Spontaneous pneumomediastinum in a patient with recent air travel.

Spontaneous pneumomediastinum (SPM) is a fairly uncommon condition in which free air is present in the mediastinum, often in young patients without injury or serious underlying pulmonary disease. We present a case of SPM in a 36-year-old man with no pertinent medical history who presented with chest pain after a 3-h flight. To the best of our knowledge, this is the first known case in radiology literature of SPM caused by increased intra-alveolar pressure secondary to increased altitude.