Congenital cystic adenomatoid malformation of lung type 1.

Congenital cystic adenomatoid malformation, a rare developmental, hamartomatous abnormality of the lung, usually is unilateral, is localized, and presents in early infancy. Delayed occurrence in older children and multilobar involvement are rare. We describe a case of congenital cystic adenomatoid malformation type 1 with multilobar involvement, associated emphysema, and coexistent tracheobronchopathia osteochondroplastica in an adolescent girl for whom the correct diagnosis was achieved only on histologic examination. The importance of an accurate diagnosis of this entity enables proper subtyping, management to minimize the risk of infections and malignancy, and exclusion of associated malformations.