Spontaneous pneumomediastinum and subcutaneous emphysema.

: Spontaneous pneumomediastinum with subcutaneous emphysema is a well-documented phenomenon which usually follows a benign course and rarely results in circulatory collapse and death. The condition is caused by a sustained increase in the intra-alveolar and intrabronchial pressure with air dissecting along the perivascular spaces of the mediastinum. The majority of patients respond to conservative therapy and rarely require aggressive surgical intervention. Three cases are presented. The anatomy, etiology and the pathophysiology of the disease are reviewed, and the treatment options discussed.