[A long ureteral polyp with ureteropelvic junction obstruction: report of a case].

A case of long ureteral polyp with ureteropelvic junction obstruction in a 29-year-old man is reported. He had complained of occasional left flank pain since several years earlier. Excretory urography showed left giant hydronephrosis and no urolithiasis. Retrograde pyelography revealed a mass lesion of the left upper ureter. At exploration, the left ureteropelvic junction was found to be obstructed by an aberrant lower pole renal vessel. At just distal of the junction, a finger-like ureteral polyp, 5 cm in maximal length, was present and accompanied with several little polyps. Partial ureterectomy and pyeloplasty improved the left hydronephrosis. The patient remains symptomless for one year after the operation.