Marijuana lung
Marijuana (cannabis or bong) lung refers to the presence of large apical bullae in patients who regularly smoke marijuana. A definite causative link between smoking marijuana and bullous lung disease has not been established, and the association may just be coincidental.
Pathology
Smoking marijuana has been demonstrated to cause chronic bronchitis, airflow obstruction, impaired large airway function and hyperinflation. There is a dose-response relationship to marijuana's effect on the lungs, with one marijuana joint equivalent to 2.5-5 cigarettes, possibly due to different inhalation techniques and lack of filters .
Macroscopic emphysema is rarely seen although large apical bullae in a paraseptal distribution have been described with secondary spontaneous pneumothorax as a complication . A definite causal link has yet to be established .