Q J Med 2008; 101:503 doi:10.1093/qjmed/hcn040
Advance Access published on 28 March 2008
Clinical picture Cannabis as a cause of giant cystic lung disease A 55-year-old man presented with breathlessness on minimal exertion so severe that he was not able to walk across the room without having to stop to catch his breath. A chest X-ray suggested possible bullous formation, and this was confirmed by the high resolution CT of chest. The scans shown demonstrate a 11-cm. diameter cyst in the left lower lung and four in the right lung in the coronal section, and five on the transverse section. More than 40 bullae were identified. There was no relevant family history, and a serological test for alpha-1 antitrypsin was negative. The patient had smoked minimal tobacco (up to 5 packet years), but had consumed cannabis freely up to 7 g daily (equivalent to about 100 cones) for 25 years. This represents a maximum intake of 63 875 g over this period. No other relevant causes were identified. Cystic lung disease has been described in association with cannabis smoking for over 10 years.
There are likely several factors involved in its aetiology including the pattern of cannabis smoking (deep breaths and long periods of breath holding), and the fact that the tension on the cyst wall is related to the fourth power of the pressure in the cystic cavity (Laplace’s Law). Cannabis also causes airways inflammation both acutely and after chronic exposure. It is likely that this limitation of airflow particularly in expiration exacerbates tension in the cyst wall. Dental disease, bone loss and COPD suggest tissue proteinase activation, which in the lungs is likely to damage the delicate structure of the alveolar walls. Other recently described pulmonary complications of cannabis consumption include emphysema and lung cancer. Photograph and text from: A.S. Reece, Department of Medical School, University of Queensland, Brisbane, Queensland, Australia. email:
[email protected]
! The Author 2008. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email:
[email protected] 