Lung Cancers

Question 1

What is malignant mesothelioma?

Answer 1

an aggressive cancer that attacks the mesothelium

Question 2

What is the mesothelium?

Answer 2

thin membrane made of epithelial cells, that lines organs and spaces e.g., the thoracic cavity

Question 3

Where does mesothelioma most commonly develop?

Answer 3

in the lining of the lungs and the pleural cavity

Question 4

What carcinogen is mesothelioma well-known to be associated with?

Answer 4

asbestos

Question 5

What was asbestos used for and why?

Answer 5

used to be used in construction materials e.g., paint, insulation, roofing tiles etc.
this was because it has strong fibres that are resistant to fire

Question 6

What happens to asbestos fibres when they are inhaled?

Answer 6

they move to the epithelial cells in the parietal and visceral pleura
over time, they do not break down at all, they stay in the lungs for life, causing inflammation and DNA damage

Question 7

How can does asbestos exposure lead to malignant mesothelioma?

Answer 7

DNA damage caused by asbestos can lead to uncontrolled cell growth and tumour formation in the epithelium

Question 8

What are mesothelial plaques?

Answer 8

small cancerous growths that cover the pleura

Question 9

What do mesothelial plaques express and what does this do?

Answer 9

they express calretinin
this has a role in regulating calcium within cells
this can be used to distinguish mesothelioma from other tumours

Question 10

Where can asbestos end up, as well as the lungs?

Answer 10

in the stomach, if mucus containing asbestos is swallowed

Question 11

What organs are most commonly affected by malignant mesothelioma?

Answer 11

lungs
abdominal organs - liver, spleen, bowels
pericardium and testes in rarer cases

Question 12

List the symptoms of malignant mesothelioma (of the lungs/pleura)

Answer 12

chest pain
SOB
pleural effusions
bloody sputum
pneumothorax in rare cases
systemic symptoms - fatigue, weight changes, sleep pattern changes

Question 13

How is malignant mesothelioma diagnosed?

Answer 13

first line CXR or chest CT showing pleural changes or pneumothorax
final diagnosis made via biopsy of tumour

Question 14

How does a biopsy of malignant mesothelioma appear under the microscope?

Answer 14

reaction with calretinin gives cells a distinctive ‘fried egg’ appearance

Question 15

Summarise the prognosis of malignant mesothelioma

Answer 15

poor unless caught early
cancer is very resilient and has often spread to multiple organs before being detected

Question 16

Summarise the treatment for malignant mesothelioma

Answer 16

depends on stage of cancer
combination of surgery, chemo and radio -therapy
good palliative care is essential in most cases