Cutis

To the Editor:

Erythema ab igne (EAI) is a reticular erythematous hyperpigmentation of skin repeatedly exposed to moderate heat.¹ It usually is asymptomatic, though some patients report itching or burning at the site.² Historically caused by exposure to coal stoves or open fires, EAI has become increasingly common among individuals using space heaters, heating pads, or laptop computers near bare skin.^2,3 Although EAI itself is benign and usually resolves with the removal of the exposure, it remains of clinical importance because of its association with underlying chronic disease, as chronic pain often is managed with frequent heating pad or hot water bottle use.² Additionally, accurate diagnosis is important given the future risk for malignancy, as chronic changes of EAI have been reported to lead to squamous cell carcinoma or rarely Merkel cell carcinoma.² Erythema ab igne is not traditionally associated with the formation of bullae; however, we present a case of bullous EAI that we believe highlights the importance of including this condition in the differential diagnosis of bullous disorders.

A 55-year-old man was admitted for presumed cellulitis of the bilateral legs. The patient had developed hyperpigmented discoloration of the medial surface of both legs with subsequent formation of tense bullae over the last 2 months. The dermatology department was consulted, as there was concern for bullous pemphigoid. The patient’s medical history was notable for hypertension, hyperlipidemia, diet-controlled type 2 diabetes mellitus, and hepatitis C virus with cirrhosis. The patient denied pruritus, pain, or known exposure of the legs to potential irritants prior to developing the lesions; however, with additional questioning he did report frequently sitting in front of a space heater with bare legs. Physical examination revealed multiple areas of reticulated erythematous hyperpigmentation with several overlying bullae (Figure 1). Many of the bullae were unroofed with full-thickness ulceration. Biopsies were taken for hematoxylin and eosin staining (Figure 2) and direct immunofluorescence.

Basic hematologic and metabolic laboratory test results as well as blood cultures were negative. Wound culture was positive for methicillin-resistant Staphylococcus aureus. Histologic examination showed interface dermatitis with subepidermal vesicle (Figure 2). Scattered necrotic keratinocytes were present in the adjacent epidermis, and focal subtle vacuolar alteration of the dermoepidermal junction was seen (Figure 3). Sparse perivascular mononuclear cells and scattered melanophages were present in the dermis. Direct immunofluorescence showed no diagnostic immunopathologic abnormality. Focal weak nonspecific vascular positivity for IgG and C3 was seen, but IgA and IgM were negative. Although not specific, these changes were compatible with EAI in the clinical context provided. The diagnosis of bullous EAI with superimposed staphylococcal infection was made.

Although rare, there have been reports of a bullous variant of EAI. Flanagan et al⁴ described 3 cases of bullous EAI with histopathology similar to our case. All 3 biopsies showed subepidermal separation with a mild perivascular dermal lymphocytic infiltrate. Direct immunofluorescence was negative in 2 cases but showed nonspecific weak patchy deposition of IgM along the dermoepidermal junction.⁴ Although our case was negative for IgM, there was a similar weak nonspecific distribution of IgG. Kokturk et al⁵ described a case of bullous EAI in a man with repeated exposure to a space heater. The lesions showed subepidermal separation of the epidermis; increased elastic fibers; dilated dermal capillaries; melanophages in the upper dermis; and a mild, superficial, perivascular-lymphocytic infiltrate. Direct immunofluorescence showed no immune deposits.⁵ Several earlier cases of bullae associated with EAI have been reported in the literature but were thought to be bullous lichen planus superimposed on EAI.⁶ Our case, which exhibited similar historical, physical, and histopathologic findings, strengthens the argument for a defined bullous variant of EAI.

To the Editor:

Erythema ab igne (EAI) is a reticular erythematous hyperpigmentation of skin repeatedly exposed to moderate heat.¹ It usually is asymptomatic, though some patients report itching or burning at the site.² Historically caused by exposure to coal stoves or open fires, EAI has become increasingly common among individuals using space heaters, heating pads, or laptop computers near bare skin.^2,3 Although EAI itself is benign and usually resolves with the removal of the exposure, it remains of clinical importance because of its association with underlying chronic disease, as chronic pain often is managed with frequent heating pad or hot water bottle use.² Additionally, accurate diagnosis is important given the future risk for malignancy, as chronic changes of EAI have been reported to lead to squamous cell carcinoma or rarely Merkel cell carcinoma.² Erythema ab igne is not traditionally associated with the formation of bullae; however, we present a case of bullous EAI that we believe highlights the importance of including this condition in the differential diagnosis of bullous disorders.

