Extragonadal mature cystic teratoma at anterior uterine wall coexisting with a pararectal corpus luteum cyst and agenesis of left fallopian tube and left ovary.

Objective: Mature cystic teratomas are mostly confined to the ovaries, but several authors have reported findings of extragonadal occurrences along the migration pathway of primordial germ cells. Extragonadal mature cystic teratomas are extremely rare; their occurrences and pathogenesis are unknown.

Case Report: We report the case of a 26-year-old woman who was admitted for scheduled laparoscopic right ovarian tumor excision. An anterior uterine wall mature cystic teratoma and a pararectal corpus luteum cyst were found intraoperatively with coexistence of left adnexal agenesis.

Conclusion: The existence of an extragonadal mature cystic teratoma over the anterior uterine serosal layer may be caused by autoamputation and reimplantation as a result of ovarian torsion or displacement of primordial germ cells along their migration path. The existence of an ovarian mass over the sigmoid colon combined with left adnexal agenesis may be the result of ovarian torsion with remnant tissue attached to the sigmoid colon.