Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Tracheal amyloidosis
- Radiologic Findings
- Fig. 1. Chest radiograph showing diffuse narrowing of the trachea.
Figs. 2
- Brief Review
- Amyloidosis is a rare disorder of protein folding, and the amyloid deposits consist mainly of protein fibrils. The most important proteins are amyloid L and amyloid A. Amyloidosis affects the respiratory tract in approximately 50% of the cases. Amyloidosis can involve the lung parenchyma, trachea, bronchi, mediastinum, pleura, and heart. Histologic examination reveals amyloid deposits in subepithelial interstitial tissues, which show a characteristic apple-green birefringence when stained with Congo red and examined under polarizing microscopy.
Tracheobronchial amyloidosis typically manifests after the fifth decade of life, with dyspnea, cough, and occasionally hemoptysis or asthma-like symptoms.
Most of the patients show normal chest radiographic findings. However, focal or diffuse thickening of the airway with luminal narrowing can be seen. The findings of tracheobronchial amyloidosis on computed tomography include thickening of the airway wall with associated narrowing of the lumen and, in some cases, calcification foci. Wall thickening may be focal or diffuse and nodular, plaque-like, or circumferential. Tracheobronchial amyloidosis is generally confined to the trachea but can extend to the main, lobar, and segmental bronchi, and bronchial involvement is frequently associated with distal atelectasis, bronchiectasis, or air trapping. However, these imaging findings are nonspecific, and the differential diagnoses include a variety of diseases, such as relapsing polychondritis and tracheobronchopathia osteochondroplastica. Unlike these two disease entities, tracheobronchial amyloidosis can involve the noncartilaginous posterior wall.
- References
- 1. Christopher W, Janathan C. Mullers Imaging of the Chest 2nd edition: 538-542.
2. Czeyda-Pommersheim F, Hwang M, Chen SS, Strollo D, Fuhrman C, Bhalla S (2015) Amyloidosis: modern cross-sectional imaging. Radiographics 35:1381-1392.
- Keywords
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