Abstract
OBJECTIVES: Although placental chorangiomas are often asymptomatic, larger tumors (>4-5 cm) can cause various perinatal complications, including polyhydramnios, preterm birth, fetal anemia, fetal hydrops, and intrauterine fetal death. Symptomatic placental chorangiomas are often diagnosed prenatally on ultrasonography as a mass on the fetal side of the placenta. CASE PRESENTATION: A 37-year-old pregnant woman underwent emergency cesarean delivery at 34 weeks' gestation due to rapidly progressive fetal hydrops leading to fetal dysfunction, resulting in neonatal death. Placental pathology indicated multiple placental giant chorangiomas that occupied 40% of the placenta. Because of the disk shape of the placenta, prenatal diagnosis by ultrasonography was difficult. CONCLUSIONS: Some placental chorangiomas are difficult to diagnose and lead to fetal hydrops and poor prognosis, even if ultrasonography does not show an obvious mass in the placenta.