Mesothelioma Mesothelioma, a form of cancer, develops in the linings of organs. It usually affects the lungs (pleura) but can also affect the lining of the abdomen (peritoneum) as well as the heart or testicles. Mesothelioma is caused by asbestos fibre exposure. Typically, symptoms don't appear until decades after exposure. https://vimeo.com/705042101