Nearly 75 percent of mesotheliomas are initiated in the chest and are called pleural mesotheliomas. Pleural mesothelioma is the most common form of this devastating disease. This occurs when asbestos fibers enter the pleura, which is the membrane that covers the lungs, and results in the formation of malignant cells. The people most at risk of developing this rare form of cancer are construction workers who have been exposed to asbestos fibers for extended periods of time, their families, who are exposed to the asbestos fibers that collect on the clothes of the workers, and people who live or work in buildings that are insulated with asbestos material.

The risk of developing malignant pleural mesothelioma depends on several factors, such as the length of time the person has been exposed, and the nature of the asbestos fibers involved as well as the different kinds of industries. Other factors can also contribute to onset of pleural mesothelioma.

The symptoms at the initial stage can resemble that of pneumonia. When malignant mesothelioma originates in the pleural cavity, the first symptom may be a mild pain in the chest or back. When malignant pleural mesothelioma spreads, organs and tissues in the immediate area can be affected. It grows into the chest wall, muscles and ribs. The pain changes from mild, general and episodic to severe, localized and chronic as the disease progresses. Severe pain may not respond to oral doses, intravenous infusions, or intramuscular injections of analgesics or narcotics.

There are at least two other forms of mesothelioma, but pleural mesothelioma responds best to treatment. Unfortunately, the fatality rate remains high. However, extensive research is going on to alleviate the pain of mesothelioma sufferers, develop a vaccine, and treat the progression of the cancer.