Ectopia of the vas deferens into the ureter. Case report and review of the literature.

Ectopia of the vas deferens into the ureter is a rare occurrence, frequently associated with anorectal anomalies. To date, 20 cases have been reported, accounting for a total of 26 vasoureteral communications, 6 of which are bilateral. Embryologically, ureteral ectopia of the vas deferens may be explained by an underlying defect in the proximal mesonephric duct or an abnormally cranial origin of the ureteric bud. We add the case of a newborn with an ectopic vas terminating into the ureter of a multicystic kidney.