ratio >0.5 is consistent with infection, but also with sarcoidosis or malignancy.^3,16 Elevated pleural fluid adenosine deaminase (>40 U/L) is sensitive, albeit nonspecific, for the presence of TB microorganisms. If a lymphocyte-dominant exudate is also present, however, its reliability greatly increases.^16,17 Increased pleural fluid interferon-gamma is also sensitive and specific for TB pleurisy.¹⁸ Culture, along with drug sensitivity testing, should be performed on all unexplained pleural effusions.

This case emphasizes the need for increased awareness of extrapulmonary TB by physicians in developed countries.

A biopsy is often required to diagnose breast TB and should be performed on all suspicious lesions to exclude malignancy.^5-7,9 AFB stains and cultures of aspirate fluids or tissue are often negative.^7,9 PCR or other nucleic acid amplification tests of sputum, body fluids, or biopsy material may be positive in culture-negative cases and can rapidly confirm M tuberculosis infection.^17,19 No testing modality offers 100% sensitivity or specificity; therefore, an additional confirmatory test is desirable.

Possible routes of transmission include activation of latent pulmonary tuberculosis and direct, lymphatic, or hematologic extension to the chest wall and breast.^5-7 In this patient, we believe that activation of a latent breast granuloma may have resulted in a secondary or “sympathetic” pleural effusion, possibly triggered by surgical manipulation. This is compatible with her negative pleural adenosine deaminase result, negative culture, absence of pulmonary parenchymal disease, and negative pleural biopsy. Although we conducted a PubMed search, reviewing material as far back as 1966, we were unable to find a previous case of apparent sympathetic effusion associated with breast TB.

Our patient was treated with daily oral isoniazid, rifabutin, pyrazinamide, and ethambutol for 2 months, followed by isoniazid and rifabutin for 4 months. She has been disease-free for over 10 years.

THE TAKEAWAY

We describe a rare case of breast TB mimicking carcinoma that was associated with unilateral pleural effusion in a woman who had emigrated from Afghanistan. Patients at particular risk for breast TB include immigrants from endemic regions—especially parous females,^6,7 those with a history of TB contacts, and those who are immunosuppressed.⁸ This case emphasizes the need for increased awareness of extrapulmonary TB by physicians in developed countries.

ACKNOWLEDGEMENTS
The authors thank Drs. Margie Scott, Harpreet Dhillon, Samir Vora, Todd Williams, Jeffrey Hawley, and Mr. Sergio Landeros. This report is dedicated to the memory of our friend and colleague in medicine, Dr. Jeanie Care Gillinta.

THE CASE

A 44-year-old woman with a 15-year history of type 2 diabetes sought care for a firm, non-tender mass in the medial lower quadrant of her right breast. She hadn’t experienced any skin changes or axillary lymphadenopathy. The patient had immigrated to California from Afghanistan 22 years earlier, at which time she was briefly married to an Afghan man suffering from a chronic cough.

Mammography revealed a 3.5 x 4 x 4 cm lesion at the chest wall, which was highly suspicious for carcinoma (FIGURES 1A AND 1B). Sonography showed a heterogenous hypoechoic and isoechoic mass with posterior acoustic enhancement (FIGURE 1C). An excisional biopsy was performed.

One week postoperatively, the patient presented to the emergency department for a worsening nonproductive cough that intensified when supine, and was associated with subscapular pleuritic pain. She denied fever or weight loss. Biopsy results were pending.

THE DIAGNOSIS

Chest x-rays revealed a large right pleural effusion that was presumed to be malignant (FIGURES 1D AND 1E). Thoracentesis yielded 1.5 liters of tea-colored exudate containing 2800 nucleated cells/mL—63% lymphocytes and 37% neutrophils—and a pleural fluid to serum protein ratio >0.5. Adenosine deaminase was <1 U/L. Fluid Gram stain, acid-fast bacillus (AFB) fluorescent antibody testing, AFB cultures, and cytology were negative. Computed tomography (CT) subsequently demonstrated recurrent effusion without hilar or mediastinal lymphadenopathy or pleural enhancement (FIGURE 1F).

Histologically, the breast mass showed caseating granulomatous inflammation (FIGURES 1G AND 1H). An AFB stain was negative. Polymerase chain reaction (PCR) performed on DNA extracted from the formalin-fixed, paraffin-embedded biopsy material was positive for Mycobacterium tuberculosis.¹ A CT-guided pleural biopsy showed only normal tissue. A follow-up tuberculin skin test (purified protein derivative [PPD]) yielded a 10-mm indurated reaction.

DISCUSSION

Granulomatous lesions, such as foreign body granuloma, idiopathic granulomatous mastitis (IGM), and sarcoidosis can mimic breast carcinoma.^2,3 IGM is associated with elevated prolactin (eg, pregnancy or oral contraceptive use) and is usually subareolar.² Infection, however, is also commonly subareolar. Sarcoidosis rarely exhibits unilateral pleural effusion and usually manifests with bilateral interstitial lung disease, hilar lymphadenopathy, and non-necrotizing granulomas.^3,4

M tuberculosis and other granulomatous infections may also feign breast cancer.^5-13 Breast TB, which is highly uncommon in the developed world, often demonstrates imaging similar to that which was seen in this case. Breast TB may appear nodular with ill-defined contours. Masses are sometimes attached to the chest wall and usually lack microcalcifications on mammography; they are also typically hypoechoic and heterogenous on ultrasound, often showing posterior enhancement.^5,7,8 Like other breast infections, tuberculosis may show cutaneous sinus tract formation, which is seen in about one-third of patients.^6,7 Alternatively, it may manifest as a diffuse mastitis with skin thickening and axillary lymphadenopathy.⁸

Primary breast TB without chest disease comprises up to 86% of mammary tuberculosis.^6,7 Infection may occur via contamination of the skin or nipple.^5-7 Lactation, pregnancy, and other causes of immunosuppression (especially human immunodeficiency virus) have been associated with an increased risk of breast infection.^6-8 This patient was at risk for immunosuppression from longstanding diabetes.¹⁴

Many patients from TB-endemic areas have received the bacille Calmette-Guerin (BCG) vaccine and may exhibit equivocal or false-positive PPD results. Because interferon-gamma release assay TB blood tests (eg, QuantiFERON-TB Gold or T-SPOT.TB) are not affected by BCG, they are not associated with false-positive repeat testing results.¹⁵

Biopsy is necessary to rule out malignancy and diagnose breast TB

A pleural fluid to serum protein ratio >0.5 is consistent with infection, but also with sarcoidosis or malignancy.^3,16 Elevated pleural fluid adenosine deaminase (>40 U/L) is sensitive, albeit nonspecific, for the presence of TB microorganisms. If a lymphocyte-dominant exudate is also present, however, its reliability greatly increases.^16,17 Increased pleural fluid interferon-gamma is also sensitive and specific for TB pleurisy.¹⁸ Culture, along with drug sensitivity testing, should be performed on all unexplained pleural effusions.

This case emphasizes the need for increased awareness of extrapulmonary TB by physicians in developed countries.

A biopsy is often required to diagnose breast TB and should be performed on all suspicious lesions to exclude malignancy.^5-7,9 AFB stains and cultures of aspirate fluids or tissue are often negative.^7,9 PCR or other nucleic acid amplification tests of sputum, body fluids, or biopsy material may be positive in culture-negative cases and can rapidly confirm M tuberculosis infection.^17,19 No testing modality offers 100% sensitivity or specificity; therefore, an additional confirmatory test is desirable.

