A case of cutaneous malignant fibrous histiocytoma.

A 54-year-old Japanese man with cutaneous malignant fibrous histiocytoma on the back is reported. He not only had a past history of thyroid cancer 1 year prior to the onset of the skin tumor, but also had simultaneous bladder cancer. Despite the early, wide resection, the prognosis was rapid and progressive. Histologically, the primary lesion of the skin tumor was difficult to differentiate from dermatofibrosarcoma protuberans; however, the recurrent and the metastatic lesions changed in appearance.