Mesothelioma is a lung cancer that affects the mesothelium of the lung. Mesothelium is a membrane that covers the lungs and other organs. It is often caused due to prolonged exposure to asbestos. Other causes include zeolites, radiation, and more. Treatments include surgery, radiation, and chemotherapy. Follow the links below to find WebMD's comprehensive coverage about how mesothelioma is contracted, what it looks like, how to treat it, and much more.