[A case report of malignant fibrous histiocytoma arising from the renal capsule].

A 58-year-old woman was found to have a tumor of the left kidney by ultrasonography and x-ray at a medical examination. Computed tomography showed a mass with calcification adjacent to the left kidney. The patient was successfully treated with open nephrectomy. Pathological examination revealed the malignant fibrous histiocytoma (MFH) arising from the renal capsule, striform-pleomorphic type, low grade malignancy. She was free of disease at fourteen months postoperatively. To our knowledge, this is the 26th case of MFH arising from the renal capsule in Japan.