Sweat gland carcinoma with metastases to the skin: response to 5-fluorouracil chemotherapy.

A 68-year-old white man presented to the inpatient service at Columbia-Presbyterian Hospital with a chief complaint of a progressively enlarging tumor of the right infraorbital region for many years and multiple, pink papulonodules on his head, neck, and trunk. A biopsy specimen of the right infraorbital and back lesions demonstrated an infiltrating adenocarcinoma with prominent signet ring cells, and small lumen formation. Results of an extensive work-up revealed bone marrow metastases and no evidence of a primary malignancy. We present a case of primary sweat gland carcinoma with metastases to the skin based upon history, clinical presentation, results of physical examination, histopathologic examination, immunohistochemical studies, and response to 5-fluorouracil chemotherapy. Due to the rarity of the tumor, the diagnosis is usually not made until the tumor(s) is invasive. An excellent response to systemic chemotherapy with 5-fluorouracil in metastatic sweat gland carcinoma was noted in this case.