DEEP PENETRATING DERMATOFIBROMA

BACKGROUND. Deep penetrating dermatofibroma is an unusual and histolog ically distinctive form of dermatofibroma that usually occurs on the l ower extremities of adults. OBJECTIVE. The dermatologic surgeon and pa thologist should be aware of this entity to prevent excessive treatmen t of a benign condition. METHODS. We are reporting a case of deep pene trating dermatofibroma with the results of histologic examination and immunohistochemical studies. RESULTS. The neoplasm consisted of a fibr ohistiocytic tumor penetrating into the subcutis accompanied by scallo ped extensions along the septae. Immunohistochemical stains were posit ive for Factor XIIIa and negative for CD34. CONCLUSION. Recognition of the histologic pattern is important in distinguishing deep penetratin g dermatofibroma from dermatofibrosarcoma protuberans. (C) 1998 by the American Society for Dermatologic Surgery, Inc.