Inflammatory pseudotumor of the kidney: report of a case with fine needle aspiration cytology.

We report a case of inflammatory pseudotumor of the kidney. A 73-year-old man presenting with general malaise and minimal grade fever visited a medical department in our hospital. Computerized tomography incidentally revealed a tumor, 3.5 cm in diameter, in the lower pole of the left kidney, and he was referred to our outpatient department. Selective left renal arteriography disclosed an avascular mass on the affected site. Left radical nephrectomy was performed under the diagnosis of avascular renal cell carcinoma. Histological examination demonstrated a tumor composed of spindle-shaped fibroblastic cells infiltrated by variable numbers of plasma cells, small lymphocytes and histiocytes. The pathologic diagnosis was renal inflammatory pseudotumor. Fourteen previously reported cases of this tumor have reviewed in the literature.