adnexal spiradenoma/cylindroma of a sweat gland
A benign sweat gland neoplasm usually occurring in the scalp or the face. It may present as solitary or multiple papular or nodular lesions. It may be a sporadic lesion or part of Brooke-Spiegler syndrome. It arises from the dermis and has a multinodular, circumscribed appearance. The nodules contain basaloid cells with small, dark nuclei. Complete excision is usually curative.