Abstract Introduction Cystic lung disease (CLD) refers to thin-walled, air-filled spaces within the lung parenchyma with diverse etiologies including lymphangioleiomyomatosis (LAM), pulmonary Langerhans cell histiocytosis (PLCH), and Birt-Hogg-Dubé (BHD) syndrome. Emerging data suggest a potential association between chronic cannabis use and cystic lung pathology, although evidence remains limited. We describe a case of newly diagnosed CLD in a patient with long-term heavy cannabis use and no identifiable alternative etiology. Case description A 71-year-old female with severe mitral regurgitation, HFpEF, COPD, hypertension, coronary artery disease, and polysubstance use presented with progressive dyspnea, nocturnal cough, and lower extremity edema. Initial imaging showed bilateral interstitial and alveolar opacities with small pleural effusions. She was treated for a congestive heart failure exacerbation but deteriorated, requiring ICU admission and mechanical ventilation. CT chest revealed centrilobular emphysema, bronchiectasis, diffuse ground-glass opacities, interlobular septal thickening, and evolving cystic changes. Autoimmune workup was negative, and vascular endothelial growth factor-D (VEGF-D) was normal (49 pg/mL), excluding LAM. Bronchoscopy demonstrated friable tissue with minimal bleeding; bronchoalveolar lavage was negative for infection. The patient improved with antibiotics, corticosteroids, and ventilatory support and was discharged after eight days with outpatient pulmonary follow-up. Discussion This case underscores a possible link between heavy cannabis use and cystic lung disease in the absence of known etiologies. The patient’s extensive use of high-potency cannabis (“moonrocks”) suggests a dose-related risk for parenchymal injury. Mechanistic hypotheses include chronic airway inflammation, alveolar destruction, and toxic effects of cannabis combustion byproducts. While previous reports describe giant cystic lung disease associated with cannabis, this case demonstrates a more diffuse cystic pattern with concurrent emphysematous and fibrotic features, expanding the spectrum of potential cannabis-related pulmonary injury. Conclusion Chronic cannabis inhalation may contribute to the development of diffuse cystic lung disease, even in patients without classic risk factors. As cannabis use becomes increasingly prevalent, clinicians should maintain vigilance for unexplained cystic lung changes and inquire about cannabis exposure during diagnostic evaluation. This abstract is funded by: None
Crisler et al. (Fri,) studied this question.