Crossed ectopic testis with common vas deferens.

Crossed ectopic testis is an uncommon anomaly. A 10-month-old boy with a crossed ectopic testis and a common vas deferens is presented. At operation 2 testes were in the left inguinal canal. The seminal vesiculogram showed that both vasa deferentia fused to form a common lumen, and then formed a common stem on the left side and opened into the posterior urethra. The spermatic arteriogram revealed that each testis was supplied from the right and left sides, respectively. No testis or vas deferens was located in the right retroperitoneal space. These features suggested that the testes developed from both sides and subsequently descended to the left side.