Malignant mesothelioma is a rare form of cancer that affects the mesothelial cells of the serous membranes in the body. The most common form of mesothelioma, affecting the lining of the lung, is pleural mesothelioma. Two to three thousand new cases of malignant mesothelioma are diagnosed each year.
Malignant mesothelioma takes on three forms:
All mesotheliomas are now considered to be malignant, or cancerous. They start as a localized tumor and spread rapidly to include most of the surrounding tissues and organs. Originally, fibrous cists and other non-cancerous growths that appeared in the serous membranes were thought to be mesotheliomas and were termed "benign fibrous mesothelioma" and "multicystic mesothelioma." These conditions are now known not to originate in the mesothelial cells, but other cells within the serous membranes. These conditions are typically localized, non-cancerous and do not spread rapidly.
- Peritoneal mesothelioma, in the peritoneum or membrane surrounding the abdomen. A rare form of peritoneal mesothelioma can also affect the male testicles, because the lining around the scrotum is an extension of the peritoneum.
- Pericardial mesothelioma, in the perdicardium or lining surrounding the heart.
- Pleural mesothelioma, which is the most common form of malignant mesothelioma and affects the lining of the lung cavity.
Most cases of malignant mesothelioma are associated with a previous exposure to fibrous minerals, of which asbestos is the most important.
*For articles regarding treatment of mesothelioma and other asbestos-related illnesses, as well as links to related web sites, please see our Articles and Resources section.