Mesenchymal stem villous hyperplasia of the placenta and fetal growth restriction.

BACKGROUND: Mesenchymal stem villous hyperplasia of the placenta is a rare placental anomaly characterized by placental vascular malformation and the appearance of a partial mole. CASE: A multiparous woman presented with fetal growth restriction (FGR) at 35 weeks' gestation. Ultrasonographic examination showed multiple anechoic lesions on the placental surface. Cesarean delivery was performed at 37 weeks' gestation, and a healthy 1536-g female was delivered. The placenta had aneurysmal dilatations of the chorionic vessels. Unlike other cases, it also showed subamniotic hemorrhage and had no features of a partial mole. Histologic examination established the diagnosis of mesenchymal stem villous hyperplasia of the placenta with severe thrombosis.
CONCLUSION: Fetal growth restriction can be caused by severe thrombosis in this placental anomaly.