Peritoneal Mesothelioma Not Caused by Asbestos Malignant peritoneal mesothelioma develops in the abdominal lining. It is less frequent than the pleural variant and more women are affected than men. The symptoms of peritoneal mesothelioma may be vague, like abdominal discomfort, weight loss, constipation, or diarrhoea. A specialist in mesothelioma may