Mesothelioma cancers are caused by inhaling asbestos fibers. Asbestos fiber particles look like they have small barbs or hooks on the end of them. Once the fibers are inhaled, the barbed ends embed in the lining of various cavities and the tissue linings of the body. There is no way for the fibers to be removed. Over time, the particles cause scarring and eventually tumors wherever they become embedded. Although most mesothelioma tumors are found in the lungs, there are several different areas of the body mesothelioma can effect.