Malignant mesothelioma is a cancer of the cells that make up the lining around the outside of the lungs and inside of the ribs (pleura), or around the abdominal organs (peritoneum). There are also rare instances of malignant mesotheliomas in other areas of the body.

Malignant mesothelioma, a rare form of cancer caused by exposure to asbestos, is a disease in which cancer cells are found in the sac lining the chest, the lining of the abdominal cavity, or the lining around the heart. Malignant mesothelioma is an uncommon cancer that is difficult to diagnose and poorly responsive to therapy. Malignant mesothelioma is the most serious of all asbestos-related diseases.

Pleural mesothelioma is a cancer of the cells that make up the pleura or lining around the outside of the lungs and inside of the ribs. The only known cause of mesothelioma is previous exposure to asbestos fibers, including chrysotile, amosite or crocidolite. This exposure is likely to have happened twenty or more years before the mesothelioma becomes evident, since it takes many years for the disease to "incubate." It is the most common type of mesothelioma, accounting for about 75% of all cases.

Peritoneal Mesothelioma, or abdominal mesothelioma is found in the abdomen in a thin membrane called the peritoneum. Peritoneal mesothelioma is a rapidly fatal primary peritoneal malignancy with an average survival time of less than 1 year, mainly because there is no effective treatment. Peritoneal mesothelioma is a tumor of this periotneal membrane. Symptoms of peritoneal mesothelioma include abdominal swelling, loss of appetite, and weakness. The only known cause to this disease is exposure to asbestos. Periotneal mesothelioma take years to develop, and the exposure is likely to have taken place 20 or more years ago. This type of mesothelioma is the less common and is found in less than 25% of all mesothelioma cases. Like pleural mesothelioma, peritoneal mesothelioma can be either benign or malignant.

Mesothelioma is a rare form of cancer that involves the mesothelium, or cells that line an organ, usually the lungs, abdominal organs, and heart. The most common form of mesothelioma is pleural mesothelioma, where malignant tumors form on the pleura, the sac that lines the chest cavity and protects the lungs. Other forms of mesothelioma affect the peritoneum (abdominal cavity lining) and the pericardium (lining around the heart).


Mesothelioma is usually caused by asbestos exposure. Asbestos is a fibrous mineral known to be carcinogenic. People who are exposed to asbestos fibers for just a short period of time (few weeks) or even to a small amount may be at risk. In particular, people working with asbestos and their family members or those who live with them develop mesothelioma.

There is a long latency period between initial exposure to asbestos and the development of malignant tumors. On average, 35-40 years elapse before the onset of disease.

The early symptoms of mesothelioma can resemble pneumonia, including shortness of breath, difficulty breathing, persistent cough, chest and abdominal pain. Often, there is fluid buildup between the pleura and chest cavity (called pleural effusions), which leads to dyspnea (shortness of breath) and sometimes pain. Some people may not have any symptoms.

Treatment for mesothelioma can be surgery to remove the tumors, chemotherapy, radiation, or a combination of the three.

Depending on the person’s health, time of diagnosis, and other factors, the survival rate is about four to 12 months from the onset of symptoms. However, occasionally people may live longer.

What is Mesothelioma? Mesothelioma from the (Greek meso+ thelioma, tumor of middle lining tissue) is an uncommon cancer, originating from the cells which form the membrane lining the abdominal cavity (peritoneal membrane or peritoneum) which houses the intestines, or the chest (pleural membrane or pleura) cavity housing the heart and lungs, in which the cells making up those tissues begin to grow out of control.

Mesotheliomas most often are seen in older patients, more often men that have a history of occupational exposure to asbestos, although other causes such as radiation and certain viruses have occasionally been implicated. In a proportion of cases, no asbestos exposure can be identified.

Mesotheliomas involving the lung and pleura characteristically present as progressive shortness of breath due to the thickening of the lining membrane of the lung with gradual contraction of the breathing space; often, fluid accumulates in the lung spaces as well, further interfering with breathing, Mesotheliomas involving the abdominal cavity present with digestive symptoms, and abdominal swelling due to thickening of the lining membranes of the gut, and accumulation of large amounts of fluid in the abdomen.

How serious is it ? Mesotheliomas are serious and potentially life-threatening. Survival of patients with mesothelioma is usually short if effective treatment is not found, especially those with tumors that can be shown to be growing aggressively. Because mesotheliomas have usually spread throughout the pleural or peritoneal cavity before the diagnosis is made, complete surgical removal is only rarely possible. Moreover, mesotheliomas are not as sensitive to radiation therapy or chemotherapy as are many other tumors.

How are mesotheliomas diagnosed? In all cases, the diagnosis of mesothelioma must first be unquestionably established by biopsy of affected or suspicious tissues, and by definitive microscopic examination by a trained pathologist. Biopsy almost always requires an invasive procedure such as thoracoscopy and pleural biopsy, or laparotomy or laparoscopy, The removed tissues may be treated with special biological or chemical stains which are used to help the pathologist establish a firm diagnosis. The pathologist usually also comments upon the rate of growth and biological virulence of the tumor

Second, the tumor must be staged if possible by X-ray, CAT scan, MRI or other types of scans to clarify its location within the body, and to estimate the likelihood of effective curative or palliative therapy. Staging of mesothelioma by x-ray measurements, however, is difficult and often unreliable.

How are mesotheliomas treated? A treatment plan is devised depending upon the mesothelioma type, aggressiveness, primary location, and degree of local (rarely, distant) spread. The treatment of pleural mesothelioma is difficult. Treatment with surgery, radiation therapy or chemotherapy used alone or in combination may be proposed, depending upon the potential benefits and risks of each modality. Surgery is rarely used alone, but sometimes suffices when only a small pleural patch of mesothelioma is detected, thus allowing visually complete removal of the tumor. More often, mesotheliomas of the left or right pleural cavity cannot be completely removed without taking the entire lung (pneumonectomy) on the same side as well. In such cases, radiation therapy and/or chemotherapy is given postoperatively to help eradicate any residual mesothelioma that may have escaped the surgeon.

The treatment of peritoneal mesotheliomas is even more problematic; until recently no consistent treatment was available. At our institution, peritoneal mesotheliomas have been managed in the experimental setting with combined modality treatment consisting of extensive (usually not complete) debulking surgery, followed by intraperitoneal and systemic chemotherapy followed in turn by whole abdominal radiation therapy.

Because mesotheliomas now represent less than one percent of cancers and and are infrequently seen in the practice of most community oncologists, finding the correct treatment can be very difficult. Proper management of mesotheliomas often requires evaluation at larger tertiary hospitals or Comprehensive Cancer Centers by specialists in medical, surgical and radiation oncology with experience in all aspects of the clinical care of mesothelioma patients, including the newest experimental treatments.