Mesothelioma Flashcards
What is the median age of presentation of mesothelioma?
60 years
What does mesothelioma typically present after?
20-50 years after asbestos exposure
What is the male to female ratio of mesothelioma?
5:1
How is the risk of mesothelioma related to asbestos exposure?
It is estimated that the risk is linearly proportional to the intensity and duration of exposure
What is the risk of the risk of mesothelioma being proportional to the intensity and duration of asbestos exposure?
The latency periods between first exposure to asbestos and diagnosis of mesothelioma may vary by occupation, with shorter intervals for insulators and dock workers, and longer intervals for shipyard and maritime workers, as well as domestic exposures
What do a significant proportion of patients diagnosed with mesothelioma diagnosed between the ages of 20 and 40 report?
Household or neighbourhood exposure during childhood
Do children who present with mesothelioma have a history of asbestos exposure?
They generally have no apparent asbestos exposure
How long is it estimated that the incidence of mesothelioma will rise for?
Until 2020
Why is the incidence of mesothelioma expected to fall after 2020?
Due to increasing awareness of the role of asbestos, and measures to reduce asbestos exposure
How common is malignant mesothelioma?
Rare, <1% of cancers
Is malignant mesothelioma aggressive?
Yes, highly aggressive
Where does malignant mesothelioma arise from?
Primarily from the surface serosal cells of the pleural, peritoneal, and pericardial cavities
What is the primary cause of malignant mesothelioma?
Exposure to asbestos fibres
What % of patients with malignant mesothelioma have no history of exposure to asbestos fibres?
50%
How does the risk of malignant mesothelioma vary depending on which kind of asbestos fibre the patient is exposed to?
It is highest with blue fibres (crocidolite), then brown (amosite), and least with white (chrysolite)
What virus is a possible co-factor for malignant mesothelioma?
SV40
Why is it thought that SV40 is a possible co-factor for malignant mesothelioma?
In 60-83% of human malignant mesotheliomas, the cells express SV40 DNA
How does exposure to asbestos fibres cause malignant mesothelioma?
The exposure can produce reactive oxygen species when hydrogen peroxide and superoxide react to form hydroxyl radicals, which can induce DNA damage
What % of patients with malignant mesothelioma present with intrathoracic symptoms?
90%
What are the intrathoracic symptoms of malignant mesothelioma?
- Cough
- Dyspnoea
- Non-pleuritic chest wall pain
What symptoms can involvement of the mediastinal pleura in malignant mesothelioma cause?
- Arrhythmias
- Dysphagia
How common are symptoms due to the involvement of the mediastinal pleura in malignant mesothelioma?
Rare
What systemic symptoms are common in mesothelioma?
- Pyrexia of unknown origin
- Sweats
- Anorexia
- Weight loss
What are the less common symptoms of malignant mesothelioma?
- Thrombocytosis
- Disseminated intravascular coagulation
- Thrombophlebitis
- Haemolytic anaemia
What examination features do most patients with malignant mesothelioma present with?
- Dullness at one lung base
- Unilateral pleural effusion on CXR
Can malignant mesothelioma present incidentally?
Yes, occasionally patients can present asymptomatically with effusion as an incidental finding
What % of patients with malignant mesothelioma have bilateral involvement at the time of diagnosis?
Less than 5%
What % of patients with malignant mesothelioma have right sided lesions?
60%
What is the predominant method by which malignant mesothelioma spreads?
Local invasion of the lung, extending into the fissures and interlobular septa, adjacent organs in the mediastinum and chest wall, and may track along chest drainage sites
What % of patients have thoracic lymph node invasion in malignant mesothelioma?
Up to 70%
Where do haematogenous metastases of malignant mesothelioma commonly spread to?
- Liver
- Lung
Where do haemotogenous metastases of malignant mesothelioma less commonly spread to?
- Kidney
- Adrenals
- Bone
What lymph nodes should be examined in malignant mesothelioma?
- Neck
- Supraclavicular
- Axillary
What should be looked for on hand examination in malignant mesothelioma?
- Clubbing
- Signs of smoking