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:

SerpentinsChrysotil (white asbestos)

Amphibole

Crocidolith (blue)

Amozith (brown)

Anthophylith

Tremolith

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 DiseasePleural 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…