Primary malignant fibrous histiocytoma of the kidney: report of a case and literature review.

We report a 44-year-old woman with a malignant fibrous histiocytoma (MFH) of the kidney. Primary renal MFH is an extremely rare tumor with a poor prognosis. Renal MFH is differentiated from renal cell carcinoma, renal sarcoma, and sarcomatoid renal tumors only by histological and immunohistochemical studies. Because the therapeutic options for MFH are different, its early diagnosis is imperative.