Placenta, Mesenchymal dysplasia

Mesenchymal dysplasia is a rare placental abnormality in which the placenta is enlarged with vascular abnormalities. Such a placenta can sometimes raise concern for a molar pregnancy. The microscopic features show villi with severe hydropic changes, some with cisternae, along with stromal and vascular proliferation, interspersed with normal villi. Importantly, these changes are observed in the absence of trophoblastic proliferation, thus suggesting that this is unlikely to be associated with a partial molar pregnancy. Furthermore, array cytogenetics was consistent with a normal karyotype. Mesenchymal dysplasia may be a component of Beckwith-Wiedemann syndrome.