Incidental bilateral ovarian dermoid cysts discovered at cesarean section after an uncomplicated pregnancy: a case report highlighting antenatal diagnostic limitations

Abstract

Adnexal masses are detected in approximately 1.5–3% of pregnancies, the majority being benign. Dermoid cysts (mature cystic teratomas) are the most common benign ovarian tumors and are rarely large or bilateral in pregnancy. We report a rare case of incidentally detected bilateral ovarian dermoid cysts at term during cesarean section. A 31-year-old primigravida at 37+5 weeks of gestation underwent lower segment cesarean section for failed induction of labor with prelabor rupture of membranes. Antenatal ultrasonography showed no adnexal abnormalities. Intraoperatively, bilateral ovarian cysts were discovered: an 6 × 7 cm right ovarian cyst with complete ovarian involvement and a 4 × 3 cm left ovarian cyst. Right oophorectomy and left ovarian cystectomy were performed. Histopathology confirmed mature cystic teratomas with no malignant features. The postoperative course was uneventful. This case highlights the diagnostic limitations of late-pregnancy ultrasonography due to its largely asymptomatic nature both clinically and radiologically and supports removal of incidental adnexal masses during cesarean section to prevent future complications and reoperation.