A 55-year-old man was admitted for presumed cellulitis of the bilateral legs. The patient had developed hyperpigmented discoloration of the medial surface of both legs with subsequent formation of tense bullae over the last 2 months. The dermatology department was consulted, as there was concern for bullous pemphigoid. The patient’s medical history was notable for hypertension, hyperlipidemia, diet-controlled type 2 diabetes mellitus, and hepatitis C virus with cirrhosis. The patient denied pruritus, pain, or known exposure of the legs to potential irritants prior to developing the lesions; however, with additional questioning he did report frequently sitting in front of a space heater with bare legs. Physical examination revealed multiple areas of reticulated erythematous hyperpigmentation with several overlying bullae (Figure 1). Many of the bullae were unroofed with full-thickness ulceration. Biopsies were taken for hematoxylin and eosin staining (Figure 2) and direct immunofluorescence.

Basic hematologic and metabolic laboratory test results as well as blood cultures were negative. Wound culture was positive for methicillin-resistant Staphylococcus aureus. Histologic examination showed interface dermatitis with subepidermal vesicle (Figure 2). Scattered necrotic keratinocytes were present in the adjacent epidermis, and focal subtle vacuolar alteration of the dermoepidermal junction was seen (Figure 3). Sparse perivascular mononuclear cells and scattered melanophages were present in the dermis. Direct immunofluorescence showed no diagnostic immunopathologic abnormality. Focal weak nonspecific vascular positivity for IgG and C3 was seen, but IgA and IgM were negative. Although not specific, these changes were compatible with EAI in the clinical context provided. The diagnosis of bullous EAI with superimposed staphylococcal infection was made.

Although rare, there have been reports of a bullous variant of EAI. Flanagan et al⁴ described 3 cases of bullous EAI with histopathology similar to our case. All 3 biopsies showed subepidermal separation with a mild perivascular dermal lymphocytic infiltrate. Direct immunofluorescence was negative in 2 cases but showed nonspecific weak patchy deposition of IgM along the dermoepidermal junction.⁴ Although our case was negative for IgM, there was a similar weak nonspecific distribution of IgG. Kokturk et al⁵ described a case of bullous EAI in a man with repeated exposure to a space heater. The lesions showed subepidermal separation of the epidermis; increased elastic fibers; dilated dermal capillaries; melanophages in the upper dermis; and a mild, superficial, perivascular-lymphocytic infiltrate. Direct immunofluorescence showed no immune deposits.⁵ Several earlier cases of bullae associated with EAI have been reported in the literature but were thought to be bullous lichen planus superimposed on EAI.⁶ Our case, which exhibited similar historical, physical, and histopathologic findings, strengthens the argument for a defined bullous variant of EAI.

To the Editor:

Erythema ab igne (EAI) is a reticular erythematous hyperpigmentation of skin repeatedly exposed to moderate heat.¹ It usually is asymptomatic, though some patients report itching or burning at the site.² Historically caused by exposure to coal stoves or open fires, EAI has become increasingly common among individuals using space heaters, heating pads, or laptop computers near bare skin.^2,3 Although EAI itself is benign and usually resolves with the removal of the exposure, it remains of clinical importance because of its association with underlying chronic disease, as chronic pain often is managed with frequent heating pad or hot water bottle use.² Additionally, accurate diagnosis is important given the future risk for malignancy, as chronic changes of EAI have been reported to lead to squamous cell carcinoma or rarely Merkel cell carcinoma.² Erythema ab igne is not traditionally associated with the formation of bullae; however, we present a case of bullous EAI that we believe highlights the importance of including this condition in the differential diagnosis of bullous disorders.

A 55-year-old man was admitted for presumed cellulitis of the bilateral legs. The patient had developed hyperpigmented discoloration of the medial surface of both legs with subsequent formation of tense bullae over the last 2 months. The dermatology department was consulted, as there was concern for bullous pemphigoid. The patient’s medical history was notable for hypertension, hyperlipidemia, diet-controlled type 2 diabetes mellitus, and hepatitis C virus with cirrhosis. The patient denied pruritus, pain, or known exposure of the legs to potential irritants prior to developing the lesions; however, with additional questioning he did report frequently sitting in front of a space heater with bare legs. Physical examination revealed multiple areas of reticulated erythematous hyperpigmentation with several overlying bullae (Figure 1). Many of the bullae were unroofed with full-thickness ulceration. Biopsies were taken for hematoxylin and eosin staining (Figure 2) and direct immunofluorescence.

