DOI: https://doi.org/10.36347/sjmcr.2026.v14i05.081

Pages: 1203-1205

Hypersensitivity pneumonitis is an immune-mediated interstitial lung disease caused by repeated inhalation of environmental antigens, most frequently avian proteins in bird fancier’s lung. Spontaneous pneumomediastinum is a rare presenting manifestation and may delay diagnosis. We report the case of a 37-year-old woman presenting with extensive pneumomediastinum associated with diffuse bilateral micronodules on chest CT, leading to the diagnosis of hypersensitivity pneumonitis secondary to chronic avian exposure. This case highlights the importance of recognizing atypical radiological presentations of hypersensitivity pneumonitis and emphasizes the key role of CT imaging in identifying both mediastinal air leakage and the underlying interstitial lung disease pattern.