Basal cell tumor with eccrine differentiation (eccrine epithelioma).

A case of eccrine epithelioma is presented. A 62-year-old woman was seen for with a lesion on the left forearm present for 36 years, and complicated by multiple recurrences. Histopathologically, it was composed of numerous small nests of basaloid cells, cystic and syringoid epithelial structures within the reticular dermis and invading the contiguous fat and muscle tissues. Tubular structures and cystic spaces contained PAS-positive, diastate-resistant, and alcian blue-positive material. Although the tumor was very aggressive locally, no metastasis had occurred throughout its long course.