Mesothelioma, also called 'malignant mesothelioma' is pronounced 'mee-zoh-thee-lee-oh-mah'. It is sometimes called 'meso' for short, by people who have, or work with, the disease. But people generally use the full name.
Mesothelioma is one of the more difficult diseases that people, their doctors, friends and families have to face. It is a form of cancer, almost always caused by exposure to asbestos many years ago.

Mesothelioma in the chest
Your chest lining has two layers. The inner layer lines your lung, and the outer layer lines your chest wall. The space between the two layers contains a small amount of fluid. This lubricates the two surfaces and lets the lung and chest wall move and expand as you breathe. When a tumour grows within the chest lining, it causes it to thicken at first. Then it spreads within the space between the layers. The tumour often produces fluid, sometimes several litres.

Mesothelioma in the abdomen
Your abdominal cavity (the bit below your diaphragm) and bowel are also covered by a lining. Like your chest lining, it has two layers. The inner layer covers the organs in your abdomen (your stomach, etc), and the outer layer lines the wall of your abdomen. A tumour can start within this lining. It causes the lining around the organs in your abdomen to thicken. Lots of fluid can also be produced, which causes swelling of the abdomen.

How does mesothelioma develop?
Mesothelioma usually spreads slowly, taking the path of least resistance. This is initially within the space between the layers of the lining of your chest/abdomen. In later stages, the tumour can grow to be very large. Mesothelioma does not usually spread around the body like other cancers sometimes do.