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.