Dermatology Online Journal

Adenodermatofibroma is a newly recognized variant of fibrous histiocytoma (dermatofibroma), a benign lesion frequently encountered in dermatologic practice. There are many established variants of fibrous histiocytoma but there are only eight reported cases of this specific variant in the literature. This report reviews a case of an adenodermatofibroma presenting as a large, firm, atrophic plaque on the thigh. Histopathologic findings showed dilated glandular structures with apocrine features within a fibrohistiocytic cellular infiltrate, consistent with the diagnosis. We review the characteristic findings of adenodermatofibroma, discuss the differential diagnosis, and examine current theories speculating the origin of apocrine glands present within these lesions.