AFP and Pelizeaus-Merzbacher spectrum disorder: Placental mesenchymal dysplasia (PMD) is a rare benign disorder of the placenta characterized by placentomegaly and grapelike vesicles that can resemble at ultrasound examination with a molar pregnancy.[1] PMD was described initially by Moscoso et al[2] as stem villous hyperplasia with elevated maternal serum alpha-feto-protein and enlarged placentas with ultrasound features that are suggestive of partial mole.