What is Mesothelioma?
Mesothelioma is an incurable cancer caused by the inhalation of asbestos dust and fibre. Mesothelioma usually affects the lining of the lung (called the pleura) however in some instances it can affect the lining of the abdominal cavity (called the peritoneum). These types of mesothelioma are known as pleural mesothelioma and peritoneal mesothelioma respectively.
Mesothelioma occurs when asbestos fibres affect the pleura or peritoneum and cause it to form a thickening/mass. This restricts the lung movement and causes pleural fluid to accumulate in the lung. In the case of peritoneal mesothelioma, it affects movement of the gastrointestinal tract. Pleural mesothelioma is by far the most common form of the condition however rarer forms of mesothelioma include pericardial and testicular mesothelioma being mesothelioma of the heart and testicles.
SubTypes of Mesothelioma
There are 2 well recognised subtypes of mesothelioma, epithelioid and sarcomatoid. A person can suffer from one or more subtypes of mesothelioma. Persons who have both subtypes of mesothelioma are considered to have biphasic mesothelioma. The main difference between these two subtypes is the rate at which the mesothelioma develops and progresses.
Cause of Mesothelioma
There is only one accepted cause of mesothelioma in Australia and that is asbestos exposure. Sadly, mesothelioma can be caused by even small exposures to asbestos such as when installing a fence or when carrying out a renovation. Cigarette smoking does not cause mesothelioma.
Mesothelioma has many symptoms, which vary depending on where the cancer is located, the most common of which include:
- Chest pain (caused by the tumour itself or the fluid in the lung) which manifests in a dull ache, stabbing or burning pain
- Loss of appetite
- Weight loss
- Night sweats
- A persistent dry cough
- Lumps on the chest
- A painful and/or swollen abdomen (peritoneal mesothelioma)
Pleural mesothelioma is usually diagnosed after a routine chest x-ray or CT scan or after a person presents to their doctor with one or more of the symptoms set out above and are referred for a chest x-ray or CT scan.
Radiological scanning usually shows a person is suffering from a pleural effusion or pleural thickening. After discovery of these features a person is generally referred for a pleural aspiration where the pleural fluid is drained from a person’s lung. The fluid is drained for relief of symptoms (breathlessness and chest pain) and a small sample is sent away for testing.
Sometimes a diagnosis is unable to be made on the pleural fluid and on these occasions a person is referred to a cardiothoracic surgeon who performs a pleural biopsy where a sample of the tumour is taken and examined under a microscope. There are several methods a doctor may utilise to perform their biopsy including a fine needle biopsy, a CT guided pleural biopsy or a video assisted thorascopic (VATS) biopsy.