What is Mesothelioma lung cancer?

Mesothelioma is the term used to describe a cancerous tumor that involves the mesothelial cells of an organ. Mesothelial cells are cells that form a protective lining over the lungs, heart and abdominal organs. The most common type of mesothelioma is pleural mesothelioma. The pleura is a thin membrane found between the lungs and the chest cavity. It provides a lubricated surface so that the lungs do not rub and chafe against the chest walls.