Mesothelioma is a form of cancer that affecting mesothelial cells. The most common form of mesothelioma affects the lung. More than two thousand cases of malignant mesothelioma are diagnosed each year. One of the most disheartening things about this form of cancer is that most victims do not experience mesothelioma symptoms for 20-30 years following exposure to asbestos, the only known cause of mesothelioma.
Mesothelioma affects the membranes of certain large cavities in the body, called the serous cavities. The membranes that surround these cavities are the serous membranes. The serous membranes derive from specialized cells called mesothelial cells, which form to create the mesothelium. Cancer occurring in the mesothelium tissue is called mesothelioma.
All mesotheliomas are malignant. They start as a localized tumor and spread, to include most of the surrounding tissues and organs. At one time, fibrous cists and other non-cancerous growths in the serous membranes were thought to be mesotheliomas, and were termed "benign fibrous mesothelioma" and "multicystic mesothelioma." They are now known not to originate in the mesothelial cells, but other cells within the serous membranes.
Most malignant mesotheliomas are linked to exposure to fibrous minerals, like asbestos. Indisputable evidence exists of the role of these fibers in the development of mesothelioma. Not everyone who is exposed to asbestos develops mesothelioma, so other factors may also be involved.
Mesothelioma is rare, but it is a deadly disease. It's often in the advanced stages when it is detected, so the outlook for the patients is not as good as it is for cancers that are detected earlier. Regardless, no known form of mesothelioma treatment has proven to be effective.