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. Have you been diagnosed with malignant mesothelioma? You are not alone. Here is a list of good support groups that can give you the information about mesothelioma that you need and put you in touch with other people that are in the same shoes as you.