Mesothelioma is a type of cancer affecting the cells of mesothelial lining in the chest and abdomen. Mesothelioma is rare, though it appears to be on the rise. Approximately 2,000 to 3,000 new cases of mesothelioma are diagnosed each year in the United States alone. Symptoms for both types of mesothelioma are not specific only to this disease, and often go undiagnosed or misdiagnosed for a significant amount of time. Difficulty breathing, abdominal and chest pain, and fever can all be attributed to other causes, so this cancer has time to advance fairly fair before diagnosis usually occurs. Due to the difficulty in diagnosis of mesothelioma, survival time after diagnosis is estimated at about a year.

There are two main types of mesothelioma. The first type, pleural mesothelioma, spreads within the chest cavity, and sometimes involves the lungs. This type or cancer can metastasize into any of the bodys organs, including the brain.

Metastasis occurs more often than previously thought, and signals the diseases progression. Symptoms of pleural mesothelioma include persistent pain in the chest and severe difficulty breathing caused by pleural effusion, or an accumulation of fluid in the pleural lining Cough, weight loss, and fever are also common symptoms. Survival time for this type of mesothelioma is better than that of peritoneal mesothelioma. The median survival time is 17 months, with ten percent of patients living for three years after diagnosis.

The second type of mesothelioma is peritoneal mesothelioma. This cancer invades the abdominal cavity, the liver, spleen, and sometimes the bowel. Predominant symptoms of peritoneal mesothelioma include persistent pain the region as well as a swollen abdomen, both due to the accumulation of fluid in the abdomen and affected organs. Other symptoms include nausea, vomiting, and swelling of feet, fever, and difficulty moving the bowels. The prognosis for peritoneal mesothelioma is worse than that of pleural mesothelioma, with a median survival time of only ten months past diagnosis.

Mesothelioma takes two rarer forms. Benign mesothelioma is a cancer of the mesothelioma of the peritoneum. The peritoneum is the lining of the major organs in the chest and abdomen. It is difficult to diagnose, and appears more frequently in young women. Mesothelioma of the pericardium is a very rare cardiac cancer. Mesothelioma can also occur in the ovaries and scrotum. The prognosis for these unusual kinds of mesothelioma, with the exception of benign mesothelioma, is very poor.

The progression of mesothelioma is broken down to four stages. These stages provide a baseline to predict how far along the cancer has spread. Staging is based on x-rays, CT scans, and MRI imaging. Treatment decisions and prognosis depend upon the stage of the mesothelioma, as well as the kind if mesothelioma. In the first stage, mesothelioma is present in the pleura, lung, pericardium, or diaphragm, and is localized to one side of the body. Mesothelioma invades the chest wall or the esophagus during the second stage. The second stage may also see cancer in the heart, both sides of the pleura, or the lymph nodes in the chest. The third stage involves penetration through the diaphragm and into the peritoneum, and sees cancer spread to more distant lymph nodes. The fourth and final stage occurs when tests provide evidence of metastases in distant organs. Within the fourth stage, the mesothelioma spreads through the bloodstream to these new sights.

Mesothelioma is most often caused by exposure to Asbestos. Asbestos was frequently used for insulation in homes or businesses. Schools, factories, and military buildings have also been found to contain asbestos. Radiation from thorium dioxide may also cause mesothelioma. This material was once used for x-rays, though was not widely used for long. Zeolite, a silicate material related to asbestos, may also cause mesothelioma. Cases of Zeolite-induced mesothelioma centralize in the Anatoli region of Turkey.