Prenatal diagnosis of duplication cyst of the pylorus.

The first description of the antenatal appearance of a duplication cyst of the pylorus is presented. Prior to the infant's delivery, the possibility that this intra-abdominal cystic mass represented a choledochal cyst was also strongly considered. The antenatal detection of this cystic mass allowed close neonatal surveillance and timely surgical intervention prior to the onset of serious neonatal complications. The embryogenesis of duplication cysts of the gastrointestinal tract and bronchopulmonary foregut malformations is reviewed. The clinical utility of the prenatal diagnosis of such fetal gastrointestinal anomalies is also discussed.