Neoplasm by anatomical site Malignant mesothelioma 2010-05-11T04:10:29Z SNOMEDCT_US:62064005 UMLS:C0345967 Malignant mesothelioma is a form of cancer that originates from the cells of the mesothelium, a thin tissue layer surrounding the body's internal organs. Malignant mesothelioma is almost exclusively caused by asbestos exposure, pleural mesothelioma being the most common form, affecting the lining of the lungs called the pleura. Other forms such as perioneal-, percardial- or testicular- mesothelioma are much rarer. HP:0100001