Papillary eccrine adenoma. A histopathological and immunohistochemical study.

A case of papillary eccrine adenoma of the thigh of a 63-year-old woman is reported. Histologically, the tumor was composed of cystic dilated and branching tubular structures with papillary projections into the lumen, surrounded by a fibrous stroma. In addition, in some areas it was composed almost exclusively of solid strands of epithelial cells. The tumoral eccrine differentiation was assessed by immunohistochemical studies. Problems of differential diagnosis with low-grade sweat gland carcinoma and with tubular apocrine adenoma are discussed.