Possible routes of transmission include activation of latent pulmonary tuberculosis and direct, lymphatic, or hematologic extension to the chest wall and breast.^5-7 In this patient, we believe that activation of a latent breast granuloma may have resulted in a secondary or “sympathetic” pleural effusion, possibly triggered by surgical manipulation. This is compatible with her negative pleural adenosine deaminase result, negative culture, absence of pulmonary parenchymal disease, and negative pleural biopsy. Although we conducted a PubMed search, reviewing material as far back as 1966, we were unable to find a previous case of apparent sympathetic effusion associated with breast TB.

Our patient was treated with daily oral isoniazid, rifabutin, pyrazinamide, and ethambutol for 2 months, followed by isoniazid and rifabutin for 4 months. She has been disease-free for over 10 years.

THE TAKEAWAY

We describe a rare case of breast TB mimicking carcinoma that was associated with unilateral pleural effusion in a woman who had emigrated from Afghanistan. Patients at particular risk for breast TB include immigrants from endemic regions—especially parous females,^6,7 those with a history of TB contacts, and those who are immunosuppressed.⁸ This case emphasizes the need for increased awareness of extrapulmonary TB by physicians in developed countries.

ACKNOWLEDGEMENTS
The authors thank Drs. Margie Scott, Harpreet Dhillon, Samir Vora, Todd Williams, Jeffrey Hawley, and Mr. Sergio Landeros. This report is dedicated to the memory of our friend and colleague in medicine, Dr. Jeanie Care Gillinta.

Castleman disease or angiofollicular lymph node hyperplasia is an uncommon cause of an incidental abdominal mass found on imaging. The etiology of Castleman disease is relatively unknown, however, it is thought to be primarily associated with an oversecretion of interleukin-6. The oversecretion of this pro-inflammatory cytokine leads to lymph node hyperplasia. Castleman disease can be classified into 2 categories: unicentric or multicentric. Most cases of unicentric Castleman disease are asymptomatic and are found on routine imaging. It is found predominately in middle-aged persons of equal sex and is managed primarily by surgical resection. We present here a case of a peripancreatic mass diagnosed by surgical excision as Castleman disease, hyaline vascular type.

Click on the PDF icon at the top of this introduction to read the full article.

Castleman disease or angiofollicular lymph node hyperplasia is an uncommon cause of an incidental abdominal mass found on imaging. The etiology of Castleman disease is relatively unknown, however, it is thought to be primarily associated with an oversecretion of interleukin-6. The oversecretion of this pro-inflammatory cytokine leads to lymph node hyperplasia. Castleman disease can be classified into 2 categories: unicentric or multicentric. Most cases of unicentric Castleman disease are asymptomatic and are found on routine imaging. It is found predominately in middle-aged persons of equal sex and is managed primarily by surgical resection. We present here a case of a peripancreatic mass diagnosed by surgical excision as Castleman disease, hyaline vascular type.

Click on the PDF icon at the top of this introduction to read the full article.

Castleman disease or angiofollicular lymph node hyperplasia is an uncommon cause of an incidental abdominal mass found on imaging. The etiology of Castleman disease is relatively unknown, however, it is thought to be primarily associated with an oversecretion of interleukin-6. The oversecretion of this pro-inflammatory cytokine leads to lymph node hyperplasia. Castleman disease can be classified into 2 categories: unicentric or multicentric. Most cases of unicentric Castleman disease are asymptomatic and are found on routine imaging. It is found predominately in middle-aged persons of equal sex and is managed primarily by surgical resection. We present here a case of a peripancreatic mass diagnosed by surgical excision as Castleman disease, hyaline vascular type.

Click on the PDF icon at the top of this introduction to read the full article.

Paraneoplastic Isaacs syndrome is a rare disorder with distinct clinical and electromyographic characteristics. It is a consequence of neoplastic process that is not directly caused by the tumor itself, but usually mediated by immune response primarily against the tumor and neural tissues are damaged owing to bystander effect. Paraneoplastic neurologic disorders may precede cancer diagnosis. Here we report the case of 75-year-old woman who presented with numbness, tingling sensation, and weakness of lower extremities, and was diagnosed with Isaacs syndrome and subsequently small-cell lung cancer. Plasmapheresis and treatment of small-cell lung cancer produced signficant symptoms improvement. We also conduct a complete review of the published case reports and case series of Isaacs syndrome of paraneoplastic etiology, which usually has good response to carbamazepine and to specfic treatment of underlying neoplasm. 

Click on the PDF icon at the top of this introduction to read the full article.

Paraneoplastic Isaacs syndrome is a rare disorder with distinct clinical and electromyographic characteristics. It is a consequence of neoplastic process that is not directly caused by the tumor itself, but usually mediated by immune response primarily against the tumor and neural tissues are damaged owing to bystander effect. Paraneoplastic neurologic disorders may precede cancer diagnosis. Here we report the case of 75-year-old woman who presented with numbness, tingling sensation, and weakness of lower extremities, and was diagnosed with Isaacs syndrome and subsequently small-cell lung cancer. Plasmapheresis and treatment of small-cell lung cancer produced signficant symptoms improvement. We also conduct a complete review of the published case reports and case series of Isaacs syndrome of paraneoplastic etiology, which usually has good response to carbamazepine and to specfic treatment of underlying neoplasm. 

Click on the PDF icon at the top of this introduction to read the full article.

Paraneoplastic Isaacs syndrome is a rare disorder with distinct clinical and electromyographic characteristics. It is a consequence of neoplastic process that is not directly caused by the tumor itself, but usually mediated by immune response primarily against the tumor and neural tissues are damaged owing to bystander effect. Paraneoplastic neurologic disorders may precede cancer diagnosis. Here we report the case of 75-year-old woman who presented with numbness, tingling sensation, and weakness of lower extremities, and was diagnosed with Isaacs syndrome and subsequently small-cell lung cancer. Plasmapheresis and treatment of small-cell lung cancer produced signficant symptoms improvement. We also conduct a complete review of the published case reports and case series of Isaacs syndrome of paraneoplastic etiology, which usually has good response to carbamazepine and to specfic treatment of underlying neoplasm. 

Click on the PDF icon at the top of this introduction to read the full article.

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.

Approximately 600 cases of operating room (OR) fires are reported annually.¹ The incidence of OR fires in the United States equals that of wrong-site surgeries, and 20% of cases have associated morbidity.^1,2 The estimated mortality rate is 1 to 2 cases per year.^3-5 The most commonly involved anatomical regions are the airway (33%) and the face (28%).⁴ Most surgical fires are reported in anesthetized patients with open oxygen delivery systems during head, neck, and upper chest surgeries; electrosurgical instruments are the ignition source in 90% of these cases.⁶ Despite extensive fire safety education and training, complete elimination of OR fires still has not been achieved.

Each fire requires an ignition source, a fuel source, and an oxidizer.⁷ In the OR, the 2 most common oxidizers are oxygen and nitrous oxide. Head and neck surgeries have a high concentration of these gases near the working field and therefore a higher risk and incidence of fires. Furthermore, surgical drapes and equipment (eg, closed or semi-closed breathing systems, masks) may potentiate this risk by reducing ventilation in areas where gases can accumulate and ignite. Ignition sources provide the energy that starts fires; common sources are electrocautery, lasers, fiber-optic light cords, drills/burrs, and defibrillator paddles. Fires are propagated by fuel sources, which encompass any flammable material, including tracheal tubes, sponges, alcohol-based solutions, hair, gastrointestinal tract gases, gloves, and packaging materials.⁸ Of note, alcohol-based skin-preparation agents emit flammable vapors that can ignite.^9-14 Before draping or exposure to an ignition source, chlorhexidine gluconate-based preparations must be allowed to dry for at least 3 minutes after application to hairless skin and up to 1 hour after application to hair.¹⁵ Inadequate drying poses a risk of fire.¹⁰We present the case of an OR fire ignited by electrocautery near freshly applied bone cement. No patient information is disclosed in this report.

