Pleural mesothelioma

The mesothelium that covers the lungs is called the pleura. Mesothelioma that develops in the pleura is known as malignant pleural mesothelioma or, simply, pleural mesothelioma. It accounts for more than 90% of all mesotheliomas.

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 layers in the pleura. The inner layer lines the surface of the lungs and is called the visceral pleura. The outer layer lines the chest wall and the diaphragm, and is called the parietal pleura.

Between the two layers is the pleural cavity (also called the pleural space), which normally contains a small amount 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 delicate 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 called a 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.

Australia has one of the highest rates of mesothelioma in the world, with 732 Australians diagnosed in 2014. Of these, more than 93% had pleural mesothelioma, about 6% had peritoneal mesothelioma, and about 1% had a rarer type.

Men are over three times more likely than women to be diagnosed with mesothelioma, probably because many cases have been caused by exposure to asbestos at work. Western Australia has the most cases per population due to past asbestos mining. Mesothelioma is more common in people over the age of 65, but can occur in younger people.

Exposure to asbestos is the main cause of mesothelioma. Very rarely, mesothelioma has been linked with previous radiotherapy to the chest.

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 had a ban on asbestos being sold, reused and/or imported. It is still present in many older buildings, so special precautions must be taken when renovating or demolishing. It has also been found in some recently imported products despite the ban.

People most likely to have been exposed to asbestos at work include asbestos miners and millers, asbestos cement manufacturing workers, laggers and insulators, builders, plumbers and electricians, 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.

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. See Making a Claim to learn more about seeking compensation.

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 stage – You will have various tests to confirm that you have mesothelioma and work out how far it has progressed. The results will allow you and your health professionals to make decisions about the best approach to treatment.
• Treating symptoms – Mesothelioma is often diagnosed at an advanced stage. For most people, the main goal of treatment is to manage symptoms and improve quality of life.
• Active treatment – Depending on how advanced the mesothelioma is and other factors, you may be offered active cancer treatments to achieve a longer period of disease control and improve quality of life.

Depending on the impact of mesothelioma on your health, you may experience periods of relatively good health when symptoms are under control or less active. You may also experience periods when symptoms need more intensive treatment. Find out more about living with mesothelioma and questions you may want to ask your doctor.

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 helps with breathing.