CHORIOANGIOMA

20 weeks pregnant woman for antenatal scan



Sonography of placenta: A well defined oval hypoechoic lesion arising from fetal surface of placenta with significant internal vascularity on doppler. No evidence of calcifications.

·        Chorioangiomas are the most common non trophoblastic tumors, occurring  in less than 1% of pregnancies.

·        Chorioangiomas are essentially hemangiomas of the fetal portion of the placenta, supplied by the fetal circulation.

·        Vast majority are small and of no clinical signifi cance.

·        Large (>5 cm) or multiple lesions (so-called chorioangiomatosis) stress the fetal circulation and can be associated with complications such as hydrops, thrombocytopenia, intrauterine growth retardation, and an overall increase in antepartum mortality.

·        Given that the vast majority of chorioangiomas are incidentally identified, the sonographic characteristics are best described.

·        well-circumscribed, rounded, hypoechoic  or mixed-echogenicity masses protruding from the fetal side of the placenta.

·        Most are located near the cord insertion, and Doppler imaging reveals substantial vascularity or a large feeding vessel.

·        MRI is used only as an adjunct for further evaluation in equivocal cases.

·        Chorioangiomas are isointense on T1-weighted images with increased signal intensity on T2-weighted images.

·        Focal areas of increased signal intensity on T1- and T2-weighted images correspond to intralesion hemorrhage.

·        Placental teratomas are extremely rare and are similar in appearance to chorioangiomas, but are differentiated by the presence of calcifications.

Reference : Imaging of the Placenta: A Multimodality Pictorial Review1 ©RSNA, 2009