Respiratory manifestations in amyloidosis

Amyloidosis is a collection of diseases in which different proteins are deposited. Amyloid deposits occur in systemic and organ-limited forms. In both systemic and localized forms of the disease, lung can be involved. The aim of this study was to explore the different respiratory manifestations of amyloidosis.

Chest radiology, clinical presentations, bronchoscopic/laryngoscopic findings and lung function data of 59 patients with amyloidosis involving respiratory tract collected during January 1986 to March 2005, were analysed.

Of the 16 cases with localized respiratory tract amyloidosis, 8 had the lesions in the trachea and the bronchi, 2 in the larynx and the trachea, 5 in the larynx and/or the pharynx, and 1 in the lung parenchyma. Of 43 systemic amyloidosis with respiratory tract involvement, 3 had the lesions in bronchi, 13 in lung parenchyma, 33 in pleura, 8 in mediastina, 1 in nose and 1 in pharynx. Chest X-rays were normal in most cases of tracheobronchial amyloidosis. CT, unlike chest X-rays, showed irregular luminal narrowing, airway wall thickening with calcifications and soft tissue shadows in airway lumen. Localized lung parenchymal amyloidosis presented as multiple nodules. Multiple nodular opacities, patch shadows and reticular opacities were the main radiological findings in systemic amyloidosis with lung parenchymal involvement. In pleural amyloidosis, pleural effusions and pleural thickening were detected. Mediastinal and/or hilar adenopathy were also a form of lung involvement in systemic amyloidosis. The major bronchoscopic findings of tracheobronchial amyloidosis were narrowing of airway lumen, while nodular, 'tumour like' or 'bubble like' masses, with missing or vague cartilaginous rings, were detected in about half of the patients.

Localized respiratory tract amyloidosis mostly affects the trachea and the bronchi. Chest X-rays are not sensitive to detect these lesions. Systemic amyloidosis often involves lung parenchyma and the pleura. Open lung biopsy or pleural biopsy should be performed for the diagnosis.