Blind-ending duplicate ureter with giant cystic dilatation

Blind-ending ureter is a rare ureteric duplication anomaly. Most cases are asymptomatic and are detected incidentally. Blind-ending ureter with a huge cystic dilatation is extremely unusual. A 46-year-old man with a complaint of low back pain was referred from the neurosurgery department upon demonstration of a large cystic mass in the retroperitoneum by lumbar magnetic resonance imaging. Ultrasonography showed a large cystic mass filling the right side of the abdomen and the entire pelvis. Intravenous urography showed malrotation and lateral deviation of the right kidney with grade 1 hydronephrosis, severe dilatation of the ureter with proximal kinking, and medial deviation of the ureter. Computed tomography revealed a huge cystic mass beginning at the medial aspect of the upper pole of the right kidney, filling the right half of the abdomen and all the pelvis. The cyst had septations in the pelvis. Cyst aspiration yielded no atypical cells. During surgical exploration, it was noted that the cyst extended to the level of the upper pole of the right kidney and opened into the bladder with an ectopic orifice superior to the right ureter, suggesting the presence of a blind-ending ureter. The normal ureter was dilated and compressed. During resection of the cystic mass, the right ureter was injured and ureteroneocystostomy was performed. Histopathologic identification of the cystic lesion was made as uroepithelial cells. No complication was seen in postoperative period.