Peritoneal mesothelioma cancer affects the lining of the organs of the abdomen. This is the second most commonly occurring form of mesothelioma. Peritoneal mesothelioma accounts for between 200 and 400 cases of mesothelioma each year in the Unites States. Peritoneal mesothelioma is less understood than the more commonly occurring pleural mesothelioma, which affects the lining of the lungs; however, researchers have reached a general consensus on how this form of mesothelioma is developed.

As with other forms of mesothelioma peritoneal mesothelioma is caused by asbestos fiber lodged in the lining of organs, in this case the lining of the abdomen or peritoneum. Most experts believe that these asbestos fibers end up in the this lining by being ingested with food or drinks. It was not uncommon for asbestos fibers to cloud the air of mining facilities or asbestos processing plants, making it very easy to see how a worker could have possibly ingested these harmful fibers.

Asbestos fibers that are embedded in the peritoneum cause reoccurring inflammation of the affected areas and can eventually lead to the development of mesothelioma.