Presentation
Shortness of breath.
Patient Data
Few small patchy areas of interstitial thickening with mild bronchiolectatic changes in the bilateral upper lobes.
Extensive ground glass opacities and mosaic attenuation in the bilateral lung with intervening normal attenuation lung (Head cheese sign).
The main pulmonary artery is mildly dilated with a ratio of pulmonary trunk to ascending aorta ratio is more than 1.
No evidence of pulmonary thromboembolism.
Multiple discrete enhancing subcentimeter-sized mediastinal and bilateral hilar lymph nodes.
Case Discussion
The patient had a history of pigeon exposure and the findings of mosaic attenuation and probable air-trapping are compatible with hypersensitivity pneumonitis (HP). Reactive lymphadenopathy is a recognized feature of HP.
Pulmonary hypertension can complicate HP but is more common in chronic fibrotic disease. Pulmonary artery size is not a reliable indicator of raised pressure.
Co-author: Dr. Saket Sharma (DM, Pulmonology).