Basic hematologic and metabolic laboratory test results as well as blood cultures were negative. Wound culture was positive for methicillin-resistant Staphylococcus aureus. Histologic examination showed interface dermatitis with subepidermal vesicle (Figure 2). Scattered necrotic keratinocytes were present in the adjacent epidermis, and focal subtle vacuolar alteration of the dermoepidermal junction was seen (Figure 3). Sparse perivascular mononuclear cells and scattered melanophages were present in the dermis. Direct immunofluorescence showed no diagnostic immunopathologic abnormality. Focal weak nonspecific vascular positivity for IgG and C3 was seen, but IgA and IgM were negative. Although not specific, these changes were compatible with EAI in the clinical context provided. The diagnosis of bullous EAI with superimposed staphylococcal infection was made.

Although rare, there have been reports of a bullous variant of EAI. Flanagan et al⁴ described 3 cases of bullous EAI with histopathology similar to our case. All 3 biopsies showed subepidermal separation with a mild perivascular dermal lymphocytic infiltrate. Direct immunofluorescence was negative in 2 cases but showed nonspecific weak patchy deposition of IgM along the dermoepidermal junction.⁴ Although our case was negative for IgM, there was a similar weak nonspecific distribution of IgG. Kokturk et al⁵ described a case of bullous EAI in a man with repeated exposure to a space heater. The lesions showed subepidermal separation of the epidermis; increased elastic fibers; dilated dermal capillaries; melanophages in the upper dermis; and a mild, superficial, perivascular-lymphocytic infiltrate. Direct immunofluorescence showed no immune deposits.⁵ Several earlier cases of bullae associated with EAI have been reported in the literature but were thought to be bullous lichen planus superimposed on EAI.⁶ Our case, which exhibited similar historical, physical, and histopathologic findings, strengthens the argument for a defined bullous variant of EAI.

To the Editor:

Paraneoplastic acrokeratosis (PA), also known as Bazex syndrome, is a rare paraneoplastic dermatosis first described in 1965 by Bazex et al.¹ This entity is clinically characterized by dusky erythematous to violaceous keratoderma of the acral sites and commonly affects men older than 40 years. In most reported cases, there has been an underlying primary malignant neoplasm of the upper aerodigestive tract²; however, some other associated malignancies also have been reported. Skin changes tend to occur before the diagnosis of the associated tumor in 67% of cases. The cutaneous lesions usually resolve after successful treatment of the tumor and relapse in case of recurrence of the malignancy.³

A 53-year-old woman who was a smoker with no relevant medical background was referred to the dermatology department with an itching psoriasiform dermatitis on the palms and soles of 2 months' duration. There were no signs of systemic disease. Physical examination revealed well-demarcated, dusky red, thick, scaly plaques on the soles with sparing of the insteps (Figure, A). Scattered symmetric hyperkeratotic plaques were present on the palms (Figure, B). We also detected onychodystrophy on the hands. Other dermatologic findings were normal. Histologic examination of a biopsy specimen of the left sole showed hyperkeratosis, focal parakeratosis, acanthosis, hypergranulosis, and a predominantly perivascular dermal lymphocytic infiltrate.

With the diagnostic suspicion of PA, blood tests, chest radiograph, and colonoscopy were performed without revealing abnormalities. Positron emission tomography and computed tomography also was performed, showing cervical, mesenteric, retroperitoneal, and inguinal adenopathies. Histologic examination of both inguinal adenectomy and cervical lymph node biopsy revealed Bcl-2-positive in situ follicular lymphoma (ISFL). Examination of an iliac crest marrow aspirate showed minimal involvement of lymphoma (10%). Follow-up imaging performed 4 months after diagnosis showed no changes. The patient was diagnosed with a low-grade chronic lymphoproliferative disorder with histologic findings consistent with ISFL presenting with small disperse adenopathies and minimal bone marrow involvement. The hematology department opted for a wait-and-see approach with 6-month follow-up imaging.

The skin lesions were first treated with salicylic acid cream 10%, psoralen plus UVA therapy, and methotrexate 20 mg weekly for 2 months without remission. Replacing the other therapies, we initiated acitretin 25 mg daily, achieving sustained remission after 6 months of treatment, and then continued with a scaled dose reduction. The patient remained lesion free 1 year after starting the treatment, with a daily dose of 10 mg of acitretin.

