The elusive dermatofibromas.

Dermatofibromas skin lesions seen in a dermatology practice. They are well circumscribed, solitary or multiple, usually hyperpigmented dermal nodules, typically less than 1 cm in diameter. They may be slightly protuberant, but are most often flat, and are generally located on the extremities. One of the clinical attributes of dermatofibromas is their persistency, as they undergo few changes, if any, along a course of many years. The little variability of fully evolved dermatofibromas is the reason why in practice they are seldom excised, unless excision is requested by the patient for cosmetic or other reasons. The frequency of their presentation does not imply, however, that we fully understand their nature (neoplasia vs reactive process), their cell of origin (dermal histiocyte vs fibroblast), or their relationship with other dermal tumors. Proof of this ambivalence is the multiple synonyms used to describe them, including dermatofibroma, histiocytoma cutis , or fibrous histiocy-toma, as well as the now less frequently used nodular