Large Placental Chorioangioma In A Monochorionic Diamniotic Twin Pregnancy: A Case Report With Prenatal Ultrasound And Histopathological Correlation

Abstract

Background: Chorioangioma is the most common benign non-trophoblastic tumor of the placenta, typically asymptomatic and discovered incidentally. However, large or vascular chorioangiomas can lead to significant maternal and fetal complications. Twin pregnancies, particularly monochorionic diamniotic (MCDA), pose additional challenges due to shared placental circulation and increased baseline risk.

Case Presentation: We report a rare case of a 27-year-old woman second gravida with previous one abortion with a monochorionic diamniotic twin gestation, diagnosed at 27+6 weeks of gestation with a large vascular placental chorioangioma measuring 65 × 54 × 63 mm on routine anomaly scan. Color Doppler revealed prominent vascularity within the mass. One fetus exhibited a single umbilical artery and mild growth discordance. Serial ultrasonography was performed for close monitoring of fetal well-being and tumor progression. Histopathological examination post-delivery confirmed the diagnosis of chorioangioma, revealing proliferation of capillary-sized vessels within scant stroma and areas of infarction, fibrosis, and calcification.

Management and Outcome: The patient was managed conservatively with intensive antenatal surveillance. Despite the size and vascularity of the tumor, no evidence of polyhydramnios, fetal anemia, or hydrops fetalis was noted. Delivery was planned at term with multidisciplinary preparedness. Postpartum recovery was uneventful.

Conclusion: This case underscores the significance of early diagnosis and vigilant monitoring of large placental chorioangiomas in twin pregnancies. Conservative management with regular follow-up may result in favorable outcomes even in the presence of significant placental pathology.