Paraneoplastic acrokeratosis has been traditionally described as a paraneoplastic entity mainly associated with primary squamous cell carcinoma (SCC) of the upper aerodigestive tract or a metastatic SCC of the cervical lymph nodes with an unknown origin.^4,5 However, uncommon associations such as adenocarcinoma of the prostate, lung, esophagus, stomach, and colon; transitional cell carcinoma of the bladder; small cell carcinoma of the lung; cutaneous SCC; breast cancer; metastatic thymic carcinoma; metastatic neuroendocrine tumor; bronchial carcinoid tumor; SCC of the vulvar region; simultaneous multiple genitourinary tumors; and liposarcoma also have been described.⁶ Regarding the association with lymphoma, PA has been reported with peripheral T-cell lymphoma⁷ and Hodgkin disease⁸; however, ISFL underlying PA is rare.

Follicular lymphoma is the second most common non-Hodgkin lymphoma in Western countries and comprises approximately 20% of all lymphomas.⁹ It is slightly more prevalent in females, and the majority of patients present with advanced-stage disease. Generally considered to be an incurable disease, a watchful-waiting approach of conservative management has been advocated in most cases, deferring treatment until symptoms appear.⁹

Histology of PA is nonspecific, as in our case. However, it facilitates a differential diagnosis of major dermatoses including psoriasis vulgaris, pityriasis rubra pilaris, and lupus erythematosus.

Paraneoplastic palmoplantar keratoderma also is characteristic of Howel-Evans syndrome, which is a rare inherited condition associated with esophageal cancer. In contrast to our case, palmoplantar keratoderma in these patients usually begins around 10 years of age, is caused by a mutation in the RHBDF2 gene, and is inherited in an autosomal pattern.¹⁰

The diagnosis in our case was supported by a typical clinical picture, nonspecific histology, and the concurrent finding of the underlying lymphoma. Treatment of PA must focus on the removal of the underlying malignancy, which implies the remission of the cutaneous lesions. Taking into account that a recurrence of the primary tumor leads to a relapse of skin manifestations while distant metastases do not cause a reappearance of PA, it could be suggested that pathogenetically relevant factors are produced by the primary tumor and by lymph node metastases but not by metastases elsewhere.

In this case, due to the wait-and-see approach, a specific treatment for the skin lesions was established. Although management of the skin itself generally is ineffective, there are isolated reports of response after corticosteroids, antibiotics, antimycotics, keratolytic measures, or psoralen plus UVA therapy.⁶ Wishart¹¹ used etretinate to achieve an improvement of PA. We also achieved good response with acitretin. Retinoids are known to have antineoplastic activity, which may have been helpful in both the patient we presented and the one reported by Wishart.¹¹ In summary, we propose adding ISFL to the expanding list of malignant neoplasms associated with PA, noting the response of skin lesions after acitretin.

To the Editor:

Paraneoplastic acrokeratosis (PA), also known as Bazex syndrome, is a rare paraneoplastic dermatosis first described in 1965 by Bazex et al.¹ This entity is clinically characterized by dusky erythematous to violaceous keratoderma of the acral sites and commonly affects men older than 40 years. In most reported cases, there has been an underlying primary malignant neoplasm of the upper aerodigestive tract²; however, some other associated malignancies also have been reported. Skin changes tend to occur before the diagnosis of the associated tumor in 67% of cases. The cutaneous lesions usually resolve after successful treatment of the tumor and relapse in case of recurrence of the malignancy.³

A 53-year-old woman who was a smoker with no relevant medical background was referred to the dermatology department with an itching psoriasiform dermatitis on the palms and soles of 2 months' duration. There were no signs of systemic disease. Physical examination revealed well-demarcated, dusky red, thick, scaly plaques on the soles with sparing of the insteps (Figure, A). Scattered symmetric hyperkeratotic plaques were present on the palms (Figure, B). We also detected onychodystrophy on the hands. Other dermatologic findings were normal. Histologic examination of a biopsy specimen of the left sole showed hyperkeratosis, focal parakeratosis, acanthosis, hypergranulosis, and a predominantly perivascular dermal lymphocytic infiltrate.

