Peritoneal Mesothelioma Not Caused by Asbestos Malignant peritoneal mesothelioma develops in the lining of the abdomen. It is less frequent than pleural mesothelioma and it is more common in women than men. Symptoms of peritoneal msothelioma can be vague, such as abdominal discomfort, weight loss, constipation or diarrhoea. A mesothelioma