Case 246: MR Imaging of a Complex Cystic Mass in a Newborn Girl

Abstract
Female neonates can, and often do, have ovarian cysts, which may manifest as complex intra-abdominal masses. HistoryA 6-day-old female neonate presented to the outpatient pediatric surgery clinic for evaluation of a possible prenatal abdominal mass. The neonate was delivered at term via cesarean section due to macrosomia, with a reported birth weight of 11 lb 8.7 oz (5.23 kg). The patient’s postnatal course was remarkable for resolving neonatal hyperbilirubinemia. A physical examination was remarkable for a palpable mass in the abdomen. Maternal risk factors included class II obesity, type 2 diabetes, and metabolic syndrome.Prenatal images obtained at an outside institution were not available at this time. Ultrasonography (US) of the abdomen and pelvis was performed 6 days after birth. Follow-up US at 29 days of life revealed no substantial change in the appearance of the findings.This patient remained asymptomatic, and gadolinium-enhanced (Magnevist; Bayer Pharma, Berlin, Germany) magnetic resonance (MR) imaging of the abdomen and pelvis was performed at 84 days of life.The mass was excised surgically at 89 day...