Dermatology Online Journal

A two-year-old boy presented with a large, non-healing ulceration on his left buttock, which was originally noted as a brown patch present at birth. Punch skin biopsy was performed and histopathology revealed an atypical, pleomorphic, spindled proliferation in whorled fascicles replacing the dermis and trapping fat in the subcutis, consistent with a diagnosis of congenital/infantile fibrosarcoma. No evidence of metastatic spread was seen on imaging. The tumor was initially deemed unresectable owing to extent of local invasion. Neo-adjuvant chemotherapy caused significant tumor shrinkage and the patient underwent complete resection.