Abstract
Purpose: Eccrine porocarcinoma is a very rare, potentially fatal tumor which arises from the intraepidermal portion of the eccrine sweat ductal apparatus. It does not have a characteristic clinical feature but does have a high incidence of metastasis. It may be developed de novo or in a preexisting benign eccrine poroma. It usually affects older people and is located most commonly on lower extremities. We report a rare case of eccrine porocarcinoma which developed on the back without metastasis. Methods: The patient was a 94-year-old woman who showed a painful, ulcerated, dark brown colored polypoid $3.5{\times}3.0cm$ sized mass on the back for 3 years. We totally excised the lesion including normal tissue. Results: After wide excision of the lesion, pathologist reported an eccrine porocarcinoma. Histopathologic findings reveal that the classic type of eccrine gland carcinoma, eccrine porocarcinoma. Immunocytochemical studies showed a positive reactivity to anti-EMA antibody and anti-CEA antibody. Conclusion: Authors experienced a rare case of primary eccrine porocarcinoma on the back. Because of the propensity to develop local recurrence, wide excision of the primary tumor with histologic confirmation of negative margins represents the only curative treatment regimen for eccrine porocarcinoma.