Subchorionic vascular aneurysms of the placenta are rare lesions and may pr
esent confusion with chorioangioma or focal mesenchymal dysplasia on sonogr
aphy. To our Knowledge, the findings of placental aneurysms have not been r
eported in the ultrasound literature. We present a case with detailed sonog
raphic evaluation, including spectral and color Doppler and pathological an
alysis, that was mistaken for chorioangioma prenatally Knowledge of this be
nign entity may allow the sonologist to recommend conservative management i
n similar cases.