Abstract
Introduction:
The presence of free air within the mediastinum, that is not associated with trauma, is known as spontaneous pneumomediastinum [1].
The disease was originally described by Rene Laennec in 1819. The word spontaneous was introduced by Hamman later in 1939.The condition can result from an injury that leads to air leakage into the mediastinum from the lung . Spontaneous indicates that it is encountered in patients with underlying lung diseases or without any medically relevant conditions as compared to that secondary pneumothorax that results from trauma [2]. The pathophysiological mechanisms underlying pneumomediastinum are six:
1) Direct mechanism
2) Hamman-Macklin mechanism
3) Subfascial route (secondary to pneumothorax or chest wall injury)
4) Subserosal route: