[Intermittent hydronephrosis caused by ureteral polyp in childhood: report of a case].

We report a case of ureteral polyp causing intermittent hydronephrosis in a 12-year-old boy. He was often hospitalized with episodes of right flank pain and gross hematuria. An excretory urogram (IVP) revealed mild hydronephrosis, but it showed a markedly dilated right renal pelvis during the attack. An Anderson-Hynes type pyeloplasty was done. At operation we found four ureteral polyps, and performed partial ureterectomy including polyps. Pathological examination showed fibrous ureteral polyps. He has reported no symptoms for 3 months after the operation.