Adnexal displacement and regression in association with histiocytoma (dermatofibroma).

The literature about the changes occurring in histiocytomas mentions only the possibility of induction of primitive pilosebaceous structures and basal cell epithelioma-like lesions by the histiofibrocytic growth. We suggest here that the histopathologic findings are indicative of regressive changes of the pre-existing cutaneous adnexa resulting in the formation of basal cell epithelioma-like structures.