[Ectopia of vas deferens with opening into the ureter (author's transl)]

A 13 years old boy with a 2 year history recurrent rightsided epididymitis was found to have an ectopic orifice of the vas deferens opening into the distal part of the left ureter of a hypoplastic left kidney. Because of possible interference with fertility vasovesiculography was not done. Therefore it could not be identified whether the vas deferens was of right or left sided origin. The genesis of this extremely rare malformation is discussed.