Mesothelioma (cancer of the mesothelium) is a disease in which cells of the mesothelium become abnormal and divide without control or order. They can invade and damage nearby tissues and organs. Cancer cells can also metastasize (spread) from their original site to other parts of the body. Most cases of mesothelioma begin in the pleura or peritoneum.

Mesothelioma is a benign (noncancerous) or malignant (cancerous) tumor affecting the lining of the chest or abdomen. Exposure to asbestos particles in the air increases the risk of developing malignant mesothelioma. The Mesothelioma is a rare form of cancer that involves the mesothelium, or cells that line an organ, abdominal organs, usually the lungs, and heart. The most common form of mesothelioma is pleural mesothelioma, where the malignant tumors form on the pleura, the sac that lines the chest cavity and protects the lungs. Other forms of mesothelioma affect the peritoneum (abdominal cavity lining) and the pericardium (which is lining around the heart).

Mesothelioma is usually caused by asbestos exposure. Asbestos mesothelioma is a fibrous mineral known to be carcinogenic. People who are exposed to asbestos fibers for just a short period of time (few weeks) or even to a small amount may be at risk. In particular, people working with asbestos and their family members or those who live with them develop mesothelioma. There is a long latency period between initial exposure to asbestos and the development of malignant tumors. On average, 35-40 years elapse before the onset of disease.

The early symptoms of mesothelioma can resemble pneumonia, including shortness of breath, difficulty breathing, persistent cough, chest and abdominal pain. Often, there is fluid buildup between the pleura and chest cavity (called pleural effusions), which leads to dyspnea (shortness of breath) and sometimes pain. Some people may not have any symptoms.

Treatment for mesothelioma cancer can be surgery to remove the tumors, chemotherapy, radiation, or a combination of the three. Depending on the person’s health, time of diagnosis, and other factors, the survival rate is about four to 12 months from the onset of symptoms. However, occasionally people may live longer.