Placental Mesenchymal Dysplasia: Ultrasound Characteristics and Diagnostic Pitfalls.

Placental mesenchymal dysplasia (PMD) is a rare, benign developmental anomaly with a reported prevalence of 0.02% (Arizawa and Nakayama, 2002). It is characterized by placentomegaly with multiple cystic lesions of the stem villi and vascular anomalies (Pawoo and Heller, 2014).