MESOTHELIOMA

Mesothelioma (mez-uh-thee-lee-O-muh) is a type of cancer that begins in the tissue that line different organs and spaces inside the body. This tissue, called mesothelium (mez-uh-thee-le-um), protects organs by making a special fluid that allows the organs to move. For example, this fluid makes it easier for the lungs to move during breathing.

Mesothelium surrounds the lungs, the stomach, the heart, and other organs. Tumors can start in any of these places. These tumors can be benign or they can be cancerous. The information that follows covers only those that are cancerous.

There are three main types of mesotheliomas. The most common (50%-70%) is the epithelioid type. This type has the best outlook. The other two types are less common. The treatment choices for all three are the same.

About three out of four mesotheliomas start in the chest cavity. These are called pleural mesotheliomas. Another 10%-20% begin in the abdomen (peritoneal mesotheliomas). Those starting around the heart are very rare. This cancer can also start in the tissue around the testicles, but this is also very rare.

There are also benign (not cancer) tumors that can start in the mesothelium, but the information here applies only to malignant (cancerous) mesotheliomas.