Malignant Mesothelioma Malignant mesothelioma, a rare form of cancer, is a disease in which cancer (malignant) cells are found in the sac lining the chest (the pleura) or abdomen (the peritoneum). Most people with malignant mesothelioma have worked on jobs where they breathed asbestos. A doctor should be seen if a person has shortness of breath, pain in the chest, or pain or swelling in the abdomen. If there are symptoms, the doctor may order an x-ray of the chest or abdomen. The doctor may look inside the chest cavity with a special instrument called a thoracoscope. A cut will be made through the chest wall and the thoracoscope will be put into the chest between two ribs. This test, called thoracoscopy, is usually done in the hospital. Before the test, the patient will be given a local anesthetic (a drug that causes a loss of feeling for a short period of time). Some pressure may be felt, but usually there is no pain. The doctor may also look inside the abdomen (peritoneoscopy) with a special tool called a peritoneoscope. The peritoneoscope is put into an opening made in the abdomen. This test is also usually done in the hospital. Before the test is done, a local anesthetic will be given. If tissue that is not normal is found, the doctor will need to cut out a small piece and have it looked at under a microscope to see if there are any cancer cells. This is called a biopsy. Biopsies are usually done during the thoracoscopy or peritoneoscopy. The chance of recovery (prognosis) depends on the size of the cancer, where the cancer is, how far the cancer has spread, how the cancer cells look under the microscope, how the cancer responds to treatment, and the patient’s age. Stages of Malignant Mesothelioma Once malignant mesothelioma is found, more tests will be done to find out if cancer cells have spread to other parts of the body. This is called staging. A doctor needs to know the stage of the cancer to plan treatment. The following stages are used for malignant mesothelioma. Localized Malignant Mesothelioma Stage I - The cancer is found in the lining of the chest cavity near the lung and heart or in the diaphragm or the lung. Advanced malignant mesothelioma Stage II - The cancer has spread beyond the lining of the chest to lymph nodes in the chest. Stage III - Cancer has spread into the chest wall, center of the chest, heart, through the diaphragm, or abdominal lining, and in some cases into nearby lymph nodes. Stage IV - Cancer has spread to distant organs or tissues. Recurrent Malignant Mesothelioma Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may come back in the lining of the chest or abdomen or in another part of the body.