Giant-cell fibroblastoma with pigmented dermatofibrosarcoma protuberans component.

A unique case of giant-cell fibroblastoma that contained a pigmented dermatofibrosarcoma component (Bednár tumor) is described. The melanin pigmented dendritic cells found in the dermatofibrosarcoma component were round or spindle-shaped and had bipolar extensions. They were S-100 protein positive. Our case indicates the close histogenetic relationship between giant-cell fibroblastoma and dermatofibrosarcoma protuberans. The occurrence of the pigmented melanin-laden dendritic cells in our tumor further substantiates the theory that Bednár tumor is a pigmented variant of dermatofibrosarcoma protuberans.