[Intrapulmonary laceration revealed by computed tomography in a patient with pneumomediastinum].

An 18-year-old man had bronchial asthma and a pneumomediastinum. A computed tomographic scan of the chest revealed the pneumomediastinum, intrapulmonary laceration of the S1b, and a small amount of air in the perivascular space from V1a to V1. Increased pressure in intrapulmonary airways may have resulted in ruptured S1b alveoli and air leakage into the interstitium between the surrounding secondary lobules. The air may have moved along the perivascular space (pulmonary vein) toward the hilum, and eventually into the mediastinum. We know of no previous report of pneumomediastinum in which images of intrapulmonary lesions are presented. In this case computed tomography revealed the mechanism by which the pneumomediastinum probably developed.