[A case of primary retroperitoneal malignant fibrous histiocytoma].

A 68-year-old man visited our hospital due to constipation. A hard mass was palpated in the left side abdomen. Several examinations could point out a large left sided retroperitoneal tumor. Because the tumor was adherent to the descending colon, both were removed. Based on histological and immunohistochemical inspection, the tumor was diagnosed as malignant fibrous histocytoma (MFH) on retroperitoneum. No treatment was undergone as the postoperative course was good, however, computed tomography (CT) for 8 months after the surgery showed the sign of local recurrence. It has been reported that the prognosis of MFH was very poor and a surgical resection was the only treatment for MFH, or we are expecting to find an effective treatment quickly such as a new combined chemotherapy.