What is Mesothelioma?

Mesothelioma is a cancer of the mesothelium — the tissue layer that lines the abdomen, chest cavity, heart, and lungs. This rare but aggressive cancer is caused by exposure to asbestos. Exposure occurs when airborne asbestos fibers are inhaled and become lodged in the lungs or abdomen, or around the heart or testicles. These fibers can accumulate and cause scarring and inflammation that can affect breathing and lead to disease.

The most common type of mesothelioma is called "pleural mesothelioma." Pleural mesothelioma occurs when the cancer is found in the pleura, the mesothelial tissue surrounding the lungs and lining of the chest cavity. When cancer is found in the peritoneum lining that covers most of the organs in the abdomen area, it is known as "peritoneal mesothelioma". Pericardium is the lining that covers and protects the heart. When mesothelioma cancer is found in this lining, it is called "pericardial mesothelioma". In men, it is rare, but mesothelioma may be found in the serous membrane, or tunica vaginalis, which is called "testicular mesothelioma".

Mesothelioma, like other forms of cancer, occurs when cells become abnormal and grow out of control or divide. In mesothelioma patients, the lubricating fluid in the lining may be over-produced. This excess fluid creates a rind type of layer of thick tumor tissue and puts pressure on the organs it surrounds. Patients with pleural mesothelioma often experience shortness of breath and a buildup of fluid in the chest area. As mesothelioma advances, the cancer cells metastasize, growing and invading other organs and spreading to other areas of the body.

Asbestos exposure is the only known cause of mesothelioma cancer.

There is often a latency period of 10 to 60 years after asbestos exposure before the symptoms of mesothelioma develop. Because of this long latency period, the disease commonly affects men and women that are at least 50 years of age who worked with asbestos between 10 and 60 years ago.