Among all mesothelioma diagnoses, pericardial mesothelioma only accounts for one to six percent, and is therefore the rarest kind of this particular form of cancer. 'Pericardial' is derived from pericardium, which is the Latin expression for a thin lining, often also referred to as a sac, that embeds the heart and functions like a membrane. When cancer cells start to develop in an uncontrolled fashion in the pericardium, the condition is called pericardial mesothelioma. The tumors that grow a...