Pigmented dermatofibrosarcoma protuberans (Bednár tumor). An autopsy case with systemic metastasis

An autopsy case of pigmented dermatofibrosarcoma protuberans (Bednár tumor) with systemic metastasis is reported. No previous example of this tumor showing widespread metastasis has been reported in the literature. The patient, a 45-year-old man, developed a tumor on the right upper arm. The tumor recurred twice and metastasized to other parts of the skin, lungs and brain during the 8-year clinical course. The primary tumor contained melanin-laden tumor cells and showed a storiform growth pattern. Autopsy confirmed multiple metastatic lesions in the skin, lungs, brain, thyroid, pancreas, stomach, small intestine and thigh muscles. The recurrent and metastatic tumors lacked both melanin production and the storiform arrangement, and instead revealed "fibro-sarcomatous" change with a herring-bone or interlacing pattern of growth.