Antenatal diagnosis of abdominothoracic alimentary tract duplication: a case report.

Alimentary tract duplications are rare, linked in their tubular form with a disturbance of organogenesis at the time of the separation of the notochord during the 4th week of gestation. Its division leads to the formation of a supernumerary esophagus, situated in the posterior mediastinum, associated with vertebral malformations and connected at its distal extremity with the alimentary tract. We report a case of esophageal duplication revealed antenatally as an ultrasound image of fluid tonality in the posterior mediastinum, causing a major pleural effusion. The other diagnostic possibilities are discussed in terms of the anatomy, embryogenesis and ultrasonographic appearance of the lesion.