Mesothelioma Cancer

What is mesothelioma?

Mesothelioma is a rare type of tumor that arises in the mesothelium, a membrane that lines the cavities of the body (such as the chest and abdomen) and also covers and protects most of the body's internal organs. In the chest, the mesothelium is known as the pleura, where it covers the lungs ('visceral pleura') and lines the internal chest wall ('parietal pleura'). There is a 'potential space' between the visceral and parietal pleura, which normally contains about 10 mls of lubricating fluid that reduces friction between the chest wall and the lungs. In the abdomen, the mesothelium is called the peritoneum, while that surrounding the heart is called the peritoneum.

Mesothelioma can be either benign or malignant. Benign mesothelioma may occur wherever there is mesothelium, is localized, and does not invade nearby tissues. It may cause problems because of a mass effect with compression or blockage of adjacent structures but can usually be managed by surgical removal. Unlike malignant mesothelioma, benign mesothelioma has no association with asbestos exposure.

Malignant mesothelioma is a cancerous tumor that is closely correlated to asbestos exposure. Most malignant mesothelioma occurs in the pleura (65-70%) but may also arise in the peritoneum (25%), the ovaries and scrotum, or the pericardium. All forms of mesothelioma have a very poor prognosis (outlook), and are usually rapidly fatal. Asbestos manufacturers and their insurers have been aware of the dangers associated with asbestos since the 1930s. However these groups have not only failed to protect workers and the public, but have conspired to prevent the health risks of asbestos from becoming widely known.