Mesothelioma is a rare form of cancer in which malignant (cancerous) cells are found in the mesothelium, a protective sac that covers most of the body's internal organs. Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles. : http://www.mesothelioma-articles.net/Mesothelioma-Cancer-Strikes-Years-Later/30