Focal aneurysmal dilatation of subchorionic vessels simulating chorioangioma

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.