With the diagnostic suspicion of PA, blood tests, chest radiograph, and colonoscopy were performed without revealing abnormalities. Positron emission tomography and computed tomography also was performed, showing cervical, mesenteric, retroperitoneal, and inguinal adenopathies. Histologic examination of both inguinal adenectomy and cervical lymph node biopsy revealed Bcl-2-positive in situ follicular lymphoma (ISFL). Examination of an iliac crest marrow aspirate showed minimal involvement of lymphoma (10%). Follow-up imaging performed 4 months after diagnosis showed no changes. The patient was diagnosed with a low-grade chronic lymphoproliferative disorder with histologic findings consistent with ISFL presenting with small disperse adenopathies and minimal bone marrow involvement. The hematology department opted for a wait-and-see approach with 6-month follow-up imaging.

The skin lesions were first treated with salicylic acid cream 10%, psoralen plus UVA therapy, and methotrexate 20 mg weekly for 2 months without remission. Replacing the other therapies, we initiated acitretin 25 mg daily, achieving sustained remission after 6 months of treatment, and then continued with a scaled dose reduction. The patient remained lesion free 1 year after starting the treatment, with a daily dose of 10 mg of acitretin.

Paraneoplastic acrokeratosis has been traditionally described as a paraneoplastic entity mainly associated with primary squamous cell carcinoma (SCC) of the upper aerodigestive tract or a metastatic SCC of the cervical lymph nodes with an unknown origin.^4,5 However, uncommon associations such as adenocarcinoma of the prostate, lung, esophagus, stomach, and colon; transitional cell carcinoma of the bladder; small cell carcinoma of the lung; cutaneous SCC; breast cancer; metastatic thymic carcinoma; metastatic neuroendocrine tumor; bronchial carcinoid tumor; SCC of the vulvar region; simultaneous multiple genitourinary tumors; and liposarcoma also have been described.⁶ Regarding the association with lymphoma, PA has been reported with peripheral T-cell lymphoma⁷ and Hodgkin disease⁸; however, ISFL underlying PA is rare.

Follicular lymphoma is the second most common non-Hodgkin lymphoma in Western countries and comprises approximately 20% of all lymphomas.⁹ It is slightly more prevalent in females, and the majority of patients present with advanced-stage disease. Generally considered to be an incurable disease, a watchful-waiting approach of conservative management has been advocated in most cases, deferring treatment until symptoms appear.⁹

Histology of PA is nonspecific, as in our case. However, it facilitates a differential diagnosis of major dermatoses including psoriasis vulgaris, pityriasis rubra pilaris, and lupus erythematosus.

Paraneoplastic palmoplantar keratoderma also is characteristic of Howel-Evans syndrome, which is a rare inherited condition associated with esophageal cancer. In contrast to our case, palmoplantar keratoderma in these patients usually begins around 10 years of age, is caused by a mutation in the RHBDF2 gene, and is inherited in an autosomal pattern.¹⁰

The diagnosis in our case was supported by a typical clinical picture, nonspecific histology, and the concurrent finding of the underlying lymphoma. Treatment of PA must focus on the removal of the underlying malignancy, which implies the remission of the cutaneous lesions. Taking into account that a recurrence of the primary tumor leads to a relapse of skin manifestations while distant metastases do not cause a reappearance of PA, it could be suggested that pathogenetically relevant factors are produced by the primary tumor and by lymph node metastases but not by metastases elsewhere.

In this case, due to the wait-and-see approach, a specific treatment for the skin lesions was established. Although management of the skin itself generally is ineffective, there are isolated reports of response after corticosteroids, antibiotics, antimycotics, keratolytic measures, or psoralen plus UVA therapy.⁶ Wishart¹¹ used etretinate to achieve an improvement of PA. We also achieved good response with acitretin. Retinoids are known to have antineoplastic activity, which may have been helpful in both the patient we presented and the one reported by Wishart.¹¹ In summary, we propose adding ISFL to the expanding list of malignant neoplasms associated with PA, noting the response of skin lesions after acitretin.

To the Editor:

Paraneoplastic acrokeratosis (PA), also known as Bazex syndrome, is a rare paraneoplastic dermatosis first described in 1965 by Bazex et al.¹ This entity is clinically characterized by dusky erythematous to violaceous keratoderma of the acral sites and commonly affects men older than 40 years. In most reported cases, there has been an underlying primary malignant neoplasm of the upper aerodigestive tract²; however, some other associated malignancies also have been reported. Skin changes tend to occur before the diagnosis of the associated tumor in 67% of cases. The cutaneous lesions usually resolve after successful treatment of the tumor and relapse in case of recurrence of the malignancy.³

A 53-year-old woman who was a smoker with no relevant medical background was referred to the dermatology department with an itching psoriasiform dermatitis on the palms and soles of 2 months' duration. There were no signs of systemic disease. Physical examination revealed well-demarcated, dusky red, thick, scaly plaques on the soles with sparing of the insteps (Figure, A). Scattered symmetric hyperkeratotic plaques were present on the palms (Figure, B). We also detected onychodystrophy on the hands. Other dermatologic findings were normal. Histologic examination of a biopsy specimen of the left sole showed hyperkeratosis, focal parakeratosis, acanthosis, hypergranulosis, and a predominantly perivascular dermal lymphocytic infiltrate.

