Prenatal Diagnosis of Placental Mesenchymal Dysplasia and Its Association with Hepatic Mesenchymal Hamartoma in Beckwith-Wiedemann Syndrome: A Case Report.

Placental mesenchymal dysplasia (PMD) and hepatic mesenchymal hamartomas are rare diseases associated with Beckwith-Wiedemann Syndrome (BWS). We present the case of a 22-year-old diagnosed with PMD at 24 weeks gestation who required emergent delivery secondary to fetal distress and preeclampsia at 30 weeks' gestation. The neonate was diagnosed with a hepatic mesenchymal hamartoma following delivery. While genetic testing returned negative, a clinical diagnosis was made for BWS due to persistent hypoglycemic episodes, left lower extremity hyperplasia, an umbilical hernia, nephromegaly, bilateral ear creases, and periorbital creases. This case demonstrates that PMD may be the only prenatal indicator of BWS.