In-flight spontaneous pneumothorax: congenital cystic adenomatoid malformation of the lung.

Congenital cystic adenomatoid malformation (CCAM) is a rare congenital abnormality. Symptomatic presentation in adult life is extremely uncommon. The usual radiological appearance of CCAM is a cystic space-occupying lesion. Patients with underlying cystic lung disease can develop in-flight complications because of pressure-volume changes during ascent. We report the first ever case in which spontaneous pneumothorax during flight was the presenting manifestation of CCAM of the lung in a previously healthy and asymptomatic young adult. We also discuss the physiological changes during air travel which contribute to the pathogenesis of respiratory complications during air travel.