Antenatal detection of a communicating duodenal duplication

We report a case of a subhepatic cystic mass diagnosed in utero by antenatal ultrasonography (US) at 15 weeks' gestation which subsequently proved to be a communicating duodenal duplication. In this male foetus, the differential diagnosis was choledochal cyst, congenital biliary atresia, foregut duplication or omentum cyst. Neonatal US examination lead to a diagnosis of duodenal duplication, also confirmed by barium gastrointestinal series. He was operated on day 8 and recovered uneventfully. We discuss the accuracy of antenatal US in the diagnosis of such right upper quadrant cystic masses. Now that antenatal findings are becoming increasingly sensitive in the detection of foetal anomalies, and parents need to be informed about the suspected pathology and its prognosis, we tried to determine, in the light of this case and a review of the literature, how antenatal US findings can offer more accuracy in the diagnosis of duodenal duplication.