Spontaneous Pneumothorax Secondary to Bullous Lung Emphysema Positive for Cannabinoids upon Toxicological Examination.

Cannabis can be related to respiratory diseases, but the relationship between smoking marijuana and the development of a pneumothorax has scarcely been investigated. We aimed to analyze, in patients with a history of cannabis smoking abuse submitted to lung apicectomy for a primary spontaneous pneumothorax (PSP), the correlation between the presence of cannabinoids in the resected lung and the detection of bullous emphysema within the same tissue. Patients undergoing lung apicectomy for a PSP were prospectively enrolled, and the correlation between the presence of cannabinoids in the resected lung tissue and histological finding of bullous emphysema was investigated with Fisher's exact test. There were 21 male patients, with a median age of 27 years. The cannabinoids found by the toxicological examination in surgical specimens were mainly delta-9-tetrahydrocannabinol (THC), cannabinol (CBN), and cannabidiol (CBD). In 14/21 patients, cannabinoids were detected in the resected lung tissue, and bullous emphysema was present in 13/14 of these (93%), while bullous emphysema was found in only 1/7 (14%) of the remaining patients who were negative for cannabinoids in the lung tissue, and the difference was found to be statistically significant (p < 0.0009). Our study demonstrated the presence of bullous emphysema in most cannabinoid-positive patients and its absence in most of those who were cannabinoid-negative, supporting the correlation between cannabinoids in the lung tissue and bullous emphysema with the development of a "secondary" spontaneous pneumothorax.

Cannabinoids Identification in Lung Tissues of Young Cannabis Smokers Operated for Primary Spontaneous Pneumothorax and Correlation with Pathologic Findings.

BACKGROUND: Several studies suggested the association between tobacco and cannabis smoking and the risk of primary spontaneous pneumothorax (PSP), but none demonstrated cannabinoids in human lung tissues. OBJECTIVES: The aim of this study was to identify cannabinoids in lung specimens of young cannabis smokers, operated for PSP, and investigate on their pathologic findings, to determine the role of cannabis in PSP pathogenesis. METHOD: A prospective, multicenter study was conducted, enrolling patients admitted for PSP. Inclusion criteria were PSP requiring surgical treatment and history of cannabis smoking, associated or not to tobacco. Control cases were nonsmokers, and tobacco only smokers operated for PSP. Lung apex wedge resection by video-assisted thoracic surgery was performed. Two lung specimens, for pathological and toxicological examination, were taken from each patient. RESULTS: Twenty-nine male patients were enrolled: 21 (72.4%) tobacco and cannabis smokers, 2 (7%) cannabis only smokers, 3 (10.3%) tobacco only smokers, 3 (10.3%) nonsmokers; all underwent lung apicectomy, 4 bilateral surgery, for a total of 33 procedures. Typical PSP pathologic findings were mainly detected in control cases, other alterations in cannabis users. Lung specimens resulted positive for cannabinoids on 22/33 cases (19/22 reported being, 3/22 not being cannabis smokers), negative on 11/33 (3/11 reported not being, 7/11 having been cannabis smokers, 1/11 cannabis smoker). CONCLUSIONS: Our study demonstrated the presence of cannabinoids and particular pathologic alterations in lung tissues of young cannabis smokers with PSP, supporting the correlation between this disease and marijuana abuse and suggesting spontaneous pneumothorax "secondary to marijuana" as a new nosological entity.