Molar ectopic pregnancy in a cesarean scar treated with methotrexate - a case report and review of the literature.

Objective: To present a rare case of partial molar pregnancy implanted in a previous cesarean section scar and summarize the literature. Case report: A 33-year-old woman (gravida 5, two prior cesarean deliveries, two spontaneous abortions) presented with vaginal spotting and lower abdominal pain at 6 weeks of gestation. Transvaginal ultrasonography revealed a 28 × 19 mm gestational sac at the cesarean scar site, containing a 4mm fetus with positive cardiac activity. Vacuum curettage was performed under ultrasonographic guidance. Ten days postprocedure, rising serum beta-hCG levels and a persistent cystic mass on ultrasound raised suspicion for molar pregnancy. A single systemic dose of methotrexate was administered. Histopathology confirmed a partial molar pregnancy. The patient’s serum beta-hCG levels normalized within 8 weeks. Conclusion: Partial molar pregnancy in a cesarean section scar is an extremely rare condition that may present with vaginal bleeding and pelvic pain. Early recognition through ultrasonography and laboratory evaluation, combined with timely intervention including curettage and methotrexate therapy, can lead to complete resolution. Clinicians should consider this diagnosis in patients with previous cesarean sections to ensure optimal outcomes.