With the diagnostic suspicion of PA, blood tests, chest radiograph, and colonoscopy were performed without revealing abnormalities. Positron emission tomography and computed tomography also was performed, showing cervical, mesenteric, retroperitoneal, and inguinal adenopathies. Histologic examination of both inguinal adenectomy and cervical lymph node biopsy revealed Bcl-2-positive in situ follicular lymphoma (ISFL). Examination of an iliac crest marrow aspirate showed minimal involvement of lymphoma (10%). Follow-up imaging performed 4 months after diagnosis showed no changes. The patient was diagnosed with a low-grade chronic lymphoproliferative disorder with histologic findings consistent with ISFL presenting with small disperse adenopathies and minimal bone marrow involvement. The hematology department opted for a wait-and-see approach with 6-month follow-up imaging.

The skin lesions were first treated with salicylic acid cream 10%, psoralen plus UVA therapy, and methotrexate 20 mg weekly for 2 months without remission. Replacing the other therapies, we initiated acitretin 25 mg daily, achieving sustained remission after 6 months of treatment, and then continued with a scaled dose reduction. The patient remained lesion free 1 year after starting the treatment, with a daily dose of 10 mg of acitretin.

Paraneoplastic acrokeratosis has been traditionally described as a paraneoplastic entity mainly associated with primary squamous cell carcinoma (SCC) of the upper aerodigestive tract or a metastatic SCC of the cervical lymph nodes with an unknown origin.^4,5 However, uncommon associations such as adenocarcinoma of the prostate, lung, esophagus, stomach, and colon; transitional cell carcinoma of the bladder; small cell carcinoma of the lung; cutaneous SCC; breast cancer; metastatic thymic carcinoma; metastatic neuroendocrine tumor; bronchial carcinoid tumor; SCC of the vulvar region; simultaneous multiple genitourinary tumors; and liposarcoma also have been described.⁶ Regarding the association with lymphoma, PA has been reported with peripheral T-cell lymphoma⁷ and Hodgkin disease⁸; however, ISFL underlying PA is rare.

Follicular lymphoma is the second most common non-Hodgkin lymphoma in Western countries and comprises approximately 20% of all lymphomas.⁹ It is slightly more prevalent in females, and the majority of patients present with advanced-stage disease. Generally considered to be an incurable disease, a watchful-waiting approach of conservative management has been advocated in most cases, deferring treatment until symptoms appear.⁹

Histology of PA is nonspecific, as in our case. However, it facilitates a differential diagnosis of major dermatoses including psoriasis vulgaris, pityriasis rubra pilaris, and lupus erythematosus.

Paraneoplastic palmoplantar keratoderma also is characteristic of Howel-Evans syndrome, which is a rare inherited condition associated with esophageal cancer. In contrast to our case, palmoplantar keratoderma in these patients usually begins around 10 years of age, is caused by a mutation in the RHBDF2 gene, and is inherited in an autosomal pattern.¹⁰

The diagnosis in our case was supported by a typical clinical picture, nonspecific histology, and the concurrent finding of the underlying lymphoma. Treatment of PA must focus on the removal of the underlying malignancy, which implies the remission of the cutaneous lesions. Taking into account that a recurrence of the primary tumor leads to a relapse of skin manifestations while distant metastases do not cause a reappearance of PA, it could be suggested that pathogenetically relevant factors are produced by the primary tumor and by lymph node metastases but not by metastases elsewhere.

In this case, due to the wait-and-see approach, a specific treatment for the skin lesions was established. Although management of the skin itself generally is ineffective, there are isolated reports of response after corticosteroids, antibiotics, antimycotics, keratolytic measures, or psoralen plus UVA therapy.⁶ Wishart¹¹ used etretinate to achieve an improvement of PA. We also achieved good response with acitretin. Retinoids are known to have antineoplastic activity, which may have been helpful in both the patient we presented and the one reported by Wishart.¹¹ In summary, we propose adding ISFL to the expanding list of malignant neoplasms associated with PA, noting the response of skin lesions after acitretin.