Abstract
Placental mesenchymal dysplasia is a rare condition of the placenta and its true incidence and underlying cause has remained unknown till now due to its rarity. Its accurate diagnosis is essential, because placental mesenchymal dysplasia is usually compatible with a good fetal and maternal outcome. A precise ultrasonographic evaluation can contribute to the identification of characteristic features, particularly to discriminate it from partial hydatidiform mole, its main differential diagnosis. We report an early third-trimester pathologically- diagnosed case of placental mesenchymal dysplasia. It was complicated by fetal hydrops and death.