Peritoneal mesothelioma is a kind of mesothelioma that takes place in 10% to 20% of all the mesothelioma cases. This kind of mesothelioma is progressed into peritoneum which is the actual protective cover around the abdominal cavity and the organs. With peritoneal mesothelioma, the peritoneum will become cancerous by nature as a result of speedy expansion of cancerous cells.