Two cases of double ureter experienced upon body dissection in the Kumamoto University Medical School were reported:
1) Case 1: In a female cadaver, the renal pelvis was duplicated in the left kidney with associated complete ureteral duplication which continued into the bladder base with independent ureteral openings. Since the two ureters cross in the lower part, the original positional relationship between these two ureters was reversed at the opening site.
2) Case 2: In a 77 year-old female cadaver, bilateral double renal pelves were noted. The ureters which continued from the pelves also doubled only at a higher level (incomplete double ureter). In this case, obstruction of the left ureter was noted close to the opening at the bladder, probably due to infiltration of the carcinoma tissue. Marked hydronephrosis was noted in the kidney on the same side.
3) An embryological discussion was presented on the normal development of the ureter and the appearance of a double ureter.