Asynchronous pulmonary hyperplasia associated with tracheal atresia: pathologic and prenatal sonographic findings

We describe a case of pulmonary hyperplasia associated with tracheal atresia and a complete obstruction to the egress of pulmonary secretions. In classical pulmonary hyperplasia associated with cartilagenous laryngeal atresia and a persistent pharyngotracheal duct, the histologic appearance of the lungs is normal but exhibits "synchronous" hypermaturity. The histologic pattern in our case is much less mature, resembles CAM type III, and exhibits "asynchronous" development. We suggest that these histologic patterns be distinguished and that pulmonary hyperplasia is probably underrecognized and not nearly as rare as previously thought.