Recurrent polymorphous sweat gland carcinoma of the skin.

Polymorphous sweat gland carcinoma is an unusual, recently described variant of low-grade malignant adnexal neoplasm of the skin characterized by a prolonged clinical course and predilection for the extremities. We describe a case of recurrent polymorphous sweat gland carcinoma in a 56-year-old man who presented with multiple large skin nodules distributed along the flexor surface of his left arm. The lesions were treated by surgical excision; multiple local recurrences, as well as the development of new lesions, were observed over a period of 5 years. No distant metastases have been observed so far. The clinical differential diagnosis and management of these unusual lesions are discussed.