[Bilateral multiple ureteral polyps causing intermittent hydronephrosis: a case report].

We report an unusual case of bilateral ureteral polyps causing intermittent hydronephrosis, which developed extensively in the upper part of ureters. The patient was an 8-year-old male. He had several episodes of gross hematuria with right flank pain. Ultrasonography of the kidney showed mild bilateral hydronephrosis, while this finding was markedly aggravated in association with the onset of pain. Intravenous pyelogram and retrograde pyelogram revealed multiple filling defects in both upper parts of ureters. Since the diseased part of the ureter was wide (about 7 cm in length), a segmental resection of the right ureter with mobilization of the right kidney was performed, followed by end-to-end ureteral anastomosis. The pathological diagnosis was fibroepithelial polyps. Regarding the disease of contralateral ureter, no surgical treatment was performed because he had no clinical symptoms. Six years after the surgery, he again developed gross hematuria with left flank pain. Marked dilatation of the left renal pelvis was shown by ultrasonography, which suggested left intermittent hydronephrosis caused by ureteral polyps. He underwent a partial ureterectomy with mobilization of the left kidney for the left ureteral disease. No recurrence of polyps has been observed in the urinary tract since this surgery.