Placental mesenchymal dysplasia with battledore insertion of the umbilical cord and retroplacental hematoma: a case report

Placental Mesenchymal Dysplasia (PMD) is a rare placental disorder characterized by a combination of placentomegaly, intraplacental vesicles, and dilated chorionic vessels. It may culminate in the delivery of a live newborn, unlike molar pregnancies. We report a case initially suspected as a partial molar pregnancy, with clinical signs of placental abruption posing a risk of preterm delivery. However, detailed anatomopathological examination confirmed PMD, macroscopically shows placentomegaly with cystic cavities, dilated and thrombosed chorionic vessels; histologically, it reveals enlarged, oedematous stem villi, ectatic vessels with thrombi, fibromuscular hyperplasia, and pseudocysts. This case was also associated with a marginal umbilical cord insertion, retroplacental hematoma, and inflammatory lesions, ultimately resulting in a favorable pregnancy outcome. Accurate diagnosis of PMD is crucial to differentiate it from molar pregnancies, as misdiagnosis can lead to unnecessary interventions. This case report underscores the importance of thorough placental examination, highlighting the association of PMD with various placental abnormalities and emphasizing the need for careful histopathological evaluation.