Malignant mesothelioma is an uncommon form of cancer and of all asbestos related diseases, the most serious. The symptoms associated with the disease make it difficult for doctors to diagnose. Often, by the time that a proper diagnosis is made, the disease has progressed to a point where patients do not respond well to treatment therapy. Malignant mesothelioma is caused almost exclusively by the inhalation of airborne asbestos particles. Another unique factor associated with the disease is that there can be a long latency period between the time of asbestos exposure and the actual manifestation of the disease in the form of malignant mesothelioma.