Dermatology Online Journal

Multiple poromas in a bone marrow transplant recipient: A case report
Bichchau T Nguyen MD, David N Lortscher MD, Robert A Lee MD PhD
Dermatology Online Journal 18 (7): 9

Department of Medicine (Dermatology), University of California, San Diego, San Diego, California

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Abstract

A poroma is a benign epithelial neoplasm that most commonly presents as a solitary papule on the palm or sole. We report the case of a 25-year-old male, with a history of acute myelogenous leukemia, who developed multiple poromas on the feet. Poromatosis – the occurrence of multiple poromas – has been described in six adults and one child; it appears to be more prevalent in patients with a history of lymphoproliferative disorder or radiation exposure.

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Report of a case

A 25-year-old man presented to the dermatology clinic for evaluation of multiple papules on the dorsal, medial, and plantar surfaces of the feet. These papules had developed over 3 years, grew slowly, and were tender with touch and weight bearing. He denied any history of trauma or spontaneous bleeding. The lesions did not respond to over-the-counter salicylic acid. Of note, the patient had a history of acute myelogenous leukemia and had undergone autologous bone marrow transplantation nine years previously with complete remission.

Figure 1	Figure 2
Figure 1. Erythematous papules on the right medial foot Figure 2. Some lesions were surrounded by an epidermal collarette.

Examination revealed eight discrete, erythematous, dome-shaped papules distributed on the right dorsal foot, right medial foot, both soles, and both heels (Figure 1). Some of the lesions had an epidermal collarette (Figure 2). Shave biopsies of several papules were sent for pathologic examination.

Microscopic findings

Figure 3a	Figure 3b
Figures 3a and 3b. Hematoxylin-eosin stain reveals a well-circumscribed epithelial neoplasm with a highly vascularized stroma (A, x4). The lesion is composed of small, monomorphous, ovoid-to-cuboidal cells, and there are small ductal structures lined with an eosinophilic cuticle (B, x10).

Histopathology of each lesion reveals a well-circumscribed epithelial neoplasm extending from the epidermis in broad anastomosing bands. The lesions are made up of small, monomorphous, ovoid-to-cuboidal cells; there are small ductal structures lined with an eosinophilic cuticle and the stroma is highly vascularized (Figure 3). These microscopic findings are diagnostic of a poroma.

Discussion

Poromas are benign adnexal tumors that can have eccrine or apocrine origin [1]. They typically present as solitary, slow growing papules on the palms and soles, but less commonly on the head, neck, and trunk. Morphologically, poromas can resemble pyogenic granulomas, verrucae, seborrheic keratoses, or – if they are pigmented – melanomas. Adults are more frequently affected than children.

Poromatosis – the occurrence of multiple poromas – is very rare. The only reported case of pediatric poromatosis was an adolescent girl with hidrotic ectodermal dysplasia who presented with poromas on the extremities [2]. Of the six reported cases of adult poromatosis, four have been linked to a history of lymphoproliferative disorder or radiation exposure. One of these patients had mycosis fungoides and developed multiple poromas in areas treated with electron beam therapy over a course of 20 years [3]. Another patient developed localized poromatosis in areas of chronic radiation dermatitis from prior treatment for osteomyelitis [4]. Mahlberg et al. reported a middle aged man with acute lymphoid leukemia treated with total body irradiation and bone marrow transplantation complicated by graft-versus-host disease, who presented with mainly palmoplantar poromatosis [5]. Most recently, Navi et al. reported multiple poromas on the trunk and extremities of a 64-year-old man with a history of colorectal cancer and newly diagnosed non-Hodgkin lymphoma on chemotherapy [6]. Our patient was diagnosed with acute myelogenous leukemia 11 years ago and underwent autologous bone marrow transplantation with adjuvant chemotherapy but no radiation therapy. These cases suggest that poromatosis might be linked to either local or systemic immunosuppression via radiation, chemotherapy, or malignancy.

Removal of poromas is indicated to improve quality of life, given that they are often symptomatic and commonly found on acral surfaces. This can be accomplished by surgical excision or by shave removal with curettage and electrodessication of the base. It is unclear whether poromatosis increases the risk of porocarcinomas. There has been one report of co-existence of a poroma and two porocarcinomas in a linear epidermal nevus in an elderly woman [7]. Given the history of immunosuppression in a large proportion of adult patients affected with multiple poromas, these patients should have regular dermatologic examinations.

References

1. Harvell JD, Kerschmann RL, LeBoit PE. Eccrine or apocrine poroma? Six poromas with divergent adnexal differentiation. Am J Dermatopathol 1996; Feb;18(1):1-9. [PubMed]

2. Wilkinson RD, Schopflocher P, Rozenfeld M. Hidrotic ectodermal dysplasia with diffuse eccrine poromatosis. Arch Dermatol 1977; 113(4):472-6. [PubMed]

3. Kurokawa M, Amano M, Miyaguni H, et al. Eccrine poromas in a patient with mycosis fungoides treated with electron beam therapy. Br J Dermatol 2001; 145(5):830-3. [PubMed]

4. Ullah K, Pichler E, Fritsch P. Multiple eccrine poromas arising in chronic radiation dermatitis. Acta Derm Venereol 1989; 69(1):70-3. [PubMed]

5. Mahlberg MJ, McGinnis KS, Draft KS, Fakharzadeh SS. Multiple eccrine poromas in the setting of total body irradiation and immunosuppression. J Am Acad Dermatol 2006; 55(2 Suppl):S46-9. [PubMed]

6. Navi D, Fung M, Lynch PJ. Poromatosis: the occurrence of multiple eccrine poromas. Dermatol Online J 2008; 14(1):3. [PubMed]

7. Hamanaka S, Otsuka F. Multiple malignant eccrine poroma and a linear epidermal nevus. J Dermatol 1996; 23(7):469-71. [PubMed]

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