Müllerian duct remnant involving Wolffian system: a case report and literature review.

A 14-month-old boy with repeated left acute epididymitis was admitted to our department. Ultrasonography detected a midline round cystic mass in a retrovesical region. This was easily opacified by cystourethrography and seen to have a free communication with the posterior urethra. Since urethroscopy revealed a passable orifice in the center of the verumontanum, while a cystic-wall biopsy specimen showed squamous epithelium, we considered this cystic lesion to be an enlarged prostatic utricle. Vasography showed that the bilateral vasa was implanted directly into this cystic lesion, and was the possible cause of his left epididymitis. Ligature of the left vas deferens was performed to prevent left epididymitis. An enlarged prostatic utricle involving the vasa is a rare presentation.