Aberrant epididymal tissue: a significant clinical entity.

Epididymal anomalies are relatively rare and usually they are associated with an undescended testis. A 33 to 66 per cent incidence of epididymal anomalies has been noted in male subjects with cryptorchidism. An increased incidence of epididymal anomalies also has been noted in association with cystic fibrosis, von Hippel-Lindau's syndrome and in male offspring of women treated with diethylstilbestrol. The frequency and anatomical spectrum of epididymal anomalies among men with normal descended testes are not known. We describe 3 patients with bilaterally descended testes, who were found to have aberrant epididymal tissue at scrotal or inguinal exploration. The variable presentations of aberrant epididymal tissue in these 3 patients can be explained best by understanding the embryology and anatomy of the epididymis and its associated vestigial structures. In all likelihood the structures encountered in our patients were the ductus aberrans inferior and the paradidymis. These structures, which rarely are included in urological anatomical descriptions of the epididymis, can be significant clinically. Therefore, it is important that the urologist be aware of their existence and their means of presentation.