This is a dermatofibrosarcoma protuberans (DFSP) and has recurred after previous surgical excision. A hint of the old surgical scar can be seen at one edge of the lesion. DFSPs commonly recur after standard surgical excision; the recurrence rate is 30-40% after standard excision, because lesions have extensions deep in the dermis and subcutaneous fat which cannot be appreciated by clinical examination. Click here for another view. This lesion was treated by Mohs surgery, which has a cure rate in excess of 95% for these lesions. Click here for a picture of the defect.