Two cases of ectopic ureter opening into the ejaculatory duct: double vas deferens revisited.

We report 2 rare cases of single ectopic ureter simulating double vas deferens. Clinical, radiographic and macroscopic signs at operation indicated a single ectopic ureter opening into the seminal tract. However, histological examination of the surgical specimen revealed that the lumen of the supposed ureter was lined in part by columnar epithelium, although chiefly by transitional epithelium. The wall of the ureter contained 3 well defined muscular coats in case 1 but only 1 layer was distinguishable in case 2. Histological composition of the structure removed from the cranial site resembled that of the epididymis. A review of the literature revealed a few comparable cases. Analysis of these cases suggests that double vas deferens and a single ectopic ureteral opening into the seminal tract are such that their differentiation may only have semantic significance. We speculate that these 2 diseases are included as 1 entity, only to be distinguished by the difference of ureterization of the ureteral bud.