Stage | Observation |
---|---|
0 | Normal chest radiograph |
I | Bilateral hilar lymphadenopathy ± paratracheal lymphadenopathy. Despite no evidence of parenchymal infiltration, granulomas may be seen on lung biopsy |
II | Bilateral hilar lymphadenopathy plus lung parenchymal infiltration |
III | Pulmonary infiltration without hilar lymphadenopathy |
IV | Pulmonary fibrosis, with evidence of honey-combing, hilar retraction, bullae, cysts and emphysema |