Condition- Asbestos related lung disease Flashcards
Define Asbestosis
long-term inflammation and fibrosis of the lungs caused by inhalation of asbestos fibres
Define Mesothelioma
aggressive tumour of mesothelial cells that usually occurs in the pleura (90%), and sometimes in peritoneum, pericardium or tunica vaginalis caused by asbestos inhalation
Name three different types of asbestos fibres stating the most carcinogenic version
- Chrysotile (white asbestos) is the least fibrogenic + most common
- Amosite (brown asbestos) has intermediate fibrogenicity
- Crocidolite (blue asbestos) is the most fibrogenic.
State three risk factors for developing asbestosis
- OCCUPATION: shipyard workers, construction, maintenance (20yrs ago so might need occupation history)
- DURATION OF EXPOSURE: The more asbestos inhaled, the greater the risk of developing asbestosis.
- SMOKING: reduces the ability of the lung to clear asbestos fibres
Describe how asbestos inhalation leads to asbestosis
- Asbestos inhaled an gets trapped in alveoli and branches of bronchioles
- Alveolar macrophages become activated and release inflammatory mediators
- Fibrosis of tissue (starting from lower lobes)
- Development of mesothelial plaques which form from acellular colagen (which might calcify)
- Development of pleural effusion
- Deposition of fibrous tissue leads to pleural thickening
What are the risk factors for developing Mesothelioma?
- Family history
- Asbestos exposure (N.B. Crocidolite is the most carcinogenic)
- Aged 60-85
- Previous Radiotherapy
- Genetic Risk: BAP1 mutatation
Which three genes often have mutations in patients with mesothelioma?
- BAP1
- CUL1
- NF2
What is the latency period for mesothelioma and asbestosis?
- Asbestosis: 20years
- Mesothelioma: 20-40years
What are the presenting symptoms of Asbestosis?
- Dry non-productive cough (unless patient has COPD as well)
- SOB
- Tightness
- NO PAIN- chest pain indicates cancer
- History of exposure over 20yrs ago
What are the presenting symptoms of Mesothelioma?
- SOB
- Dry non-productive cough
+
- Chest Pain (dull, diffuse, developing)
- Fatigue, fever, night sweats, weight loss
- Bone pain
- Sometime bloody sputum
What are the signs of Asbestosis?
- Clubbing
- Cyanosis
- Decreased chest expansion
- Fine end-inspiratory crackles at base of lungs
- Diminshed breath sounds
- Dullness to percussion
What are the signs of Mesothelioma?
- Decreased breath sounds
- Pleural rub
- dullness to percussion
- Clubbing (if unerlying asbestosis)
- Occasional palpable chest wall mass
- Sign of metastases: Lymphadenopathy, Hepatomegaly, bone tenderness
- Pneumothorax (RARE)
Which investigations would you conduct to diagose Mesothelioma?
1.CXR/CT: On CT look for enlarged lymph nodes
- Pleural Plaques + calcification (shows up as white)
- Pleaural effusion (can see pleural membranes which you normally wouldn’t)
- Pleural thickening
- Pleural fluid MC&S: If pleural effusion via thoracocentesis
- MRI and PET- differentiate between pleural abnormalities and malignancy
- Video-assisted thoracoscopic surgery (VATS) to look at pleural lining and obtain a biopsy
Which protein is often upregulated in Mesotheliomas, what is its function and importance in diagnosing Mesothelioma?
- CALRETININ
- A calcium binding protein
- The tumour can be immunostained with a stain that reacts with Calretinin (which is quite specific to Mesotheliomas)
What can you see on this CXR and what condition could cause this?
MESOTHELIOMA
- plural thickening
- pleural effusions
- pleural plaques due to asbestos