Case Report

Our patient was evaluated in clinic and scheduled for total knee arthroplasty (TKA). All preoperative safety checklists and time-out procedures were followed and documented at the start of surgery. The TKA was performed with a standard medial patellar arthrotomy. Tourniquet control was used after Esmarch exsanguination. The surgery proceeded uneventfully until just after the bone cement was applied to the tibial surface. The surgeon was using a Bovie to resect residual lateral meniscus tissue when a fire instantaneously erupted within the joint space. Fortunately, the surgeon quickly suffocated the fire with a dry towel. The ignited bone cement was removed, and the patient was examined. There was no injury to surrounding tissue or joint space. Surgery was resumed with application of new bone cement to the tibial surface. The artificial joint was then successfully implanted and the case completed without further incident. The patient was discharged from the hospital and followed up as an outpatient without any postoperative complications.

Discussion

Bone cement, which is commonly used in artificial joint anchoring, craniofacial reconstruction, and vertebroplasty, has liquid and powder components. The liquid monomer methyl methacrylate (MMA) is colorless and flammable and has a distinct odor.¹⁶ Exposure to heat or light can prematurely polymerize MMA, requiring the addition of hydroquinone to inhibit the reaction.¹⁶ The powder polymethylmethacrylate affords excellent structural support, radiopacity, and facility of use.¹⁷ Dibenzoyl peroxide and N,N-dimethyl-p-toluidine are added to the powder to facilitate the polymerization reaction at room temperature (ie, cold curing of cement). Premature application of unpolymerized cement increases the risk of fire from the volatile liquid component.

In the OR, bone cement is prepared by mixing together its powder and liquid components.¹⁸ The reaction is exothermic polymerization. The liquid is highly volatile and flammable in both liquid and vapor states.^16,19 The vapors are denser than air and can concentrate in poorly ventilated areas. The OR and the application site must be adequately ventilated to eliminate any pockets of vapor accumulation.¹⁶ A vacuum mixer can be used to minimize fume exposure, enhance cement strength, and reduce fire risk while combining the 2 components.

MMA’s flash point, the temperature at which the fumes could ignite in the presence of an ignition source, is 10.5ºC. The auto-ignition point, the temperature at which MMA spontaneously combusts, is 421ºC.²⁰ The OR is usually warmer than the flash point temperature, but the electrocautery tip can generate up to 1200ºC of heat.²¹ Therefore, bone cement is a potential fire hazard, and use of Bovies or other ignition sources in its vicinity must be avoided.

The Table lists the recommended times for preparing various bone cement products.^22,23Mix time is the time needed to combine the liquid and powder into a homogenous putty.

Approximately 600 cases of operating room (OR) fires are reported annually.¹ The incidence of OR fires in the United States equals that of wrong-site surgeries, and 20% of cases have associated morbidity.^1,2 The estimated mortality rate is 1 to 2 cases per year.^3-5 The most commonly involved anatomical regions are the airway (33%) and the face (28%).⁴ Most surgical fires are reported in anesthetized patients with open oxygen delivery systems during head, neck, and upper chest surgeries; electrosurgical instruments are the ignition source in 90% of these cases.⁶ Despite extensive fire safety education and training, complete elimination of OR fires still has not been achieved.

Each fire requires an ignition source, a fuel source, and an oxidizer.⁷ In the OR, the 2 most common oxidizers are oxygen and nitrous oxide. Head and neck surgeries have a high concentration of these gases near the working field and therefore a higher risk and incidence of fires. Furthermore, surgical drapes and equipment (eg, closed or semi-closed breathing systems, masks) may potentiate this risk by reducing ventilation in areas where gases can accumulate and ignite. Ignition sources provide the energy that starts fires; common sources are electrocautery, lasers, fiber-optic light cords, drills/burrs, and defibrillator paddles. Fires are propagated by fuel sources, which encompass any flammable material, including tracheal tubes, sponges, alcohol-based solutions, hair, gastrointestinal tract gases, gloves, and packaging materials.⁸ Of note, alcohol-based skin-preparation agents emit flammable vapors that can ignite.^9-14 Before draping or exposure to an ignition source, chlorhexidine gluconate-based preparations must be allowed to dry for at least 3 minutes after application to hairless skin and up to 1 hour after application to hair.¹⁵ Inadequate drying poses a risk of fire.¹⁰We present the case of an OR fire ignited by electrocautery near freshly applied bone cement. No patient information is disclosed in this report.

Case Report

Our patient was evaluated in clinic and scheduled for total knee arthroplasty (TKA). All preoperative safety checklists and time-out procedures were followed and documented at the start of surgery. The TKA was performed with a standard medial patellar arthrotomy. Tourniquet control was used after Esmarch exsanguination. The surgery proceeded uneventfully until just after the bone cement was applied to the tibial surface. The surgeon was using a Bovie to resect residual lateral meniscus tissue when a fire instantaneously erupted within the joint space. Fortunately, the surgeon quickly suffocated the fire with a dry towel. The ignited bone cement was removed, and the patient was examined. There was no injury to surrounding tissue or joint space. Surgery was resumed with application of new bone cement to the tibial surface. The artificial joint was then successfully implanted and the case completed without further incident. The patient was discharged from the hospital and followed up as an outpatient without any postoperative complications.

Discussion

Bone cement, which is commonly used in artificial joint anchoring, craniofacial reconstruction, and vertebroplasty, has liquid and powder components. The liquid monomer methyl methacrylate (MMA) is colorless and flammable and has a distinct odor.¹⁶ Exposure to heat or light can prematurely polymerize MMA, requiring the addition of hydroquinone to inhibit the reaction.¹⁶ The powder polymethylmethacrylate affords excellent structural support, radiopacity, and facility of use.¹⁷ Dibenzoyl peroxide and N,N-dimethyl-p-toluidine are added to the powder to facilitate the polymerization reaction at room temperature (ie, cold curing of cement). Premature application of unpolymerized cement increases the risk of fire from the volatile liquid component.

In the OR, bone cement is prepared by mixing together its powder and liquid components.¹⁸ The reaction is exothermic polymerization. The liquid is highly volatile and flammable in both liquid and vapor states.^16,19 The vapors are denser than air and can concentrate in poorly ventilated areas. The OR and the application site must be adequately ventilated to eliminate any pockets of vapor accumulation.¹⁶ A vacuum mixer can be used to minimize fume exposure, enhance cement strength, and reduce fire risk while combining the 2 components.

MMA’s flash point, the temperature at which the fumes could ignite in the presence of an ignition source, is 10.5ºC. The auto-ignition point, the temperature at which MMA spontaneously combusts, is 421ºC.²⁰ The OR is usually warmer than the flash point temperature, but the electrocautery tip can generate up to 1200ºC of heat.²¹ Therefore, bone cement is a potential fire hazard, and use of Bovies or other ignition sources in its vicinity must be avoided.

The Table lists the recommended times for preparing various bone cement products.^22,23Mix time is the time needed to combine the liquid and powder into a homogenous putty.

Approximately 600 cases of operating room (OR) fires are reported annually.¹ The incidence of OR fires in the United States equals that of wrong-site surgeries, and 20% of cases have associated morbidity.^1,2 The estimated mortality rate is 1 to 2 cases per year.^3-5 The most commonly involved anatomical regions are the airway (33%) and the face (28%).⁴ Most surgical fires are reported in anesthetized patients with open oxygen delivery systems during head, neck, and upper chest surgeries; electrosurgical instruments are the ignition source in 90% of these cases.⁶ Despite extensive fire safety education and training, complete elimination of OR fires still has not been achieved.

