Atrophic dermatofibrosarcoma protuberans: an uncommon and misleading variant.

A 23-year-old man presented with an atrophic lesion on his left anterior shoulder that had been present for at least 10 years. A previous biopsy had suggested a fibrohistiocytic origin; however, clinically it resembled morphoea or atrophoderma, and the lesion was observed. Fifteen months later, the lesion was noted to have grown slightly. A repeat biopsy showed dermatofibrosarcoma protuberans, with a storiform spindle cell proliferation with positive CD34 staining. The lesion was excised with a 3-cm margin. Awareness of this rare presentation may assist in earlier diagnosis.