Mesothelioma

Mesothelioma is a form of cancer that is almost always caused by previous exposure to asbestos. In this disease, malignant cells develop in the mesothelium, a protective lining that covers most of the body's internal organs. Its most common site is the pleura (outer lining of the lungs and internal chest wall), but it may also occur in the peritoneum (the lining of the abdominal cavity), the heart, the pericardium (a sac that surrounds the heart) or tunica vaginalis.

The mesothelium that covers the internal organs is called the visceral mesothelium, while the layer that covers the body wall is called parietal mesothelium.

Mesothelium tissue also surrounds the male internal reproductive organs and covers the internal reproductive organs in women.

Mesothelioma is an aggressive cancer of this mesothelium, in which cells of the mesothelium become abnormal and divide uncontrollably and without order. They can invade and damage nearby tissues and organs. Most cases of mesothelioma begin in the thoracic cavity (pleura) or the abdominal cavity (peritoneum).

Approximately 2,000 to 3,000 cases of mesothelioma are diagnosed each year in the United States, comprising around 3 percent of all cancer diagnoses. This cancer occurs more frequently in men than in women, about four times more frequent. All forms of mesothelioma, except for benign mesothelioma, are invariably fatal. The prognosis for mesothelioma is almost always poor and most studies report a median survival of less than one year, but the prognosis really depends on how early it is diagnosed and aggressively it is treated.

Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles, or they have been exposed to asbestos dust and fiber in other ways. Washing the clothes of a family member who worked with asbestos can also put a person at risk for developing mesothelioma.

Unlike lung cancer, there is no association between mesothelioma and smoking. Compensation via asbestos funds or lawsuits is an important issue in mesothelioma (see asbestos and the law).

The symptoms of mesothelioma include shortness of breath due to pleural effusion (fluid between the lung and the chest wall) or chest wall pain, and general symptoms such as weight loss.

The diagnosis may be suspected with chest X-ray and CT scan, and is confirmed with a biopsy (tissue sample) and microscopic examination. A thoracoscopy (inserting a tube with a camera into the chest) can be used to take biopsies. It allows the introduction of substances such as talc to obliterate the pleural space (called pleurodesis), which prevents more fluid from accumulating and pressing on the lung.

Despite treatment with chemotherapy, radiation therapy or sometimes surgery, the disease carries a poor prognosis. Research about screening tests for the early detection of mesothelioma is ongoing.

http://en.wikipedia.org/wiki/Mesothelioma

http://www.asbestos.com/