Discussion
Placental Chorioangioma is a non-trophoblastic tumor originating from primitive chorionic mesenchyme10. While the definitive cause of the condition remains elusive, various risk factors have been associated with its onset, including primiparity, maternal age exceeding 30, multiple pregnancies, maternal hypertension and diabetes, as well as carrying a female fetus 11,12. Our case aligned with these findings as it involved multiple pregnancies, high blood pressure, preeclampsia, and a female fetus.
Small-sized chorioangiomas are often incidentally discovered during the third trimester, whereas larger tumors (>4cm) are more easily identified 13. The diagnosis primarily relies on ultrasound, where they appear as well-defined lesions with distinct echogenicity compared to surrounding tissue 11,14,15. They are commonly found in close proximity to the cord insertion site on the fetal surface of the placenta, where they extend into the amniotic cavity16. Furthermore, color Doppler ultrasound is instrumental in distinguishing chorioangiomas from other placental lesions such as placental hematomas, chorangiocarcinoma, partial hydatidiform moles, teratomas, and degenerated fibroids10,17. Moreover, it can reveal the presence of a prominent feeding vessel within the tumor or confirm the vascular continuity between the tumor and fetal circulation18. Magnetic resonance imaging (MRI) commonly shows chorioangiomas as heterogeneous masses with iso-intensity to the placenta on T1-weighted images and hyper-intensity on T2-weighted images15,16. Additionally, MRI offers further anatomical information regarding the tumor’s extent and its connections with nearby structures, which can be beneficial in intervention planning19–21.
Placental chorioangiomas exhibit three histological subtypes. The capillary type is characterized by numerous capillary enlargements, the cellular type by dense parenchyma of immature cells with fewer angiogenesis, and the degenerative type by diverse degenerative changes, including fibrinoid necrosis and calcification. 16,22The vascularization of chorioangiomas is a prognostic factor affecting pregnancy outcomes. While non-vascularized chorioangiomas are generally uncomplicated, vascularized tumors can lead to various complications23. Polyhydramnios is the most common maternal complication, occurring in 18–35% of cases of giant chorioangiomas10. In addition, the primary fetal complications include hemolytic anemia, thrombocytopenia, non-immunologic hydrops, congenital anomalies, cardiomegaly, and congestive heart failure16. The pathophysiological mechanism underlying these complications arises from the presence of vascular channels within the tumor, which act as arteriovenous shunts. These shunts compromise the perfusion of chorionic villi, leading to reduced delivery of essential nutrients and oxygen to the fetal circulation. As a result, the fetal heart compensates to maintain tissue perfusion1,7,11. However, inadequate compensation may result in cardiac failure and hydrops fetalis, which often leads to adverse outcomes and fetal mortality 3, as observed in our case.
The management of pregnancy complications depends on both gestational age and maternal-fetal symptoms 14. A promising therapeutic approach for managing symptomatic cases involves blocking the tumor-feeding vessels. Various methods for achieving this objective include fetoscopy-assisted laser ablation or suture ligation, alcohol injection, microcoil embolization, and ultrasound-guided embolization3,24,25. The selection of the most appropriate vessel occlusion technique depends on factors such as the anatomical location or diameter of the target vessel and its proximity to the umbilical cord insertion site 2. Conservative management is feasible by closely monitoring the chorioangioma’s vascularity and growth as well as progressive fetal distress 15. Regular monitoring can extend gestation and prevent fatal complications through the timely use of intrauterine fetal transfusion and embolization of the supplying vessel 26,27. This highlights the potential for a positive fetal and maternal outcome with systematic follow-up.