Mesothelioma Cancer - Overview

Mesothelioma is a rare type of cancer that develops in the mesothelial cells that lines many organs and body cavities. The mesothelium (composed of mesothelial cells) is the membrane that lines three of the body's cavities, and depending on what cavity it lines it is given a specific name: the thoracic cavity (pleura), abdominal cavity (peritoneum), and the heart sac (pericardium).

Mesothelioma is a rare cancer that can develop in the mesothelium of the thoracic cavity in the lungs.
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.