Primary renal malignant fibrous histiocytoma is an extremely rare disease. There are neither clinical nor radiological signs to distinguish it from the most common renal cell carcinoma. Its prognosis is poor because of its tendency to locally recur and metastasize. Therefore, early diagnosis and proper treatment are very important. We present the case of a 66-year-old woman diagnosed with primary renal malignant fibrous histiocytoma who underwent partial nephrectomy. After 41 months' follow-up, there was no evidence of any recurrence. To our knowledge, this is the first reported case of conservative surgery for this kind of tumor.
Keywords: Conservative renal surgery; Malignant fibrous histiocytoma; Sarcoma.