General ConsiderationsSalts of sali

General Considerations
Salts of salicic acid
90% of asbestos in the USA is white asbestos (chrysotile) occurs in automotive workers, shipfitters, construction workers
Asbestos particles invoke a hemorrhagic response in the lung
Fibers are then coated with a ferritin-like material resulting in ferruginous bodies
Produces its damage in respiratory bronchioles and alveoli
Affects lower lobes first
The presence of pulmonary parenchymal changes differentiates asbestosis from asbestos-related pleural disease
Imaging Findings
Opacities are small and irregularly shaped
Cardiac silhouette may become shaggy
All patients with asbestos-related pleural disease have, by definition, some pleural involvement
Pleural involvement without parenchymal disease is common
Pleural plaque
Parietal pleural plaques in the mid lung are the most common asbestos-related disorder and are usually bilateral
They occur most often in the 6th-9th interspaces usually sparing the apices and lung bases and involve the parietal pleura
Diffuse pleural thickening
Less common than pleural plaques
Diffuse pleural thickening involves diaphragmatic pleura, blunting of costophrenic sulci and lateral pleural thickening
Pleural calcification
Pleural calcification occurs in about 50% with asbestos-related disease, especially along the diaphragmatic pleura
Calcified pleural plaques seen en face have a characteristic rolled edge along their margins, denser than in the central portion of the plaque
The appearance of the entire plaque has been likened to a holly leaf
Later manifestation of pleural disease, calcification may occur in plaque or diffuse pleural thickening (less often)
Pleural effusion
Effusion alone may occur early in the disease (first 20 years) in about 3% of cases
Exudative, occasionally bloody, one-sided or bilateral
In contrast to silicosis, hilar lymph nodes are rarely affected
Associations with lung cancer and mesothelioma
Estimated to occur in 20-25% of those heavily exposed to asbestos
Asbestos-related lung cancer is usually either squamous cell or adenocarcinoma
Bronchogenic carcinoma is almost always associated with cigarette smoking
Increases risk of bronchogenic carcinoma up to 100x over that in non-smoking, non-asbestos exposed population
Mesotheliomas are not related to cigarette smoking
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