Adenoma of anogenital mammary-like glands.

Adenomas in the anogenital region are uncommon. There has been debate about the origin, including ectopic breast tissue, cutaneous apocrine gland, and most recently anogenital mammary-like gland. An anogenital mass in a 36-year-old woman was excised, and histopathologic examination and immunostaining were performed. Microscopic tissue sections showed a morphologic pattern similar to that of a mammary fibroadenoma, and immunostaining demonstrated the presence of estrogen receptors and progesterone receptors. The possibility of adenomas of anogenital mammary-like glands should be considered when evaluating patients with a mass in this area with confirmation by tissue biopsy or aspiration cytology.