Pleural mesothelioma

Mesothelioma is a type of cancer that starts from mesothelial cells. These cells line the outer surface of most of the body’s internal organs, creating a protective membrane called the mesothelium.

Some mesotheliomas form a mass (tumour), while others grow along the mesothelium and form a thick covering. In later stages, mesothelioma may spread (metastasise) to other parts of the body.

Learn more about:

• What is pleural mesothelioma?
• How pleural mesothelioma affects the pleura
• What causes mesothelioma?
• How common is mesothelioma?
• Can I seek compensation?
• What can I expect after diagnosis?

What is pleural mesothelioma?

The mesothelium that covers each lung is called the pleura. Mesothelioma that develops in the pleura is known as malignant pleural mesothelioma or, simply, pleural mesothelioma. About 90% of all mesotheliomas are in the chest.

Although pleural mesothelioma involves the lining of the lungs, it is not lung cancer and is diagnosed and treated differently.

The pleura

There are two thin layers of tissue in the pleura. The inner layer (the visceral pleura) lines the lung surface, and the outer layer (the parietal pleura) lines the chest wall and diaphragm.

Between the two layers is the pleural cavity (also called the pleural space), which normally contains a thin film of fluid. This fluid allows the two layers of pleura to slide over each other so the lungs move smoothly against the chest wall when you breathe. When mesothelioma develops in the pleura, the layers of the pleura thicken and may press on the lung, preventing it from expanding when breathing in (inhaling). Excess fluid often collects between the two layers – this is known as pleural effusion.

Other types of mesothelioma

• Peritoneal mesothelioma – Sometimes mesothelioma develops in the lining of the abdomen. This accounts for about 10% of cases and is called malignant peritoneal mesothelioma. Learn more about peritoneal mesothelioma.
• Pericardial mesothelioma – Rarely, mesothelioma occurs in the pericardium, the mesothelium covering the heart. This is called pericardial mesothelioma.
• Testicular mesothelioma – Even more rarely, mesothelioma can occur in the membrane around the testicles, the tunica vaginalis. This is called testicular mesothelioma.

How pleural mesothelioma affects the pleura (the membrane that covers the lungs)

Pleural mesothelioma affects the pleura, the membrane that covers the lungs. The lungs are the main organs for breathing and are part of the respiratory system, along with the nose, mouth, windpipe (trachea), large airways (bronchi) and smaller airways (bronchioles). The lungs rest on the diaphragm, which is a wide, thin muscle that makes you breathe.

The respiratory system

What causes mesothelioma?

Exposure to asbestos fibres or asbestos dust is the main cause of mesothelioma, but in some cases there is no clear link to asbestos.

What is asbestos – Asbestos is the name of a group of naturally occurring minerals that are resistant to high temperatures and humidity. It was used in many building products in Australia from the 1940s until 1987. Since 2004, Australia has banned asbestos being sold, reused and/or imported. Despite the ban, asbestos has been found in some products recently imported from overseas. It is still found in many older buildings, so special care needs to be taken when renovating.

Highest risk groups – People who may have been exposed to asbestos at work include: builders, plumbers and electricians; boilermakers and welders; asbestos miners; asbestos cement manufacturing workers; insulators; automotive industry workers; mechanics; transport workers (especially waterside workers); and textile workers.

People who haven’t worked directly with asbestos but have been exposed to it can also develop mesothelioma. These can include people cleaning work clothes with asbestos fibres on them, or people disturbing asbestos during home renovations or maintenance.

It can take many years for mesothelioma to develop after a person is exposed to asbestos. This is called the latency period or interval – it is usually between 20 and 60 years (most commonly around 40 years) after exposure.

How common is mesothelioma?

Australia has one of the highest rates of mesothelioma in the world, with 757 Australians diagnosed in 2016. Men are four times more likely than women to be diagnosed with mesothelioma, probably because many cases have been caused by exposure to asbestos at work.

Pleural mesothelioma makes up about 93% of all mesothelioma cases. Peritoneal mesothelioma is less common and makes up nearly 7% of cases. Mesothelioma is more common in people over the age of 65, but can occur in younger people.

Can I seek compensation?

People who develop mesothelioma due to asbestos exposure may be able to claim compensation. Start making notes and talking to family and friends about when you may have been exposed to asbestos. It is important to get advice from an experienced lawyer as soon as possible after diagnosis because a case for compensation must be started within your lifetime. Mesothelioma or asbestos support groups may be able to help you.

See Making a Claim to learn more about seeking compensation.

What can I expect after diagnosis?

You are likely to feel shocked and upset when told you may have mesothelioma. It’s common to have many questions and concerns about what the diagnosis will mean for you.

• Diagnosis – You will have various tests to confirm a diagnosis of mesothelioma and work out how far it has progressed. The results will help you and your health professionals make decisions about treatment.
• Treatment – Depending on how advanced the mesothelioma is and other factors, treatment may achieve a longer period of disease control and improve quality of life.
• Managing symptoms – For many people, the main goal of treatment will be to manage symptoms and improve quality of life. Depending on how mesothelioma affects your health, you may have periods of relatively good health when symptoms are under control or less active. You may also have periods when symptoms need to be relieved with more intensive treatment.