Mesothelioma is a rare but deadly type of cancer usually caused by exposure to asbestos or asbestos-containing products. The mesothelium is a thin mucous membrane that covers most major organs, and provides the moisture the organs need to move properly. Lubrication allows organs to move in order to circulate blood in the heart, or infuse it with oxygen in the lungs, or process food properly in the gastrointestinal tract.

There are several different kinds of mesothelioma, but by far the most common is pleural, or lung-related mesothelioma. As asbestos enters the body through respiration, the microscopic shards pierce the lungs and lodge in the delicate pleural mesothelium. The shards irritate and fester in the mesothelium, and over time will most likely develop into mesothelioma. Most cases of this cancer take decades before any symptoms begin to appear, but by the time they manifest they are too advanced to treat.

Other kinds of mesothelioma include pericardial mesothelioma, which affects the lining around the stomach and digestive tract; and pericardial mesothelioma that affects the lining of the sac that contains the heart. Most mesothelioma prognoses are not positive; victims rarely live longer than five years after their first diagnosis, and most succumb between six and 12 months.

Many experts call mesothelioma the