Each fire requires an ignition source, a fuel source, and an oxidizer.⁷ In the OR, the 2 most common oxidizers are oxygen and nitrous oxide. Head and neck surgeries have a high concentration of these gases near the working field and therefore a higher risk and incidence of fires. Furthermore, surgical drapes and equipment (eg, closed or semi-closed breathing systems, masks) may potentiate this risk by reducing ventilation in areas where gases can accumulate and ignite. Ignition sources provide the energy that starts fires; common sources are electrocautery, lasers, fiber-optic light cords, drills/burrs, and defibrillator paddles. Fires are propagated by fuel sources, which encompass any flammable material, including tracheal tubes, sponges, alcohol-based solutions, hair, gastrointestinal tract gases, gloves, and packaging materials.⁸ Of note, alcohol-based skin-preparation agents emit flammable vapors that can ignite.^9-14 Before draping or exposure to an ignition source, chlorhexidine gluconate-based preparations must be allowed to dry for at least 3 minutes after application to hairless skin and up to 1 hour after application to hair.¹⁵ Inadequate drying poses a risk of fire.¹⁰We present the case of an OR fire ignited by electrocautery near freshly applied bone cement. No patient information is disclosed in this report.

Case Report

Our patient was evaluated in clinic and scheduled for total knee arthroplasty (TKA). All preoperative safety checklists and time-out procedures were followed and documented at the start of surgery. The TKA was performed with a standard medial patellar arthrotomy. Tourniquet control was used after Esmarch exsanguination. The surgery proceeded uneventfully until just after the bone cement was applied to the tibial surface. The surgeon was using a Bovie to resect residual lateral meniscus tissue when a fire instantaneously erupted within the joint space. Fortunately, the surgeon quickly suffocated the fire with a dry towel. The ignited bone cement was removed, and the patient was examined. There was no injury to surrounding tissue or joint space. Surgery was resumed with application of new bone cement to the tibial surface. The artificial joint was then successfully implanted and the case completed without further incident. The patient was discharged from the hospital and followed up as an outpatient without any postoperative complications.

Discussion

Bone cement, which is commonly used in artificial joint anchoring, craniofacial reconstruction, and vertebroplasty, has liquid and powder components. The liquid monomer methyl methacrylate (MMA) is colorless and flammable and has a distinct odor.¹⁶ Exposure to heat or light can prematurely polymerize MMA, requiring the addition of hydroquinone to inhibit the reaction.¹⁶ The powder polymethylmethacrylate affords excellent structural support, radiopacity, and facility of use.¹⁷ Dibenzoyl peroxide and N,N-dimethyl-p-toluidine are added to the powder to facilitate the polymerization reaction at room temperature (ie, cold curing of cement). Premature application of unpolymerized cement increases the risk of fire from the volatile liquid component.

In the OR, bone cement is prepared by mixing together its powder and liquid components.¹⁸ The reaction is exothermic polymerization. The liquid is highly volatile and flammable in both liquid and vapor states.^16,19 The vapors are denser than air and can concentrate in poorly ventilated areas. The OR and the application site must be adequately ventilated to eliminate any pockets of vapor accumulation.¹⁶ A vacuum mixer can be used to minimize fume exposure, enhance cement strength, and reduce fire risk while combining the 2 components.

MMA’s flash point, the temperature at which the fumes could ignite in the presence of an ignition source, is 10.5ºC. The auto-ignition point, the temperature at which MMA spontaneously combusts, is 421ºC.²⁰ The OR is usually warmer than the flash point temperature, but the electrocautery tip can generate up to 1200ºC of heat.²¹ Therefore, bone cement is a potential fire hazard, and use of Bovies or other ignition sources in its vicinity must be avoided.

The Table lists the recommended times for preparing various bone cement products.^22,23Mix time is the time needed to combine the liquid and powder into a homogenous putty.

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

Malignant melanoma has continually shown a pattern of increased incidence and mortality over the last 50 years, especially in fair-skinned individuals. In fact, malignant melanoma has the highest mortality rate of all skin cancers in white individuals. Currently, wide local surgical excision is the mainstay of treatment of primary cutaneous melanomas.¹ The margins vary in size according to the Breslow thickness (or depth) of the involved tumor. As such, advancements in melanoma treatment continue to be studied. We present the case of a patient with invasive melanoma that was cleared with topical imiquimod.

Case Report

A 71-year-old man presented with biopsy-proven malignant melanoma on the right posterior scalp that was diagnosed a few weeks prior. The melanoma was invasive with a depth of 0.73 mm. The patient also had an approximately 8-cm, irregular, patchy area of hyperpigmentation involving almost the entire crown of the head (Figure 1A). The biopsy site used for melanoma diagnosis was on the right posterior aspect of the hyperpigmented area where a symptomatic pigmented papule was located. To determine if the rest of this macule represented an extension of the proven malignancy, surveillance biopsies were taken at the 12 o'clock (anterior aspect), 3 o'clock, 6 o'clock, and 9 o'clock positions on the head. All of the biopsies came back as lentigo simplex, which presented a clinical problem in that the boundaries of the invasive melanoma merged with the lentigo simplex and were not clinically apparent. Because an exact boundary could not be visualized, the entire area was treated with imiquimod cream 5% once nightly at bedtime for 4 weeks prior to excision of the original biopsy site. There was a notable decrease in hyperpigmentation in the treated area after 4 weeks of therapy (Figure 1B). The original biopsy site was then excised with a 0.6-cm margin and a complex linear repair was performed. Histologic examination of the excised specimen showed no residual melanoma.

Comment

Although surgical excision is the recommended treatment of cutaneous melanoma,¹ in some cases the defect following an excision can be quite large or even disfiguring. To minimize the size of the excision site, other treatment modalities should be studied. Imiquimod is an immunomodulating agent that exerts antitumor and antiviral effects. The US Food and Drug Administration has approved imiquimod for treatment of genital warts, actinic keratoses, and superficial basal cell carcinoma.² The most common side effects of topical imiquimod involve application-site reactions such as erythema, swelling, and crusting of the treated area. Ulceration of the skin also is possible. A small percentage of individuals have experienced systemic flulike symptoms after using topical imiquimod. Topical imiquimod has been used off label to treat noninvasive forms of melanoma. The topical therapy has been reported to clear melanoma in situ and lentigo maligna.^2,3 In addition, imiquimod has been used as a palliative therapy for cutaneous metastatic melanoma.^4,5 In another case of a primary melanoma that responded to topical imiquimod, clinical and histological clearance of a recurrent oral mucosa melanoma was obtained.⁶

Moon and Spencer⁷ reported a case of an invasive melanoma that was cleared with topical imiquimod. A 93-year-old woman presented with a central 2.75-mm thick invasive melanoma surrounded by a large area of melanoma in situ involving the left cheek and eyelid. The excised tissue was stained for CD31 and D2-40 to rule out intravascular and intralymphatic spread (Figure 2A). The standard-of-care treatment for this case would involve surgical excision with 2-cm margins and a sentinel lymph node biopsy, but given the morbidity involved with the surgery, an alternative treatment plan was made with the patient. The patient completed 5 weeks of topical imiquimod therapy and then underwent wide local excision with a 1-cm margin. Extensive histological examination of the excised specimen showed no residual melanoma; in fact, there was a near absence of junctional melanocytes that would normally have been seen. The specimen underwent immunoperoxidase staining for Melan-A (Figure 2B). The patient was followed for 14 months with no evidence of recurrence.⁷

Conclusion

We describe a patient who achieved complete histologic clearance of invasive melanoma following treatment with topical imiquimod. Four weeks of topical therapy completely cleared an invasive melanoma that was 0.73-mm thick. Follow-up was recommended for the patient because long-term outcomes of this therapy are unknown. More studies demonstrating reliability and reproducibility are needed to evaluate the role of topical imiquimod in melanoma treatment; however, our case shows the potential of this topical modality.

