Amyloidosis: Modern Cross-sectional Imaging

Abstract

Amyloidosis is a rare diverse condition caused by the pathologic extracellular deposition of abnormal insoluble proteins throughout the body. It may exist as a primary disease or, more commonly, may be secondary to a wide variety of pathologic processes ranging from chronic infection or inflammation to malignancy. Hereditary forms also exist. On the basis of the structure of the protein deposits, more than two dozen subtypes of amyloidosis have been described. A single organ or multiple organ systems may be affected. The radiologic manifestations of amyloidosis are varied and often nonspecific, making amyloidosis a diagnostic challenge for the radiologist. In the chest, the lungs, mediastinum, pleura, and heart may be involved. Lung involvement may manifest as diffuse reticulonodular interstitial thickening, consolidations, or solitary or multiple parenchymal nodules that may calcify, cavitate, and slowly enlarge. Pleural involvement most commonly manifests as pleural effusions. Tracheobronchial involvement may exhibit concentric airway thickening, mural and intraluminal nodules, submucosal calcification, and airway obstruction. Mediastinal and hilar lymph nodes may enlarge and frequently calcify. At cardiac magnetic resonance (MR) imaging, the left ventricular wall is typically thickened, with associated diastolic dysfunction. Delayed contrast material-enhanced cardiac MR imaging typically shows global transmural or subendocardial enhancement. The pathophysiology, classification, treatment, and prognosis of amyloidosis are reviewed, followed by case examples of the appearance of thoracic and cardiac amyloidosis on chest radiographs, computed tomographic (CT) images, and cardiac MR images.

Primary Laryngo-Tracheobronchial Amyloidosis: A Case Report and Literature Review

“…Amyloidosis occurring in the respiratory system may involve the larynx, trachea, bronchus, lung, and mediastinal lymph nodes. Respiratory tract amyloidosis may occur in cases of systemic amyloidosis, but more often occurs in isolation [5]. Primary laryngo-tracheobronchial amyloidosis is a rare pulmonary disease; laryngeal amyloidosis accounts for benign laryngeal tumors in approximately 0.2% to 1.2% of cases [6].…”

Middle lobe syndrome: an intriguing presentation of tracheobronchial amyloidosis

“…CT features are suggestive of nodules, endoluminal irregularities, circumferential thickening of the airways and tracheal stenosis and calcification 14 15. In addition, parenchymal abnormalities such as bronchiectasis and lobar collapse may be evident especially in distal disease 15. HRCT helps in defining the extent and degree of luminal narrowing and planning therapy 14.…”

The Lung in Dysregulated States of Humoral Immunity

“…Sometimes, a diffuse micronodular pattern may be observed [141,182,183]. Areas of septal thickening, predominantly peripheral and basal consolidation, patchy GGO and parenchymal micronodules are all compatible with interstitial amyloidosis [184] (Fig. 5).…”