Mesothelioma

Question 1

Define

Answer 1

• Aggressive tumour of the mesothelial cells, which usually occurs in the pleura (90%) but can also occur in other sites, such as the peritoneum, pericardium and testes.
• NOTE: malignant pleural mesothelioma rarely spreads to distant sites but most patients present with locally advanced disease

Question 2

What’s the aetiology?

Answer 2

• Strongly related to ASBESTOS exposure
• The most frequent somatic mutations are neurofibromatosis type 2 (NF2), BRCA1- associated protein-1 (BAP1), and Cullin 1 (CUL1) genes.

Question 3

What’s the epidemiology?

Answer 3

• RARE
• More common in ELDERLY (> 75 yrs)
• White males
• Asbestos exposure is documented in 70-80% of cases
• Family history
• Latent period between asbestos exposure and mesothelioma may be up to 50 yrs

Question 4

What are the presenting symptoms and signs?

Answer 4

•	MOST COMMON symptoms:
o	SOB
o	Chest pain (dull, diffuse and progressive) 
o	Weight loss 
•	Occasionally palpable chest wall mass 
•	Fatigue 
•	Fever 
•	Night sweats 
•	Diminished breath sounds
•	Dullness to percussion
•	Clubbing (due to underlying asbestosis (pulmonary fibrosis))
•	Signs of metastases (e.g. hepatomegaly, bone pain and tenderness)

Question 5

What are the appropriate investigations?

Answer 5

• CXR/CT

o Shows pleural effusion
o May show a pleural mass and rib destruction
o CT scan more sensitive, provides more detail of pleura, lungs and mediastinum: Findings suggesting a malignant process include circumferential or nodular pleural thickening, involvement of the mediastinal pleura, or enlarged regional lymph nodes.
• MRI (can differentiate between benign or malignant) and PET
• Pleural fluid - can be sent for cytological analysis and may be blood-stained
• Pleural biopsy