Malignant melanoma has continually shown a pattern of increased incidence and mortality over the last 50 years, especially in fair-skinned individuals. In fact, malignant melanoma has the highest mortality rate of all skin cancers in white individuals. Currently, wide local surgical excision is the mainstay of treatment of primary cutaneous melanomas.¹ The margins vary in size according to the Breslow thickness (or depth) of the involved tumor. As such, advancements in melanoma treatment continue to be studied. We present the case of a patient with invasive melanoma that was cleared with topical imiquimod.

Case Report

A 71-year-old man presented with biopsy-proven malignant melanoma on the right posterior scalp that was diagnosed a few weeks prior. The melanoma was invasive with a depth of 0.73 mm. The patient also had an approximately 8-cm, irregular, patchy area of hyperpigmentation involving almost the entire crown of the head (Figure 1A). The biopsy site used for melanoma diagnosis was on the right posterior aspect of the hyperpigmented area where a symptomatic pigmented papule was located. To determine if the rest of this macule represented an extension of the proven malignancy, surveillance biopsies were taken at the 12 o'clock (anterior aspect), 3 o'clock, 6 o'clock, and 9 o'clock positions on the head. All of the biopsies came back as lentigo simplex, which presented a clinical problem in that the boundaries of the invasive melanoma merged with the lentigo simplex and were not clinically apparent. Because an exact boundary could not be visualized, the entire area was treated with imiquimod cream 5% once nightly at bedtime for 4 weeks prior to excision of the original biopsy site. There was a notable decrease in hyperpigmentation in the treated area after 4 weeks of therapy (Figure 1B). The original biopsy site was then excised with a 0.6-cm margin and a complex linear repair was performed. Histologic examination of the excised specimen showed no residual melanoma.

Comment

Although surgical excision is the recommended treatment of cutaneous melanoma,¹ in some cases the defect following an excision can be quite large or even disfiguring. To minimize the size of the excision site, other treatment modalities should be studied. Imiquimod is an immunomodulating agent that exerts antitumor and antiviral effects. The US Food and Drug Administration has approved imiquimod for treatment of genital warts, actinic keratoses, and superficial basal cell carcinoma.² The most common side effects of topical imiquimod involve application-site reactions such as erythema, swelling, and crusting of the treated area. Ulceration of the skin also is possible. A small percentage of individuals have experienced systemic flulike symptoms after using topical imiquimod. Topical imiquimod has been used off label to treat noninvasive forms of melanoma. The topical therapy has been reported to clear melanoma in situ and lentigo maligna.^2,3 In addition, imiquimod has been used as a palliative therapy for cutaneous metastatic melanoma.^4,5 In another case of a primary melanoma that responded to topical imiquimod, clinical and histological clearance of a recurrent oral mucosa melanoma was obtained.⁶

Moon and Spencer⁷ reported a case of an invasive melanoma that was cleared with topical imiquimod. A 93-year-old woman presented with a central 2.75-mm thick invasive melanoma surrounded by a large area of melanoma in situ involving the left cheek and eyelid. The excised tissue was stained for CD31 and D2-40 to rule out intravascular and intralymphatic spread (Figure 2A). The standard-of-care treatment for this case would involve surgical excision with 2-cm margins and a sentinel lymph node biopsy, but given the morbidity involved with the surgery, an alternative treatment plan was made with the patient. The patient completed 5 weeks of topical imiquimod therapy and then underwent wide local excision with a 1-cm margin. Extensive histological examination of the excised specimen showed no residual melanoma; in fact, there was a near absence of junctional melanocytes that would normally have been seen. The specimen underwent immunoperoxidase staining for Melan-A (Figure 2B). The patient was followed for 14 months with no evidence of recurrence.⁷

Conclusion

We describe a patient who achieved complete histologic clearance of invasive melanoma following treatment with topical imiquimod. Four weeks of topical therapy completely cleared an invasive melanoma that was 0.73-mm thick. Follow-up was recommended for the patient because long-term outcomes of this therapy are unknown. More studies demonstrating reliability and reproducibility are needed to evaluate the role of topical imiquimod in melanoma treatment; however, our case shows the potential of this topical modality.

Malignant melanoma has continually shown a pattern of increased incidence and mortality over the last 50 years, especially in fair-skinned individuals. In fact, malignant melanoma has the highest mortality rate of all skin cancers in white individuals. Currently, wide local surgical excision is the mainstay of treatment of primary cutaneous melanomas.¹ The margins vary in size according to the Breslow thickness (or depth) of the involved tumor. As such, advancements in melanoma treatment continue to be studied. We present the case of a patient with invasive melanoma that was cleared with topical imiquimod.

Case Report

A 71-year-old man presented with biopsy-proven malignant melanoma on the right posterior scalp that was diagnosed a few weeks prior. The melanoma was invasive with a depth of 0.73 mm. The patient also had an approximately 8-cm, irregular, patchy area of hyperpigmentation involving almost the entire crown of the head (Figure 1A). The biopsy site used for melanoma diagnosis was on the right posterior aspect of the hyperpigmented area where a symptomatic pigmented papule was located. To determine if the rest of this macule represented an extension of the proven malignancy, surveillance biopsies were taken at the 12 o'clock (anterior aspect), 3 o'clock, 6 o'clock, and 9 o'clock positions on the head. All of the biopsies came back as lentigo simplex, which presented a clinical problem in that the boundaries of the invasive melanoma merged with the lentigo simplex and were not clinically apparent. Because an exact boundary could not be visualized, the entire area was treated with imiquimod cream 5% once nightly at bedtime for 4 weeks prior to excision of the original biopsy site. There was a notable decrease in hyperpigmentation in the treated area after 4 weeks of therapy (Figure 1B). The original biopsy site was then excised with a 0.6-cm margin and a complex linear repair was performed. Histologic examination of the excised specimen showed no residual melanoma.

Comment

Although surgical excision is the recommended treatment of cutaneous melanoma,¹ in some cases the defect following an excision can be quite large or even disfiguring. To minimize the size of the excision site, other treatment modalities should be studied. Imiquimod is an immunomodulating agent that exerts antitumor and antiviral effects. The US Food and Drug Administration has approved imiquimod for treatment of genital warts, actinic keratoses, and superficial basal cell carcinoma.² The most common side effects of topical imiquimod involve application-site reactions such as erythema, swelling, and crusting of the treated area. Ulceration of the skin also is possible. A small percentage of individuals have experienced systemic flulike symptoms after using topical imiquimod. Topical imiquimod has been used off label to treat noninvasive forms of melanoma. The topical therapy has been reported to clear melanoma in situ and lentigo maligna.^2,3 In addition, imiquimod has been used as a palliative therapy for cutaneous metastatic melanoma.^4,5 In another case of a primary melanoma that responded to topical imiquimod, clinical and histological clearance of a recurrent oral mucosa melanoma was obtained.⁶

Moon and Spencer⁷ reported a case of an invasive melanoma that was cleared with topical imiquimod. A 93-year-old woman presented with a central 2.75-mm thick invasive melanoma surrounded by a large area of melanoma in situ involving the left cheek and eyelid. The excised tissue was stained for CD31 and D2-40 to rule out intravascular and intralymphatic spread (Figure 2A). The standard-of-care treatment for this case would involve surgical excision with 2-cm margins and a sentinel lymph node biopsy, but given the morbidity involved with the surgery, an alternative treatment plan was made with the patient. The patient completed 5 weeks of topical imiquimod therapy and then underwent wide local excision with a 1-cm margin. Extensive histological examination of the excised specimen showed no residual melanoma; in fact, there was a near absence of junctional melanocytes that would normally have been seen. The specimen underwent immunoperoxidase staining for Melan-A (Figure 2B). The patient was followed for 14 months with no evidence of recurrence.⁷

Conclusion

We describe a patient who achieved complete histologic clearance of invasive melanoma following treatment with topical imiquimod. Four weeks of topical therapy completely cleared an invasive melanoma that was 0.73-mm thick. Follow-up was recommended for the patient because long-term outcomes of this therapy are unknown. More studies demonstrating reliability and reproducibility are needed to evaluate the role of topical imiquimod in melanoma treatment; however, our case shows the potential of this topical modality.

