In the name of GOD

Asbestos-Related Disease

Asbestos Exposure General Salts of salicic acid 90% of asbestos in USA is white asbestos (chrysotile) Occurs in : Automotive workers-brake linings Shipfitters Construction workers

Asbestos-Related Disease Types of Fibers Chrysotile (white asbestos)–benign Crocidolite (blue/black asbestos) in South Africa/Australia–malignant Crocidolite-small fibers-associated with most pleural disease

Asbestos-Related Disease Types of Fibers: Serpentins Chrysotil (white asbestos) Amphibole Crocidolith (blue) Amozith (brown) Anthophylith Tremolith

Asbestos particles invoke a hemorrhagic response in lung Asbestos-Related Disease Pathophysiology Asbestos particles invoke a hemorrhagic response in lung Fibers then coated with a ferritin-like material resulting in ferruginous bodies Damage to respiratory bronchioles and alveoli

Asbestos-Related Disease Types of Asbestos-related Pleural Disease Asbestosis Asbestos-related Malignancies

Asbestosis (pulmonary parenchymal fibrosis) 1- Almost always involves lower lobes at subpleural areas 2-As the disease progresses, fibrosis and volume loss ensue 3-Honey-combing in lower lobe subpleural areas 4-Tracheobronchial nodal involvement is unusual 5-PMF is very uncommon

Asbestos-Related Pleural Disease Pleural plaques Diffuse pleural thickening Pleural calcification Pleural Effusion

Asbestos-Related Pleural Disease Incidence of Pleural Disease Almost all have some pleural involvement Pleural plaque 65% Diffuse pleural thickening 17% Calcification 50% Effusion 21% Pleural involvement without parenchymal disease is common

Asbestos-Related Pleural Disease Pleural Plaques-1 Affects submesothelial layer of parietal pleura Bilateral, mid-lung zone Between 7th and 10th ribs Diaphragmatic pleura Spares apices

Asbestos-Related Pleural Disease Pleural Plaques-2 Plaques don’t usually calcify Plaques alone are not associated with malignancy Appear either in “profile” or “en face”

Asbestos-Related Pleural Disease Diffuse Pleural Thickening-1 Diffuse thickening of parietal pleura Involves diaphragmatic pleura, extends up lateral chest wall Commonly obliterates costophrenic angles Spares apices of lungs DDX from TB

Asbestos-Related Pleural Disease Diffuse Pleural Thickening-2 Frequently the sequela of benign pleural effusion Associated with rounded atelectasis

Rounded Atelectasis Part of peripheral parenchyma invaginated into the penetrating fibrotic visceral pleura, so that part of the parenchyma is entrapped and becomes atelectatic

HRCT findings of Rounded Atelectasis 1-Continuing with areas of diffuse pleural thickening 2-Lenticular or wedge-shaped 3-Comet-tail sign 4-evidence of volume loss in the affected lobe often associated with hyperlucency of the adjuscent lobe

Asbestos-Related Pleural Disease Pleural Effusion Effusion alone may occur early in disease (first 15 years) in about 3% of cases Exudative May be associated with chest pain Involves visceral pleura as well Does not mean mesothelioma May be associated with rounded atelectasis

Diagnostic Criteria: 1-Exposure history for asbestos 2- Ruling out other causes 3-Failing to detect tumor in a 3 years follow-up

Pathological description: Chronic fibrinous pleuritis with low cellularity Prognosis: Good with a self-limited course Recurrence may occur

Asbestosis General Reserved for parenchymal lung disease Fibrosis begins around bronchi and progresses outward

Asbestosis Interstitial lung disease Rounded atelectasis

Asbestosis Location More common in lower lungs More common subpleural

Asbestosis X-ray Opacities are small and irregularly shaped Not rounded as in silicosis Prominent septal lines around 2° lobules Cardiac silhouette may become shaggy Hilar lymph nodes rarely affected DDx from silicosis

Asbestosis HRCT Multiple subpleural dot-like nodularities=subpleural lines Fibrous bands Subpleural pulmonary arcades Honeycombing Thickened interlobular lines Ground-glass appearance

Asbestos-Related Malignancies Bronchogenic carcinoma Mesothelioma Benign Malignant Carcinoma of the larynx or stomach

Asbestos-Related Disease Lung Cancer Either squamous cell or adenocarcinoma Bronchogenic ca is almost always associated with cigarette smoking 90x more common in smokers, 5x more common in Frequently at lung base Associated with increased risk of stomach cancer non-smokers

Thank you…