What is Mesothelioma?

What is


In the UK, over 2,700 per year are diagnosed with mesothelioma. It is also known as ‘diffuse’ or ‘malignant’ mesothelioma. Mesothelioma is a form of cancer that affects the mesothelium.

The mesothelium is a thin membrane that lines the inner surface of: 

  • The chest wall, where it is known as the pleura 
  • The abdomen where it is known as the peritoneum 
  • The testicles

The mesothelium also surrounds organs within these cavities for example the heart, lungs and intestines. It is far more common to have mesothelioma in the chest than in the abdomen. There is approximately one case of peritoneal mesothelioma to every 12 cases of pleural mesothelioma. 

Mesothelioma is more common in men than in women and nearly half of the people diagnosed with the disease are over 75 years old.  

Exposure to asbestos is responsible for up to 9 out of 10 mesothelioma cases. There are thought to be other rare causes of the disease but none are fully understood at this time. More information on asbestos can be found here.  

For more information about the different types of mesothelioma:

(3 minutes)