Case Report

A 78-year-old man presented for evaluation of 4 painful keratotic nodules that had appeared on the dorsal aspect of the right thumb, the first web space of the right hand, and the first web space of the left hand. The nodules developed in pericicatricial skin following Mohs micrographic surgery to the affected areas for treatment of invasive squamous cell carcinomas (SCCs) 2 months prior. The patient had worked in lawn maintenance for decades and continued to garden on an avocational basis. He denied exposure to angling or aquariums.

On physical examination the lesions appeared as firm, dusky-violaceous, crusted nodules (Figure 1). Brown patches of hyperpigmentation or characteristic cornlike elevations of the palm were not present to implicate arsenic exposure. Extensive sun damage to the face, neck, forearms, and dorsal aspect of the hands was noted. Epitrochlear lymphadenopathy or lymphangitic streaking were not appreciated. Routine hematologic parameters including leukocyte count were normal, except for chronic thrombocytopenia. Computerized tomography of the abdomen demonstrated no hepatosplenomegaly or enlarged lymph nodes. Hematoxylin and eosin staining of biopsy specimens from the right thumb showed irregular squamous epithelial hyperplasia with an impetiginized scale crust and pustular tissue reaction, including suppurative abscess formation in the dermis (Figure 2). Initial acid-fast staining performed on the biopsy from the right thumb was negative for microorganisms. Given the concerning histologic features indicating infection, a tissue culture was performed. Subsequent growth on Lowenstein-Jensen culture medium confirmed infection with Mycobacterium avium complex (MAC). The patient was started on clarithromycin 500 mg twice daily in accordance with laboratory susceptibilities, and the cutaneous nodules improved. Unfortunately, the patient died 6 months later secondary to cardiac arrest.

Comment

The genus Mycobacterium comprises more than 130 described bacteria, including the precipitants of tuberculosis and leprosy. Mycobacterium avium complex--an umbrella term for M avium, Mycobacterium intracellulare, and other close relatives--is a member of the genus that maintains a low pathogenicity for healthy individuals.^1,2 Nonetheless, MAC accounts for more than 70% of cases of nontuberculous mycobacterial disease in the United States.³Mycobacterium avium complex typically acts as a respiratory pathogen, but infection may manifest with lymphadenitis, osteomyelitis, hepatosplenomegaly, or skin involvement. Disseminated MAC infection can occur in patients with defective immune systems, including those with conditions such as AIDS or hairy cell leukemia and those undergoing immunosuppressive therapy.^1,4 Although uncommon, cutaneous infection with MAC occurs via 3 possible mechanisms: (1) primary inoculation, (2) lymphogenous extension, or (3) hematologic dissemination.⁴ According to a PubMed search of articles indexed for MEDLINE using the terms primary cutaneous Mycobacterium avium complex and MAC skin infection, only 11 known cases of primary cutaneous MAC infection have been reported in the English-language literature,^4-14  the most recent being a report by Landriscina et al.¹¹

A Runyon group III bacillus, MAC is a slow-growing nonchromogen that is ubiquitous in nature.¹⁵ It has been isolated from soil, water, house dust, vegetables, eggs, and milk. According to Reed et al,³ occupational exposure to soil is an independent risk factor for MAC infection, with individuals reporting more than 6 years of cumulative participation in lawn and landscaping services, farming, or other occupations involving substantial exposure to dirt or dust most likely to be MAC-positive. Cutaneous MAC infection may be associated with water exposure, as Sugita et al² described one familial outbreak of cutaneous MAC infection linked to use of a circulating, constantly heated bathwater system. With respect to US geography, individuals living in rural areas of the South seem most prone to MAC infection.³

Primary cutaneous infection with MAC occurs after a breach in the skin surface, though this fact may not be elicited by history. Modes of entry include minor abrasions after falling,¹ small wounds,² traumatic inoculation,¹⁵ and intramuscular injection.¹⁶ Clinically, cutaneous lesions of MAC are protean. In the literature, clinical presentation is described as a polymorphous appearance with scaling plaques, verrucous nodules, crusted ulcers, inflammatory nodules, dermatitis, panniculitis, draining sinuses, ecthymatous lesions, sporotrichoid growth patterns, or rosacealike papulopustules.^1,15,17 Lesions may affect the arms and legs, trunk, buttocks, and face.¹⁸

The differential diagnosis of MAC infection includes lupus vulgaris, Mycobacterium marinum infection (also known as swimming pool granuloma), sporotrichosis, nocardiosis, sarcoidosis, neutrophilic dermatosis, pyoderma gangrenosum, and cutaneous blastomycosis. Given its rarity and variability, diagnosis of MAC infection requires a high index of suspicion. Cutaneous MAC infection should be considered if a nodule, plaque, or ulcer fails to respond to conventional treatment, especially in patients with a history of environmental exposure and possible injury to the skin.

We report a rare case of primary cutaneous MAC infection arising in SCC excision sites in a patient without known immune deficiency. This presentation may have occurred for several reasons. First, the surgical excision sites coupled with the substantial occupational and recreational exposure to soil experienced by our patient may have served as portals for infection. Although SCCs are common on the hands, Mohs micrographic surgery is not always performed for excision; in our patient's case, this approach allowed for maximum tissue conservation and preserved manual function given the number and location of the lesions. Second, despite an overtly intact immune system, our patient may have harbored an occult immune deficiency, predisposing him to dermatologic infection with a microorganism of low intrinsic virulence and recurrent malignant neoplasms. This presentation may have been the first clinical indication of subtle immune compromise. For example, inadequate proinflammatory cytokines may contribute to both mycobacterial and malignant disease. A potential risk of inhibition of tumor necrosis factor α is the unmasking of tuberculosis or lymphoma.^19,20 Likewise, IFN-γ is vital in suppressing mycobacteria and malignancy. Yonekura et al²¹ found that IFN-γ induces apoptosis in oral SCC lines. It follows that a paucity of IFN-γ could allow neoplastic growth. Normal function of IFN-γ prompts microbicidal activity in macrophages and stimulates granuloma formation, both of which combat mycobacterial infection.¹⁹ A final postulation is that a simmering cutaneous MAC infection precipitated neoplastic degeneration into SCC, much the same way that the human papillomavirus has been correlated in the carcinogenesis of cervical cancer. As an intracellular microbe, MAC could cause the genetic machinery of skin cells to go awry. Kullavanijaya et al¹⁸ described a patient with cutaneous MAC in association with cervical cancer.

