[A case of ureteral endometriosis; the usefulness of MRI for preoperative diagnosis].

A rare case of ureteral endometriosis is reported. A 46-year-old nulliparous woman was referred to our hospital because of right hydronephrosis which was detected by ultrasonography; Drip infusion pyelography showed right hydroureteronephrosis with the distal obstruction. MRI demonstrated right ovarian endometriosis and resultant ureteral stricture. Based on these findings, we made a preoperative diagnosis of right ureteral endometriosis. Right partial ureterectomy and ureteroureterostomy were performed. Pathological examination of the resected segment showed endometrial tissue around the ureteral lesion. She was administered LH-RH agonist (buserelin); her postoperative course was uneventful. IP showed no abnormalities 6 weeks after the operation. To our knowledge, this case is only the 55th case reported in the literature in Japan.