Abstract
An industrial explosion released nitrogen oxide, which a 43-year-old man inhaled at work. He developed cough and exertional dyspnea without hypoxemia, and chest computed tomography obtained two days after exposure showed poorly defined centrilobular ground-glass nodules predominantly in the lingular and lower lobes. Bronchoalveolar lavage revealed an increased total cell count with mild lymphocytosis. Transbronchial lung biopsy demonstrated type II pneumocyte hyperplasia, mural thickening with focal fibrosis, and fibrin deposition consistent with centri-acinar dominant alveolitis. Supportive care without corticosteroids led to clinical and radiologic resolution. This case highlights the latent onset pattern after nitrogen oxide inhalation and provides clinicoradiologic-pathologic correlation for a mild presentation, suggesting that careful observation may be reasonable when oxygenation is preserved and no progression is observed.