First report of a vaginal foreign body perforating into the retroperitoneum.

Pelvic examination of a 19-year-old woman with recurrent pain after multiple laparotomies revealed a 4.0 cm paracervical fibroepithelial polyp and tender fullness in the left pelvis. Abdominal exploration had normal findings, but exploration of the retroperitoneum revealed an encysted bottle cap that had eroded through the vaginal wall years before.