Malignant mesothelioma is a rare cancer in which malignant or cancerous cells form in the thin layers of tissue lining the human chest, heart or abdomen. When the cancer is in the chest, it affects the pleura or tissue lining the lungs and is called malignant plural mesothelioma. This is the most common type of mesothelioma. In the abdomen, a cancer of the peritoneum or tissue lining the abdominal cavity and covering various organs is called malignant peritoneal mesothelioma. The least common form of mesothelioma affects the pericardium, or outer lining of the heart. The term mesothelioma literally means a growth of the mesothelioma, a layer of tissue from which the pleura, peritoneum and pericardium all develop.
The majority of malignant mesothelioma's occur in people who have been exposed to asbestos, either directly or via people they live with. Avoiding exposure to asbestos can largely prevent malignant mesothelioma's. Depending on the location of the cancer, someone with malignant mesothelioma may have one or more of the following symptoms: breathlessness, pain under the rib cage or in the abdomen, an abdominal lump or swelling, and unexplained weight loss.
If a detailed medical history and physical exam suggests malignant mesothelioma as a possible diagnosis, a variety of diagnostic tests may be performed, including blood tests, x-rays, MRIs, CT scans and biopsies. Malignant mesothelioma's are graded upon the extent they have spread. A stage I, or localized, malignant mesothelioma is one that has not spread beyond the area it originated in. Stage II, III and IV malignant mesothelioma's are advanced, and may have spread to lymph nodes or to surrounding or distant organs and tissues. Depending on the stage, a treatment plan may include surgery, radiation therapy or chemotherapy. Some cancer treatment centers are involved in clinical trials using bio therapy and immune therapy.