Conclusion

This association of primary cutaneous MAC infection and cutaneous malignancy in a reportedly immunocompetent patient is rare. Cancer patients, as noted by Feld et al,²² are 3 times more likely to develop infections with mycobacteria, with SCC, lymphoma, and leukemia being most commonly indicated. A specific immune deficit in the IFN-γ receptor is known to confer a selective predisposition to mycobacterial infection.^23,24 Toyoda et al²⁵ outlined the case of a pediatric patient with IFN-γ receptor 2 deficiency who presented with disseminated MAC infection and later succumbed to multiple SCCs of the hands and face. The authors' assertion was that inherited disorders of IFN-γ-mediated immunity may be associated with SCCs.²⁵ Unfortunately, our patient died before more specific immunological testing could be conducted. This case highlights the remarkable singularity of primary cutaneous MAC infection in association with multiple SCCs with seemingly intact immune status and offers some intriguing hypotheses regarding its occurrence.

Case Report

A 78-year-old man presented for evaluation of 4 painful keratotic nodules that had appeared on the dorsal aspect of the right thumb, the first web space of the right hand, and the first web space of the left hand. The nodules developed in pericicatricial skin following Mohs micrographic surgery to the affected areas for treatment of invasive squamous cell carcinomas (SCCs) 2 months prior. The patient had worked in lawn maintenance for decades and continued to garden on an avocational basis. He denied exposure to angling or aquariums.

On physical examination the lesions appeared as firm, dusky-violaceous, crusted nodules (Figure 1). Brown patches of hyperpigmentation or characteristic cornlike elevations of the palm were not present to implicate arsenic exposure. Extensive sun damage to the face, neck, forearms, and dorsal aspect of the hands was noted. Epitrochlear lymphadenopathy or lymphangitic streaking were not appreciated. Routine hematologic parameters including leukocyte count were normal, except for chronic thrombocytopenia. Computerized tomography of the abdomen demonstrated no hepatosplenomegaly or enlarged lymph nodes. Hematoxylin and eosin staining of biopsy specimens from the right thumb showed irregular squamous epithelial hyperplasia with an impetiginized scale crust and pustular tissue reaction, including suppurative abscess formation in the dermis (Figure 2). Initial acid-fast staining performed on the biopsy from the right thumb was negative for microorganisms. Given the concerning histologic features indicating infection, a tissue culture was performed. Subsequent growth on Lowenstein-Jensen culture medium confirmed infection with Mycobacterium avium complex (MAC). The patient was started on clarithromycin 500 mg twice daily in accordance with laboratory susceptibilities, and the cutaneous nodules improved. Unfortunately, the patient died 6 months later secondary to cardiac arrest.

Comment

The genus Mycobacterium comprises more than 130 described bacteria, including the precipitants of tuberculosis and leprosy. Mycobacterium avium complex--an umbrella term for M avium, Mycobacterium intracellulare, and other close relatives--is a member of the genus that maintains a low pathogenicity for healthy individuals.^1,2 Nonetheless, MAC accounts for more than 70% of cases of nontuberculous mycobacterial disease in the United States.³Mycobacterium avium complex typically acts as a respiratory pathogen, but infection may manifest with lymphadenitis, osteomyelitis, hepatosplenomegaly, or skin involvement. Disseminated MAC infection can occur in patients with defective immune systems, including those with conditions such as AIDS or hairy cell leukemia and those undergoing immunosuppressive therapy.^1,4 Although uncommon, cutaneous infection with MAC occurs via 3 possible mechanisms: (1) primary inoculation, (2) lymphogenous extension, or (3) hematologic dissemination.⁴ According to a PubMed search of articles indexed for MEDLINE using the terms primary cutaneous Mycobacterium avium complex and MAC skin infection, only 11 known cases of primary cutaneous MAC infection have been reported in the English-language literature,^4-14  the most recent being a report by Landriscina et al.¹¹

A Runyon group III bacillus, MAC is a slow-growing nonchromogen that is ubiquitous in nature.¹⁵ It has been isolated from soil, water, house dust, vegetables, eggs, and milk. According to Reed et al,³ occupational exposure to soil is an independent risk factor for MAC infection, with individuals reporting more than 6 years of cumulative participation in lawn and landscaping services, farming, or other occupations involving substantial exposure to dirt or dust most likely to be MAC-positive. Cutaneous MAC infection may be associated with water exposure, as Sugita et al² described one familial outbreak of cutaneous MAC infection linked to use of a circulating, constantly heated bathwater system. With respect to US geography, individuals living in rural areas of the South seem most prone to MAC infection.³

Primary cutaneous infection with MAC occurs after a breach in the skin surface, though this fact may not be elicited by history. Modes of entry include minor abrasions after falling,¹ small wounds,² traumatic inoculation,¹⁵ and intramuscular injection.¹⁶ Clinically, cutaneous lesions of MAC are protean. In the literature, clinical presentation is described as a polymorphous appearance with scaling plaques, verrucous nodules, crusted ulcers, inflammatory nodules, dermatitis, panniculitis, draining sinuses, ecthymatous lesions, sporotrichoid growth patterns, or rosacealike papulopustules.^1,15,17 Lesions may affect the arms and legs, trunk, buttocks, and face.¹⁸

The differential diagnosis of MAC infection includes lupus vulgaris, Mycobacterium marinum infection (also known as swimming pool granuloma), sporotrichosis, nocardiosis, sarcoidosis, neutrophilic dermatosis, pyoderma gangrenosum, and cutaneous blastomycosis. Given its rarity and variability, diagnosis of MAC infection requires a high index of suspicion. Cutaneous MAC infection should be considered if a nodule, plaque, or ulcer fails to respond to conventional treatment, especially in patients with a history of environmental exposure and possible injury to the skin.

We report a rare case of primary cutaneous MAC infection arising in SCC excision sites in a patient without known immune deficiency. This presentation may have occurred for several reasons. First, the surgical excision sites coupled with the substantial occupational and recreational exposure to soil experienced by our patient may have served as portals for infection. Although SCCs are common on the hands, Mohs micrographic surgery is not always performed for excision; in our patient's case, this approach allowed for maximum tissue conservation and preserved manual function given the number and location of the lesions. Second, despite an overtly intact immune system, our patient may have harbored an occult immune deficiency, predisposing him to dermatologic infection with a microorganism of low intrinsic virulence and recurrent malignant neoplasms. This presentation may have been the first clinical indication of subtle immune compromise. For example, inadequate proinflammatory cytokines may contribute to both mycobacterial and malignant disease. A potential risk of inhibition of tumor necrosis factor α is the unmasking of tuberculosis or lymphoma.^19,20 Likewise, IFN-γ is vital in suppressing mycobacteria and malignancy. Yonekura et al²¹ found that IFN-γ induces apoptosis in oral SCC lines. It follows that a paucity of IFN-γ could allow neoplastic growth. Normal function of IFN-γ prompts microbicidal activity in macrophages and stimulates granuloma formation, both of which combat mycobacterial infection.¹⁹ A final postulation is that a simmering cutaneous MAC infection precipitated neoplastic degeneration into SCC, much the same way that the human papillomavirus has been correlated in the carcinogenesis of cervical cancer. As an intracellular microbe, MAC could cause the genetic machinery of skin cells to go awry. Kullavanijaya et al¹⁸ described a patient with cutaneous MAC in association with cervical cancer.

Conclusion

This association of primary cutaneous MAC infection and cutaneous malignancy in a reportedly immunocompetent patient is rare. Cancer patients, as noted by Feld et al,²² are 3 times more likely to develop infections with mycobacteria, with SCC, lymphoma, and leukemia being most commonly indicated. A specific immune deficit in the IFN-γ receptor is known to confer a selective predisposition to mycobacterial infection.^23,24 Toyoda et al²⁵ outlined the case of a pediatric patient with IFN-γ receptor 2 deficiency who presented with disseminated MAC infection and later succumbed to multiple SCCs of the hands and face. The authors' assertion was that inherited disorders of IFN-γ-mediated immunity may be associated with SCCs.²⁵ Unfortunately, our patient died before more specific immunological testing could be conducted. This case highlights the remarkable singularity of primary cutaneous MAC infection in association with multiple SCCs with seemingly intact immune status and offers some intriguing hypotheses regarding its occurrence.

