What is mesothelioma?

Mesothelioma is a very rare cancer of the lining of the lung (pleural), stomach (peritoneum), heart (pericardial) or testicles (tunica vaginalis). Doctors call this lining the serosal membrane which is a very thin membrane covering these areas within the body. Mesothelioma is not lung cancer. Smoking does not cause mesothelioma. In North America, the overwhelming single cause of mesothelioma is exposure to asbestos. Doctors consider mesothelioma a "signal" tumor of asbestos exposure due to the strength of the association between asbestos and this type of cancer. There is a latency period between the time of first exposure to asbestos and clinical diagnosis of mesothelioma. This latency period is anywhere from as low as 10 years (rare) to over 60 years. In other words, people exposed to asbestos many decades ago may not get mesothelioma until now.