Congenital lung malformations: a unified concept and a case report.

A left upper lobectomy in a 5-month-old infant revealed a specimen whose tissue, both grossly and microscopically, was characteristic of intr- and extrapulmonary swquestration, bronchial atresia, and adenomatoid cystic malformation. This case may be considered the missing link between the various congenital lung malformations, for it illustrates their interrelationship or their common origin. Atresia or malformation of the main bronchus seems to be the defect shared by all these anomalies. A similar bronchial abnormality probably is responsible for congenital lobar emphysema and isolated congenital lung cysts.