Mesenchymal hamartoma of the liver: a benign tumor with deceptive prognosis in the perinatal period. Case report and review of the literature.

This article reports a case of perinatal mesenchymal hepatic hamartoma and reviews the literature on the subject. A fetus presented with polyhydramnios and a large multiloculated cystic abdominal mass at 33 weeks of gestation. The ultrasound appearance was most consistent with a mesenteric cyst. Prenatal drainage was considered, due to the size of the lesion. However, a conservative management was opted for. A female infant was born at 35 weeks by classical cesarean section. The immediate postnatal period was characterized by hemodynamic instability. Laparotomy revealed a pedunculated mesenchymal hamartoma of the liver, which could not completely be resected. The infant had an uneventful postoperative recovery and is doing well at 6 months of age. Hepatic mesenchymal hamartoma are rare benign tumors. Most cases are detected in early childhood. They usually present as a cystic rapidly growing abdominal mass. Prenatal diagnosis remains challenging. In children diagnosed in the perinatal period, the outcome seems worse and determined by the compressive effect of the mass.