Asbestosis

Question 1

What are the five conditions associated with asbestos exposure?

Answer 1

• Asbestosis
• Malignant mesothelioma
• Lung cancer (e.g., bronchogenic carcinoma)
• Laryngeal cancer
• Ovarian cancer

Asbestos exposure can lead to several serious health conditions, primarily affecting the respiratory system and related cancers.

Question 2

Define asbestosis.

Answer 2

Pneumoconiosis characterised by interstitial lung fibrosis and parenchyma involvement resulting from chronic asbestos exposure.

Asbestosis is a chronic lung disease caused by inhaling asbestos fibers, leading to lung scarring.

Question 3

What is malignant mesothelioma?

Answer 3

Malignant cancer originating from the mesothelium lining of the lungs, chest wall (pleura), and abdomen (peritoneum).

This cancer is strongly associated with asbestos exposure.

Question 4

What is the epidemiological significance of asbestos exposure?

Answer 4

Results from cumulative asbestos exposure over 20-40 years.

Asbestos-related diseases were most prevalent in workers in industries like milling, mining, and construction before the late 1970s.

Question 5

Which professions are most likely to be affected by asbestos exposure today?

Answer 5

• Construction trades
• Demolition workers
• Plumbers
• Electricians
• Miners
• Railway engineers
• Builders
• Shipyard workers

These professions involve potential exposure to asbestos-containing materials.

Question 6

What is the pathophysiology of asbestos exposure?

Answer 6

Alveolar macrophages attempt to engulf inhaled asbestos fibres, causing:
* Persistent immune responses
* Generation of profibrotic and proinflammatory cytokines
* Inflammation
* Oxidative stress
* Collagen deposition
* Fibre formation

Asbestos fibers are also directly toxic to lung tissue.

Question 7

What are the types of asbestos?

Answer 7

• Chrysotile (white asbestos)
• Amosite (brown asbestos)
• Crocidolite (blue asbestos)

Each type of asbestos has distinct uses and associated health risks.

Question 8

What is the most dangerous form of asbestos?

Answer 8

Crocidolite (blue asbestos)

It is the most likely type to cause malignant mesothelioma.

Question 9

What are the initial symptoms of asbestosis?

Answer 9

• Slowly progressing dry cough
• Dyspnea (shortness of breath)

Symptoms worsen with exertion over time.

Question 10

List the common respiratory exam findings in asbestosis.

Answer 10

• Clubbing
• Edema
• Jugular venous distension
• Fine end-inspiratory crackles

These findings are indicative of lung pathology related to asbestos exposure.

Question 11

What are the typical presentations of malignant pleural mesothelioma and lung cancer?

Answer 11

• Ongoing chest pain
• Dyspnea
• Weight loss
• Pleural effusion (which can cause abdominal swelling and pain)

These symptoms are critical for diagnosis and indicate advanced disease.

Question 12

What are the common chest x-ray findings in asbestosis?

Answer 12

1. Pleural plaques usually in diaphragmatic pleura
2. Bilateral pleural thickening of middle zones
3. Unclear heart edges due to diffuse reticulonodular opacities mostly at lung bases

Question 13

What are the common HRCT findings in asbestosis?

Answer 13

1. Calcified pleural plaques near lung bases and posterior to ribs
2. Parenchymal bands: Linear opacities starting from visceral pleura

Early asbestosis: Increased interstitial markings
Advanced asbestosis: Honeycomb appearance

Question 14

What is observed in a lung biopsy for asbestosis?

Answer 14

Asbestos bodies with characteristic long-beaded appearance and clubbed ends

Question 15

What are the common HRCT findings in malignant pleural mesothelioma?

Answer 15

1. Asymmetrical nodular pleural thickening
2. Unilateral pleural effusion
3. Lung volume loss
4. Interlobular fissure thickening

Question 16

What is observed in a pleural biopsy for malignant pleural mesothelioma?

Answer 16

Epithelioid, sarcomatoid or biphasic

Question 17

What is the role of immunohistochemistry in malignant pleural mesothelioma?

Answer 17

Identify positive mesothelial immunohistochemical markers and distinguish from adenocarcinomas and other carcinomas

Question 18

What is the management for asbestos-related lung disease?

Answer 18

Asbestos damage is irreversible but progression can be reduced through various methods.

Methods include pulmonary rehabilitation, smoking cessation, supplemental oxygen, lung transplant, and antifibrotic drugs.

Question 19

What does pulmonary rehabilitation include?

Answer 19

Pulmonary rehabilitation includes breathing exercises, anxiety and depression counselling, nutrition counselling, and education.

These components help improve lung function and overall well-being.

Question 20

What are antifibrotic drugs used for in asbestos-related lung disease?

Answer 20

Antifibrotic drugs, such as Nintedanib and pirfenidone, are used to manage asbestos-related lung disease.

They help slow down the progression of lung fibrosis.

Question 21

What treatments are available for malignant mesothelioma and lung cancer?

Answer 21

Treatments include immunotherapy, targeted therapy, and palliative care.

Immunotherapy examples are Nivolumab and ipilimumab; targeted therapy includes Bevacizumab.

Question 22

What is the role of palliative care in lung cancer management?

Answer 22

Palliative care focuses on relieving symptoms and improving quality of life, which may involve surgery and radiotherapy.