A Challenging Diagnosis: Placental Mesenchymal Dysplasia—Literature Review and Case Report

Abstract

We describe a 22-year-old woman (2-gravid) case who was referred to our clinic at 18 weeks of gestation for a placenta with vesicular lesions discovered on prenatal examination routine. An ultrasound exam at 31 weeks of gestation showed numerous vesicular lesions, which gradually augmented as the pregnancy advanced. A live normal-appearing fetus was confirmed by intrauterine growth restriction (IUGR). The maternal serum β-human chorionic gonadotropin level remained in normal ranges. At some point, a multidisciplinary medical consensus considered the termination of the pregnancy, but the patient refused to comply. At 33 weeks of gestation, preterm premature rupture of membranes (pPROM) occurred, and she spontaneously delivered a 1600 g healthy female baby with a good long-term outcome. Placental mesenchymal dysplasia (PMD) was retrospectively diagnosed after confronting the data from ultrasound, chorionic villus sampling (CVS), amniocentesis, pathological examination, and immunohistochemical stain. The lack of sufficient reports of PMD determines doctors to be cautious and reserved, approaching these cases more radically than necessary. We reviewed this disease and searched for all cases of PMD associated with healthy, live newborns.

Placental Mesenchymal Dysplasia: A Confusing Entity and the Definitive Role of Histopathology

“…Placental mesenchymal dysplasia is a rare placental disease in which chorionic vascular abnormalities constitute the hallmarks of that condition. On radiological and gross pathological evaluations, PMD is characterized by placentomegaly and placental cystic spaces, these features are similar to those present in PHM which is the most confusing entity with PMD 7 . The incidence of PMD is about 0.02% of all pregnancies 2 .…”

“…Authors explained the elevation of serum maternal AFP as the placental surface area is increased and accompanied by dilated blood vessels. So, excess AFP is passed from the fetal to maternal circulation 7 .…”

Placental mesenchymal disease masquerading as molar pregnancy with a favourable maternal and fetal outcome

“…There were 50 preterm deliveries (51.5%) with 49 growth-restricted babies (50.5%) and 15 IUFDs (15.4%). Two patients each had placenta previa and polyhydroamnios 8. In addition, six cases were associated with hepatic cysts, with five requiring postdelivery surgical resection and one resulting in stillbirth 9–14.…”

Displasia mesenquimal placentaria. A propósito de un caso

“…En la DMP, se ha demostrado una asociación con el sexo femenino de 3,6:1 y el crecimiento fetal restringido hasta un 50 % de los casos, lo que se confirma también en este caso (8). El crecimiento fetal restringido se encuentra asociado con hipoperfusión e hipoxia, por la presencia de las anomalías vasculares, trombosis e incluso con los corioangiomas (9). Histológicamente, estas placentas pueden distinguirse de las molas parciales a causa de la ausencia de proliferación trofoblástica, como se muestra en la Figura 5, al igual que la presencia de vellosidades con corioangiomas (7).…”