Diffuse malignant mesothelioma (DMM) is a rare aggressive cancer arising from the mesothelial cells that line the body cavities. Typically, in its later stages the tumor infiltrates the affected serous membrane diffusely and frequently metastasizes to at least a limited extent. Most commonly developing in the pleura (around 70% overall), with most of the remaining cases originating in peritoneum, the malignant tumor occupies a special position among work-related asbestos cancers on account of its predominant association with the carcinogen. Though the neoplasm has yielded little to therapeutic assault, accurate diagnosis is essential because of its sentinel role in relation to the carcinogenic effects of asbestos. Other tumors of putative mesothelial origin, including localized fibrous mesothelioma, well-differentiated papillary mesothelioma, benign cystic mesothelioma, adenomatoid tumor, and primary serous cancers of the peritoneum have not been reported to have a significant association with asbestos.
Up to the 1950s, the status of DMM as an entity was sometimes regarded with skepticism, it being maintained that many putative cancers of this type originated elsewhere in the body and only secondarily involved serous membrane [Robertson, 1924; Willis, 19521. For a time, this suspicion fostered the belief that definite diagnosis could only be made at autopsy, following a meticulous search for an alternative primary source of cancer, and that even then, an occult primary tumor might be easily missed. In the older literature dating back to the second half of the nineteenth century, malignant tumors resembling DMM were described by such designations as endothelioma, endothelial cancer, pleural cancer and pleural sarcoma [Robertson, 19241, but the details reported often do not permit accurate classification of these neoplasms based on current criteria. Introduction of the term mesothelioma has been attributed to Adami in 1909 [Robertson, 19241. Widespread acceptance of the existence of DMM as a valid entity grew out of