Malignant mesothelioma (me-zoe-thee-lee-O-muh) is a type of cancer that occurs in the thin layer of tissue that covers the majority of your internal organs (mesothelium).
Mesothelioma is an aggressive and deadly form of cancer. Mesothelioma treatments are available, but for many people with mesothelioma, a cure isn’t possible.
Doctors divide mesothelioma into different types based on what part of the mesothelium is affected. Mesothelioma most often affects the tissue that surrounds the lungs (pleura). This type is called pleural mesothelioma. Other, rarer types of mesothelioma affect tissue in the abdomen (peritoneal mesothelioma), around the heart and around the testicles.
Signs and symptoms of mesothelioma vary depending on where the cancer occurs.
Pleural mesothelioma, which affects the tissue that surrounds the lungs, causes signs and symptoms that may include:
Shortness of breath
Unusual lumps of tissue under the skin on your chest
Unexplained weight loss
Other forms of mesothelioma
Signs and symptoms of other types of mesothelioma are unclear, since these forms of the disease are very rare.
Pericardial mesothelioma, which affects tissue that surrounds the heart, can cause signs and symptoms such as breathing difficulty and chest pains.
Mesothelioma of tunica vaginalis, which affects tissue surrounding the testicles, may be first detected as swelling or a mass on a testicle.