Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Tracheobronchial amyloidosis in a patient with RA
- Radiologic Findings
- On lung setting images of low dose chest CT, nodular lesions with irregular wall thickening are noted in the trachea, resulting in the narrowing of the airway. Those lesions spare the membranous portion of the trachea. Multiple bullae are noted in the upper lobes. On mediastinal setting images, those lesions contain calcifications. Diffuse airway narrowing with nodularity is also noted on virtual bronchoscopy. On bronchoscopy, whitish nodular lesions with diffuse luminal narrowing of trachea and bronchi were seen.
- Brief Review
- Amyloidosis is a disease characterized by extracellular deposition of insoluble fibrillar protein in various organs. Various forms of amyloidosis in the chest exist: nodular parenchymal amyloidosis, diffuse alveolar septal amyloidosis, airway amyloidosis, mediastinal amyloidosis, and cardiac amyloidosis. In primary amyloidosis, amyloid light chain (AL) is derived from the abnormal breakdown of immunoglobulin light chains. In secondary amyloidosis, the deposited protein is serum amyloid A (AA) , which is an acute-phase reactant noted in systemic infections and inflammatory disorders such as rheumatoid arthritis, chronic bronchitis, and osteomyelitis. Tracheobronchial amyloidosis occurs more often in a localized form. On CT, long segmental narrowing of the tracheobronchial lumen with wallthickening, nodules, or plaques are noted. Calcification or ossification of the involved airway is seen. Amyloidosis may involve the tracheal posterior membrane, unlike tracheobronchopathia osteochondroblastic or relapsing polychondritis, which spare the posterior membrane.
- References
- 1. Czeyda-Pommersheim F, Hwang M, Chen SS, Strollo D, Fuhrman C, Bhalla S. Amyloidosis: Modern Cross-sectional Imaging. Radiographics. 2015 Sep-Oct;35(5):1381-92.
2. Aylwin AC1, Gishen P, Copley SJ. Imaging appearance of thoracic amyloidosis. J Thorac Imaging. 2005 Feb;20(1):41-6
- Keywords
- Tracheobronchial amyloidosis, Airway amyloidosis,