Partial hydatidiform mole with coexistent normal viable fetus: a rare case report

Introduction: Gestational Trophoblastic Disease (GTD) comprises a spectrum of placental abnormalities, with partial hydatidiform mole (PHM) representing a rare variant that can, in exceptional cases, coexist with a live fetus. Such cases present diagnostic and management challenges due to overlapping imaging features with other placental pathologies and potential maternal-fetal complications. Case Presentation: A 28-year-old pregnant woman was admitted at 34+1 weeks with severe preeclampsia and thrombocytopenia. After stabilization with magnesium sulfate, a cesarean section was performed due to failed induction. A macroscopically abnormal succenturiate lobe of the placenta with vesicular and cystic appearance was identified intraoperatively and sent for histopathology. Anatomopathological and immunohistochemical analysis confirmed the diagnosis of PHM, with villous edema, trophoblastic proliferation, and positive p57 staining in stromal and cytotrophoblastic cells. The newborn, phenotypically normal, had a favorable postnatal course. Conclusion: This report contributes to the scarce literature on PHM coexisting with a viable fetus, underscoring the importance of histopathological analysis of abnormal placental tissue and the need for clinical vigilance in pregnancies with unexpected placental findings and hypertensive disorders.