Follicular induction overlying a dermatofibrosarcoma protuberans.

The term "induction" has been used to describe epidermal changes overlying a dermatofibroma (DF). Follicular induction is most often associated with DF, but can be observed in other lesions, including focal mucinosis, nevus sebaceous, seborrheic keratosis, wart, neurofibroma, and scars. Dermatofibrosarcoma protuberans (DFSP) is a malignant fibrohistiocytic tumor that may be difficult to distinguish from DF. In contrast to DF, the epidermis overlying DFSP is usually attenuated or ulcerated. Here, we report a case of DFSP exhibiting follicular induction of the overlying epidermis. This epidermal change has been rarely reported in DFSP and may present a diagnostic pitfall in superficially sampled lesions.