The squamous variant of eccrine porocarcinoma: a clinicopathological study of 21 cases.

AIM: Squamous differentiation in eccrine porocarcinoma (EPC) is an unusual phenomenon that has rarely been reported in the literature. This study describes the clinical and pathological findings in a series of 21 cases of EPC showing extensive squamous differentiation. METHODS: The H&E-stained sections, epithelial membrane antigen and carcinoembryonic antigen immunohistochemical stains were reviewed for each case. The following variables were examined: age, gender, race, site and size of the EPC. The prevalence of other cutaneous lesions and/or underlying systemic disease was also documented. RESULTS: There was an almost equal gender distribution. Mean age was 61.5 years and the average tumour size was 46.5 mm. An inordinately large number (10/21, 48%) of EPCs occurred in black patients. The tumours were located at various sites with the extremities predominating (10/19, 53%). Seven patients developed other sun-induced skin tumours, three patients were renal transplant recipients, and two patients were HIV-positive, one of whom also suffered from albinism. Six of the 11 patients in whom follow-up was available had an adverse outcome: local recurrence developed in one patient, one patient developed nodal metastases, and one patient experienced both local recurrence and nodal metastases, and of the three patients who died of disease, two developed distant metastases. CONCLUSION: The findings suggest a possible role for ultraviolet radiation and chronic immunosuppression in the induction of malignant squamous differentiation in a subset of EPCs. Further reports on this histological variant of EPC are required to determine whether a pathogenetic link does indeed exist or whether these tumours simply represent a unique variant of squamous cell carcinoma with divergent acrosyringial differentiation.

Eccrine porocarcinoma arising from preexisting eccrine poroma of the scalp after radiotherapy for cervical cancer.

Eccrine porocarcinoma may arise from eccrine poroma or it may occur de novo. We present a rapidly growing occipital malignant eccrine poroma on the scalp following to a radiotherapy for cervical carcinoma. A wide excision with skin grafting resulted no recurrence during a 1-year followup. Although malignant transformation is well known for other skin cancers this was not reported for eccrine poroma.

Multiple eccrine poromas in the setting of total body irradiation and immunosuppression.

Eccrine poromas are benign, adnexal tumors that most often occur as a solitary lesion on the palm or sole. The occurrence of multiple eccrine poromas is extremely rare. In this report, we describe the development of several eccrine poromas in an acral distribution in a 42-year-old man. Before the appearance of these tumors, the patient had received total body irradiation and allogeneic bone marrow transplantation for treatment of acute lymphocytic leukemia. As a complication of the bone marrow transplant, the patient developed chronic graft-versus-host disease, which was treated with immunosuppressive therapy. We discuss this patient and review the available literature regarding multiple eccrine poromas.

Eccrine poromas in a patient with mycosis fungoides treated with electron beam therapy.

We describe a 72-year-old man with mycosis fungoides (MF) followed up at our hospital for more than 20 years, who has developed 14 eccrine poromas (EPs) in the past 12 years. Twelve of these tumours were ascertained as EP histopathologically without any findings of malignancy and the other two were clinically diagnosed and are not yet resected. To our knowledge, this is the first case report of MF complicated with multiple EPs. In our patient, all EPs arose in skin areas previously irradiated with an electron beam for the treatment of MF, suggesting that electron beam irradiation might have an effect on the development of EPs.

Clear cell hidradenoma of the second digit: a review of the literature with case presentation.

Clear cell hidradenoma is a well circumscribed and often encapsulated benign tumor of the dermis and subcutaneous tissue. These tumors have a low tendency toward ulceration, may vary in size, and have a low malignant potential. The treatment of choice is usually surgical excision. A literature review of this soft tissue tumor and a case history are presented.