Definition

A rare type of cancer in which malignant cells are found in the sac lining the chest or abdomen. Exposure to airborne asbestos particles increases one's risk of developing malignant mesothelioma.

The body attempts to clear the fibers through phagocytosis but when cells try to digest the fibers they burst and their contents scar the alveoli of the lung which can then lead to mesothelioma. It is found in 3 places, the pleura, the pericardium, and the peritoneum.

Source

Source: The National Cancer Institute (NCI)
Mesothelioma Web