Mesothelioma (pronounced mee-so-thee-lee-oma) is a very rare cancer but when it does occur there is usually a past contact with asbestos. It is a type of cancer of the thin membrane that lines the chest called the the mesothelium.
Mesotheliomas are uncommon cancers.
Mesothelioma of the lining of the lungs (pleural mesothelioma) is much more common than mesothelioma in the peritoneum (the membrane which lines the abdomen).