Pilary Complex Carcinoma: An Adnexal Carcinoma of the Skin with Differentiation towards the Components of the Pilary Complex

Homayoon Rahbari, M.D. and Amir H. Mehregan, M.D.
We report twelve cases with a distinctive form of adnexal carcinoma occurring most commonly over the head and neck of relatively old individuals. The growth was single in all cases, deep dermal in location, and consisted of massive proliferation of small basaloid cells with only occasional connection with the surface epidermis. The basaloid tumor masses showed only a few areas of palisading of their outer cell nuclei and occasional retraction space formation. The neoplasm revealed scattered areas of trichilemmal and epidermoid keratinization, foci of sebaceous, and areas of sweat ductal differentiation indicating participation of various components of the pilary complex.

Key Words: adnexal carcinoma-pilary complex; atypical basal cell epithelioma; adnexal differentiation; trichilemmal keratinization

JDA 1993;20:630-7