Congenital dermatofibrosarcoma protuberans.

Congenital dermatofibrosarcoma protuberans (DFSP) is a rare dermal and subcutaneous neoplasm of low-grade malignant behavior that is characterized by a low frequency of metastases with locally invasive growth. Its occurrence at birth and during childhood is rare. We present a case of a patient who was born with a light brown macule on his right buttock that was misdiagnosed as localized scleroderma. The lesion progressed into reddish atrophic plaques and nodules extending to the iliac region and the gluteal fold. At 5 years of age, a diagnosis of congenital DFSP was made based on clinical and immunohistochemical characteristics (CD34 positivity and spindle cell proliferation). Although there was a delay in diagnosis, a 3-step excision was proposed with a final step of Mohs micrographic surgery (MMS).