Involvement of the trachea is rare, and when it occurs, it is associated with laryngeal involvement. The proximal and distal parts of the trachea may be affected and the appearance of the stenosis may be smooth, irregular and nodular, or even mass-like. Bronchial involvement is much more common as a manifestation of sarcoidosis. 

The commonest signs at CT are regular or nodular bronchial wall thickening reflecting the presence of granulomas and fibrous tissue in the peribronchial interstitium. This bronchial wall thickening may result in smooth or irregular bronchial narrowing, which correlates with the presence of mucosal thickening at bronchoscopy and presumably reflects prominent inflammation in this location. Obstruction of lobar or segmental bronchi may occur as a result of airway wall fibrosis, compression by granuloma or peribronchial lymph nodes, of conglomerate fibrosis or some combination of these phenomena. Bronchial stenosis may clear spontaneously or with steroid treatment.

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