<unk>  limited to the respiratory tract is uncommon.<unk>  occurs in three histopathologic types
Focal deposits in the tracheobronchial tree
Diffuse parenchymal opacities
Single or multiple pulmonary nodules.
Nodular<unk>  is usually found incidentally on chest radiognaphs in asymptomatic, older adults.
The deposits originate in the muscular walls of small blood vessels, and as they enlarge, they spread into the interstitial tissues.
Focal deposits in the tracheobronchial tree
Diffuse parenchymal opacities
Single or multiple pulmonary nodules.
Pulmonary amyloidosis
Sarcoidosis
Lymphomatoid granulomatosis
Hypertrophic pulmonary osteoarthropathy
Idiopathic interstitial pneumonia
Bronchocentric granulomatosis
Tuberculosis
Idiopathic pulmonary fibrosis