A rare case of primary malignant fibrous histiocytoma: a sarcoma of the kidney

BACKGROUND: Primary malignant fibrous histiocytoma of the kidney (MFH) is an extremely rare tumor which is indistinguishable from its’ mimics in particular renal cell carcinoma (RCC) by clinical features and preoperative imaging evaluation. Due to its high predilection to local recurrence and distant metastases, early diagnosis has great value. CASE PRESENTATION: Herein, we describe a 62 year-old man with a 3-month history of abdominal discomfort and a palpable right loin mass whom computerized tomography (CT) showed a large heterogeneous solid mass in the right kidney. With the suspicious to RCC; the patient underwent radical nephrectomy. However, histopathological report revealed pleomorphic-storiform malignant fibrous histiocytoma. Immunohistochemistry study was also confirmed the diagnosis of MFH. Six month follow up showed no evidence of any recurrence. CONCLUSIONS: The therapeutic options for MFH differ from other renal tumors, hence histopathology and immunohistochemistry studies are required to establish a definite diagnosis of the disease. Despite of progress made in clinical studies and advances in diagnostic modalities, early diagnosis of MFH has not achieved yet. Further studies and accumulated experience with renal MFH are required to determine the approach to prolong survival in selected cases along with management and prognostic factors of such tumors.