20 weeks pregnant woman for antenatal scan
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| 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
