[Retroperitoneal fibrosis suspected to be ureteral tumor because of its localization at the unilateral distal ureter: a case report].

The patient was a 32-year-old female with the complaint of right flank pain. Drip infusion pyelogram showed right hydronephrosis and retrograde urogram demonstrated a marked stenosis about 2 cm in length at the right distal ureter. The passage of the ureteral catheter and the contrast medium through the narrowing portion of the ureter could not be performed. The abdominal computerized tomographic (CT)-scan disclosed renal subcapsular urinoma, although no abnormal findings which caused ureteral stenosis were revealed. A suspicion of right ureteral tumor was entertained and total nephroureterectomy was performed. Histopathological diagnosis was the idiopathic retroperitoneal fibrosis, which involved the right ureter. One hundred and fifty five cases of idiopathic retroperitoneal fibrosis in the Japanese literature were reviewed.