Upon surgical exploration, a ruptured mature cystic ovarian teratoma was confirmed to be the diagnosis.

Rupture is an uncommon, but known complication of mature cystic ovarian teratoma. On CT, the best clue is fat density within the peritoneal spaces and can be quite subtle. In this case, an abnormal appearing appendix, mimicking equivocal acute appendicitis was also present, but confirmed to be normal surgically.