Unintended consequences of vaginal misoprostol use in a patient with hydatidiform mole

Rationale: Hydatidiform mole (HM) is usually managed by suction curettage, while misoprostol is not recommended as a method of medical evacuation for molar pregnancy because of concerns regarding incomplete evacuation and postmolar gestational trophoblastic neoplasia. The use of misoprostol for cervical ripening before hysterectomy in patients with known molar pregnancy is also not supported by established evidence. This case highlights the potential risks of unintended misoprostol use in gynecologic procedures involving molar tissue. Patient concerns: A 49-year-old woman presented with vaginal bleeding and imaging findings suspicious for HM. Her serum β-human chorionic gonadotropin (β-hCG) level was markedly elevated at 589,830 mIU/mL. Diagnoses: Histopathological examination of the expelled molar tissue confirmed a partial HM. Although serum β-hCG initially declined markedly following complete expulsion, it subsequently increased at 9 to 10 weeks, indicating persistent or recurrent trophoblastic disease. Interventions: Hysterectomy was initially planned, and 400 μg of vaginal misoprostol was administered preoperatively for cervical ripening to facilitate uterine manipulator insertion. Unexpectedly, the patient experienced uterine contractions and complete expulsion of the molar tissue the following morning. Because of the subsequent rise in serum β-hCG, hysterectomy was performed. Persistent low-level β-hCG after surgery prompted methotrexate (MTX) treatment. Outcomes: Following MTX treatment, serum β-hCG levels plateaued, and the patient was considered to have MTX-resistant disease. Multi-agent chemotherapy with EMA-CO (etoposide, methotrexate, actinomycin D, cyclophosphamide, and vincristine) was subsequently administered. Lessons: This case illustrates the potential unintended consequences of using misoprostol in a patient with known molar pregnancy. Although complete expulsion of the molar tissue occurred, the subsequent development of postmolar gestational trophoblastic neoplasia and the need for multi-agent chemotherapy indicate that this should not be considered a favorable therapeutic outcome. Misoprostol should not be used for cervical ripening when hysterectomy is planned as the primary treatment for molar pregnancy. This case highlights the importance of avoiding inappropriate off-label use of misoprostol in the presence of molar tissue and emphasizes the need for careful post-evacuation β-hCG surveillance regardless of the initial clinical outcome.