What is Mesothelioma?

Mesothelioma is a form of cancer of the mesothelium that is primarily caused by exposure to asbestos particles. Though seventy to eighty percent of all cases of mesothelioma are reported to be a result of exposure to asbestos, there are some cases of mesothelioma where there is no such known exposure. The mesothelium is the protective sac or membrane that covers most internal organs of the body. With mesothelioma, malignant cancer cells exist in these protective sacs. Mesothelium has two distinct layers. One layer is an internal layer that immediately surrounds the organ.