Cytologic features of vaping-induced lung injury: A case report.

Vaping-induced lung injury is a recently recognized phenomenon owing to the rising popularity of e-cigarette use. A cluster of cases of varying severity, including six deaths, was recently reported in the United States by the Centers for Disease Control. The objective of this report is to highlight the cytologic features suggestive of vaping-induced lung injury. A 20-year-old previously healthy man presented with a 7-day history of progressively worsening respiratory symptoms including dyspnea on exertion, cough, and fever, with no improvement after initiating a course of antibiotics. No relevant travel or occupational history was reported, but patient endorsed daily use of e-cigarette with a fluid containing both tetrahydrocannabinol and nicotine. Radiographic studies demonstrated scattered areas of interlobular septal thickening and diffuse ground-glass opacities in both lungs. Laboratory tests for HIV and influenza were negative. Bronchoscopy and bronchoalveolar lavage were performed, with cytologic study showing clusters of benign bronchial cells and an increase in lipid-laden macrophages by Oil Red O stain. Patient was placed on steroid and steadily improved for the next 2 days. He was discharged on a steroid taper and follow-up with respiratory clinic. Case reports and series have shown a variety of lung injury patterns in previously healthy patients who are frequent users of e-cigarettes and among them features suggestive of lipoid pneumonia with increased lipid-laden macrophages. The clinical utility of this finding is still unclear.