[A case of inflammatory myofibroblastic tumor recognized in the retroperitoneum and the kidney]

A 61-year-old man consulted his local physician because of abdominal pain and was referred to our hospital after bilateral renal tumors were suspected on CT. CT and MRI showed a tumor, approximately 3 cm in diameter in the right renal pelvis and a cyst in the left kidney. There were no malignant cells detected on cytological studies of two urine specimens that were voided commonly and obtained from the right renal pelvis, respectively. Under a diagnosis of right renal pelvic tumor, the patient underwent laparoscopic right nephroureterectomy. Pathological examination demonstrated two inflammatory myofibroblastic tumors; one was located in the upper portion of the right kidney and the other was in the fatty tissue of the right renal hilus. There has not been any evidence of recurrence detected on follow-up for three months postoperatively.