A Rare Case of Biparental Placental Mesenchymal Dysplasia: A Case Report and Literature Review [ID: 1336615]

INTRODUCTION: Placental mesenchymal dysplasia (PMD) is a rare placental anomaly associated with high perinatal mortality; it is predominantly seen in female fetuses and very few cases have been reported. The evaluation of first- and second-trimester products of conception is of the utmost importance when assessing molar pathologies such as complete hydatidiform moles, partial hydatidiform moles, and nonmolar samples. METHODS: We report a monochorionic 46XX,69XXY pregnancy with placental mesenchymal dysplasia (PMD) with possible androgenetic biparental mosaicism etiology (Instituto Nacional de Perinatología Isidro Espinosa de los Reyes approval number P-270-18). RESULTS: The patient is a 28-year-old gravida 2, para 1, female with no notable past medical history. She had a previous pregnancy resulting in an uncomplicated abdominal delivery at 39 weeks of gestation 5 years prior. The patient was transferred to our health center at 24.2 weeks of gestation with a molar component because of USG data consistent with a probable hepatic tumor, perimembranous ventricular septal defect, and probable PMD. Ultrasound at 24.3 weeks of gestation demonstrated a single intrauterine pregnancy with one-third of the placenta appearing normal, the second third showing irregular cystic masses, and the remaining third with larger cysts. Placental mesenchymal dysplasia was diagnosed retrospectively based on data from the gross, histologic, and genetic components. CONCLUSION: To our knowledge, this is the first reported case of PMD with a 46XX,69XXY karyotype. A radical and cautious approach to PMD cases is needed because of the lack of sufficient data and reports.