Peritoneal mesothelioma is caused,

• When asbestos fibers are ingested in water or (more rarely) food, and then migrate through the stomach or intestinal wall.
• When the asbestos fibers come in the lungs and then migrating into the peritoneum via the lymph system or the bloodstream.
• It is even possible that asbestos fibers might be present in sputum which is coughed up and then ingested.

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When asbestos fibers are ingested, they cannot be removed by the body’s immune system because of their durability. Minute fibers enter the stomach and penetrate the stomach lining. As more and more fibers penetrate this delicate organ, the cells on the exterior lining begin to mutate into cancerous mesothelioma cells. They cause chronic inflammation of cells in the lungs and develop a fibrosis that stop the peritoneum from functioning properly and protecting abdominal organs. These cells accumulate into tumors, and eventually overwhelm the peritoneum, killing off healthy stomach cells in the process. The tumors on the stomach lining grow and exert increasing pressure on surrounding organs causing agonizing pain.

Comprising approximately 25 percent of mesothelioma cases, this form of mesothelioma develops in the lining of the abdominal cavity, known as the peritoneal membrane. The collection of cells surrounds the gastrointestinal tract and provides lubrication for the stomach and intestines to move so that they may function properly. These organs must be able to move properly in order to properly digest and process food, and a failure in the peritoneum can result in severe and debilitating consequences.

You can get all the types of Mesothelioma details on this blog.