A Case of Microcystic Adnexal Carcinoma on the Scalp / 대한피부과학회지

ABSTRACT

Microcystic adnexal carcinoma is a rare, locally aggressive tumor with a high potential for local recurrence. It usually presents in elderly patients as a solitary, slowly growing, firm, indurated plaque on the face, and particularly on the upper lip or central face. It has occasionally been found in extra-facial locations, including the nipple, axilla and lower extremities, yet scalp involvement has been rarely reported. Histopathologically, it is a poorly circumscribed dermal tumor that shows both follicular and ductal differentiation, and it may extend into the subcutis and skeletal muscle. We report here on a case of microcystic adnexal carcinoma at an unusual site the scalp. A 42-year-old woman presented with a 6-month history of a painful, solitary, 1 cm-sized, firm, fixed, dome-shaped nodule on the scalp, and this was accompanied by ulceration and oozing. A biopsy specimen demonstrated features of microcystic adnexal carcinoma, with both follicular and ductal differentiation. Immunohistochemical staining for CEA (carcinoembryonic antigen) was positive in the ductal structures, but this was negative in the follicular structures.