Congenital Cystic Adenomatoid Malformation

Abstract

Congenital cystic adenomatoid malformation (CCAM) is a rare developmental abnormality of the lung. CCAM is considered as a hamartomatous abnormality of the lung (abnormal tissue with an excess of one or more tissue components), which results from adenomatoid proliferation of the terminal bronchioles resulting in the formation of cysts with a consequent reduction in alveolar growth. CCAM represents approximately 25 % of all congenital lung malformations. CCAM generally communicates with the bronchial tree and derives its blood supply from the pulmonary circulation, in contrast to pulmonary sequestration, which derives its blood supply from the aorta. Polyhydramnios has also been associated with CCAM. This develops as a result of elevated intrathoracic pressure that leads to esophageal compression and inability to swallow. With the increasing use of prenatal ultrasonography as well as improvement in technology and skill, most cases of CCAMs are prenatally diagnosed. CCAMs are typically identified prenatally by routine ultrasonography screening. CCAM may present in the older child and adults as an incidental finding or discovered secondary to repeated chest infections.