Malignant mesothelioma

Malignant mesothelioma is an aggressive tumor that is increasing in incidence all over the world, even though its incidence has leveled off in the United States. Asbestos exposure is considered the main risk factor for mesothelioma. Some experts believe that exposure to simian virus 40 may also play a role. Pleural mesothelioma accounts for 90% of all tumors, although mesotheliomas can occur in other serosal surfaces. Histopathology, immunohistochemistry, and sometimes electron microscopy are required to distinguish mesothelioma from other tumors involving the pleura. Performance status and sarcomatoid histology are among the most important prognostic factors. Median survival for pleural mesothelioma is 12 months from diagnosis. Recent data have demonstrated the benefits of chemotherapy in patients with good performance status. The role of aggressive surgery, such as extrapleural pneumonectomy, remains ill defined, though it should be considered in early-stage disease. Multimodality regimens are being evaluated to improve upon the current outcome of these patients. With greater understanding of the molecular mechanisms underlying the pathogenesis of mesothelioma, there is hope of developing novel agents that are more effective.