Case Report

A 78-year-old man presented for evaluation of 4 painful keratotic nodules that had appeared on the dorsal aspect of the right thumb, the first web space of the right hand, and the first web space of the left hand. The nodules developed in pericicatricial skin following Mohs micrographic surgery to the affected areas for treatment of invasive squamous cell carcinomas (SCCs) 2 months prior. The patient had worked in lawn maintenance for decades and continued to garden on an avocational basis. He denied exposure to angling or aquariums.

On physical examination the lesions appeared as firm, dusky-violaceous, crusted nodules (Figure 1). Brown patches of hyperpigmentation or characteristic cornlike elevations of the palm were not present to implicate arsenic exposure. Extensive sun damage to the face, neck, forearms, and dorsal aspect of the hands was noted. Epitrochlear lymphadenopathy or lymphangitic streaking were not appreciated. Routine hematologic parameters including leukocyte count were normal, except for chronic thrombocytopenia. Computerized tomography of the abdomen demonstrated no hepatosplenomegaly or enlarged lymph nodes. Hematoxylin and eosin staining of biopsy specimens from the right thumb showed irregular squamous epithelial hyperplasia with an impetiginized scale crust and pustular tissue reaction, including suppurative abscess formation in the dermis (Figure 2). Initial acid-fast staining performed on the biopsy from the right thumb was negative for microorganisms. Given the concerning histologic features indicating infection, a tissue culture was performed. Subsequent growth on Lowenstein-Jensen culture medium confirmed infection with Mycobacterium avium complex (MAC). The patient was started on clarithromycin 500 mg twice daily in accordance with laboratory susceptibilities, and the cutaneous nodules improved. Unfortunately, the patient died 6 months later secondary to cardiac arrest.

Comment

The genus Mycobacterium comprises more than 130 described bacteria, including the precipitants of tuberculosis and leprosy. Mycobacterium avium complex--an umbrella term for M avium, Mycobacterium intracellulare, and other close relatives--is a member of the genus that maintains a low pathogenicity for healthy individuals.^1,2 Nonetheless, MAC accounts for more than 70% of cases of nontuberculous mycobacterial disease in the United States.³Mycobacterium avium complex typically acts as a respiratory pathogen, but infection may manifest with lymphadenitis, osteomyelitis, hepatosplenomegaly, or skin involvement. Disseminated MAC infection can occur in patients with defective immune systems, including those with conditions such as AIDS or hairy cell leukemia and those undergoing immunosuppressive therapy.^1,4 Although uncommon, cutaneous infection with MAC occurs via 3 possible mechanisms: (1) primary inoculation, (2) lymphogenous extension, or (3) hematologic dissemination.⁴ According to a PubMed search of articles indexed for MEDLINE using the terms primary cutaneous Mycobacterium avium complex and MAC skin infection, only 11 known cases of primary cutaneous MAC infection have been reported in the English-language literature,^4-14  the most recent being a report by Landriscina et al.¹¹

A Runyon group III bacillus, MAC is a slow-growing nonchromogen that is ubiquitous in nature.¹⁵ It has been isolated from soil, water, house dust, vegetables, eggs, and milk. According to Reed et al,³ occupational exposure to soil is an independent risk factor for MAC infection, with individuals reporting more than 6 years of cumulative participation in lawn and landscaping services, farming, or other occupations involving substantial exposure to dirt or dust most likely to be MAC-positive. Cutaneous MAC infection may be associated with water exposure, as Sugita et al² described one familial outbreak of cutaneous MAC infection linked to use of a circulating, constantly heated bathwater system. With respect to US geography, individuals living in rural areas of the South seem most prone to MAC infection.³

Primary cutaneous infection with MAC occurs after a breach in the skin surface, though this fact may not be elicited by history. Modes of entry include minor abrasions after falling,¹ small wounds,² traumatic inoculation,¹⁵ and intramuscular injection.¹⁶ Clinically, cutaneous lesions of MAC are protean. In the literature, clinical presentation is described as a polymorphous appearance with scaling plaques, verrucous nodules, crusted ulcers, inflammatory nodules, dermatitis, panniculitis, draining sinuses, ecthymatous lesions, sporotrichoid growth patterns, or rosacealike papulopustules.^1,15,17 Lesions may affect the arms and legs, trunk, buttocks, and face.¹⁸

The differential diagnosis of MAC infection includes lupus vulgaris, Mycobacterium marinum infection (also known as swimming pool granuloma), sporotrichosis, nocardiosis, sarcoidosis, neutrophilic dermatosis, pyoderma gangrenosum, and cutaneous blastomycosis. Given its rarity and variability, diagnosis of MAC infection requires a high index of suspicion. Cutaneous MAC infection should be considered if a nodule, plaque, or ulcer fails to respond to conventional treatment, especially in patients with a history of environmental exposure and possible injury to the skin.

We report a rare case of primary cutaneous MAC infection arising in SCC excision sites in a patient without known immune deficiency. This presentation may have occurred for several reasons. First, the surgical excision sites coupled with the substantial occupational and recreational exposure to soil experienced by our patient may have served as portals for infection. Although SCCs are common on the hands, Mohs micrographic surgery is not always performed for excision; in our patient's case, this approach allowed for maximum tissue conservation and preserved manual function given the number and location of the lesions. Second, despite an overtly intact immune system, our patient may have harbored an occult immune deficiency, predisposing him to dermatologic infection with a microorganism of low intrinsic virulence and recurrent malignant neoplasms. This presentation may have been the first clinical indication of subtle immune compromise. For example, inadequate proinflammatory cytokines may contribute to both mycobacterial and malignant disease. A potential risk of inhibition of tumor necrosis factor α is the unmasking of tuberculosis or lymphoma.^19,20 Likewise, IFN-γ is vital in suppressing mycobacteria and malignancy. Yonekura et al²¹ found that IFN-γ induces apoptosis in oral SCC lines. It follows that a paucity of IFN-γ could allow neoplastic growth. Normal function of IFN-γ prompts microbicidal activity in macrophages and stimulates granuloma formation, both of which combat mycobacterial infection.¹⁹ A final postulation is that a simmering cutaneous MAC infection precipitated neoplastic degeneration into SCC, much the same way that the human papillomavirus has been correlated in the carcinogenesis of cervical cancer. As an intracellular microbe, MAC could cause the genetic machinery of skin cells to go awry. Kullavanijaya et al¹⁸ described a patient with cutaneous MAC in association with cervical cancer.

Conclusion

This association of primary cutaneous MAC infection and cutaneous malignancy in a reportedly immunocompetent patient is rare. Cancer patients, as noted by Feld et al,²² are 3 times more likely to develop infections with mycobacteria, with SCC, lymphoma, and leukemia being most commonly indicated. A specific immune deficit in the IFN-γ receptor is known to confer a selective predisposition to mycobacterial infection.^23,24 Toyoda et al²⁵ outlined the case of a pediatric patient with IFN-γ receptor 2 deficiency who presented with disseminated MAC infection and later succumbed to multiple SCCs of the hands and face. The authors' assertion was that inherited disorders of IFN-γ-mediated immunity may be associated with SCCs.²⁵ Unfortunately, our patient died before more specific immunological testing could be conducted. This case highlights the remarkable singularity of primary cutaneous MAC infection in association with multiple SCCs with seemingly intact immune status and offers some intriguing hypotheses regarding its occurrence.