Mesothelioma Flashcards
What is the definition of mesothelioma?
Malignant mesothelioma is an aggressive epithelial neoplasm arising from the lining of the lung, abdomen, pericardium, or tunica vaginalis.
Epidemiology of mesothelioma
- 45,221 deaths from mesothelioma were reported in the US between 1999 and 2015
- Often presents in patients >60 years old due to a latent disease period
- M>F
RFs of Mesothelioma
- Increasing age: often presents in patients >60 years old due to a latent disease period
- Male gender
- Asbestos exposure: construction/demolition work, dock/shipyard work, electricians, plumbers, painters and carpenters.Crocidolite (blue asbestos)has the highest risk.
- Other causes: include radiotherapy, genetics, simian virus 40
What is mesothelioma?
epithelial malignancy of the mesothelial cells of the pleura covering the lungs (and epithelial cells of other organs)
What is the primary cause of mesothelioma?
asbestos exposure, with the development of the malignancy occurring 20-40 years after exposure (after a long latent period).
What do the asbestos fibres do?
- asbestos fibres make their way to the mesothelium and can get tangled up with the cell’s chromosome.
- Asbestos is also believed to result in macrophage and neutrophil activation, consequently generating reactive oxygen and nitrogen species.
- This causes DNA damage and modification in gene expression, thus increasing the risk of cancer.
Over time what happens in mesothelioma?
Mesothelial plaques start to cover the visceral pleura over the lungs and the parietal pleura under the chest wall. These growths start to express a lot of calretinin, a calcium-binding protein, involved in regulating calcium levels within the cell
What does asbestos exposure cause?
spectrum of disease, from pleural plaques and thickening to asbestosis, mesothelioma and lung cancer.
As asbestos fibres can affect epithelial cell, what does this mean for the body?
they can cause mesothelioma in nearly any of the body’s internal organs, but it’s most commonly found in the lungs and abdominal organs - the liver, spleen and bowel - or in very rare cases, the pericardium lining of the heart and testes.
The lymphatics may also be invaded, causing hilar node metastases
Signs of mesothelioma
- Ascites
- Signs of metastes - lymphadenopathy, hepatomegaly
- Finger clubbing
- Reduced breath sounds
- Stony dull percussion: suggests a pleural effusion
Symptoms of mesothelioma
- Shortness of breath
- Cough
- Pleuritic chest pain or chest wall pain
- Bloody sputum: if blood vessels are affected
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Constitutional symptoms:
- Fatigue, fever, night sweats, weight loss
Primary investigations for Mesothelioma
- CXR:unilateral pleural effusion, reduced lung volumes, pleural thickening, lower zone interstitial fibrosis for asbestos
- Contrast-enhanced CT chest:performed following a suspicious CXR and may demonstrate**pleural thickening, pleural plaques and enlarged lymph nodes
What investigation is gold standard for diagnosis?
Thoracoscopy
- Diagnostic pleural aspiration:if there is evidence of a pleural effusion, the fluid should be sent for MC&S, biochemistry and cytology; effusions areexudative.
- Immunohistochemistry:selective markers are positive in mesotheliomas, such as calretinin, nuclear WT1 and keratins 5/6
Management of operable mesothelioma
Surgery
- Extrapleural pneumonectomy
- Pleurectomy with decortication (removing the pleural lining + tumour masses)
- Rarely curative
+/- Chemotherapy
- Cisplatin
- Pemetrexed
+/- Radiotherapy
Management of inoperable mesothelioma
Chemotherapy
- Cisplatin
- Pemetrexed
+/- Radiotherapy
