Mesothelioma is a rare form of cancer that develops from transformed cells originating in the mesothelium, the protective lining that covers many of the internal organs of the body. It is usually caused by exposure to asbestos.

The most common anatomy site for the development of mesothelioma is the the outer lining of the lungs and internal chest wall, but it can also arise in the lining of the abdominal cavity, and the the sac that surrounds the heart or the sac that surrounds the testis.

Most people who develop mesothelioma have worked in jobs where they inhaled asbestos, or were exposed to asbestos dust and fibers in other ways. It has also been suggested that washing clothes of a family member who worked with asbestos increases their risk for developing mesothelioma.

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