Abstract
In general, the diagnosis of dermatofibrosarcoma protuberans is not difficult because of its characteristic clinical appearance. We report an unusual variant of dermatofibrosarcoma protuberans in a 19-year-old female. The lesion was a non-elevated and blue-colored subcutaneous tumor on the right upper arm. Histological examination showed the typical appearance of dermatofibrosarcoma protuberans. Tumor cells proliferated in the lower dermis and invaded into the subcutaneous tissue. They were composed of spindle-shaped tumor cells arranged in a storiform pattern HMB-45 positive and pigmented dendritic cells. Spindle-shaped tumor cells were positive for vimentin and CD34 and negative for factor XIIIa. The tumor was diagnosised as Non-protuberans Pigmented Dermatofibrosarcoma Protuberans (Bednar Tumor). These stainings were helpful in the diagnosis of this unusual variant of dermatofibrosarcoma protuberans. Dermatologists should recognize uncommon clinical appearance of dermatofibrosarcoma protuberans.
