Mesothelioma is the most common case of cancer related to asbestos exposure. It is, however, a rare disease, registering about 3,000 new cases annually in the US. This type of cancer affects the mesothelium, which is a thin protective membrane that forms the lining of some organs. It can take 20 to 50 years between asbestos exposure and the onset of mesothelioma. The disease can affect the lining of the lungs, abdomen, heart or testicles, known as pleural mesothelioma, peritoneal mesothelioma, pericardial mesothelioma and testicular mesothelioma, respectively. Each form of the disease causes different types of symptoms, but pain and shortness of breath are among the most common regardless of the diagnosis.