Primary spontaneous pneumothorax: a diffuse disease of the pleura.

Primary spontaneous pneumothorax (PSP) is by definition not associated with any underlying lung disease. However, this does not mean that there is no underlying pathological process. It has become increasingly apparent over recent years that PSP is associated with diffuse and often bilateral abnormalities within the pleura and is not simply a disease caused by ruptured blebs/bullae. The pathological process includes emphysema-like changes, pleural porosity and inflammation. In this review, we summarise the recent advances in our understanding of the pathogenesis of PSP and discuss how this relates to management strategies for patients with PSP.