Definition:

Pneumothorax is defined as air or gas accumulated in the pleural space and can be classified as spontaneous or traumatic. Traumatic pneumothorax includes iatrogenic cases caused during procedures such as pacemaker insertion. Spontaneous pneumothorax can be subclassified as primary or secondary. Primary spontaneous pneumothorax (PSP), which is defined as a pneumothorax without underlying lung disease, predominantly occurs in young, thin males. It is usually caused by ruptured pleural blebs or bullae. Approximately 10% of patients with PSP have a positive family history. Gene mutations in folliculin (FLCN) have been found.