What is mesothelioma?

Mesothelioma is a cancer of mesothelial cells which cover the outside of most of our internal body organs. It forms a lining which is sometimes known as the mesothelium.

Mesothelioma cancer can develop in the tissues covering the lungs or abdomen.

The tissues covering the lungs are known as the pleura, of which there are two. Sometimes called pleural membranes, the gap between them is called the pleural space. The pleura are fibrous sheets and they help to protect the lungs, producing a lubricating fluid that fills the gap between the two pleura. This helps the lungs to move smoothly in the chest when we breathe.

Mesothelioma is most commonly diagnosed in the pleura and is known as pleural mesothelioma. As it is so close, pleural mesothelioma can also affect the sheet of tissue covering the heart - the pericardium. Doctors refer to the pericardium as the lining, even though it is on the outside of the heart. It helps to protect and allow the heart to move smoothly within the sac that surrounds it. Basically, it does much the same job for the heart as the pleura do for the lungs.

The tissue lining the abdomen is known as the peritoneum, and helps to protect the abdomen. It also produces a lubricating fluid to help the organs to move smoothly inside the abdomen as we move around.

Mesothelioma of the tissues lining the abdominal cavity os referred to as peritoneal mesothelioma, and is much less common than pleural mesothelioma.

It is not usual for mesothelioma to spread to other parts of the body. It does not usually cause troublesome symptoms if it does.

There is also a form of non cancerous (benign) mesothelioma which can develop within the lining of the lungs, or in the lining of the reproductive organs. This can occur in either men or women but these non cancerous tumours are very rare.
Mesothelioma risks and causes