The mesothelium is a specific type of cell grouping which helps to form the membranous protective covering or lining for some organs.  These types of membranes are the body’s serous membranes, or serosae, and provide the sacs that enclose the heart, lungs, and abdominal areas.  This type of membrane is responsible for producing the lubricating agent which allows the body to enact the subtle movements necessary for proper organ functioning.

“Mesothelioma” is the name for a relatively rare cancer which attacks areas of the body’s mesothelium.  There are several different areas of the body that are covered by mesothelium: the heart, which is enclosed by the pericardium; the lungs, which are enclosed by the pleura; and the abdominal covering or peritoneum.  Therefore, mesothelioma can be further specified as pericardial, pleural, or peritoneal, depending on the afflicted area or areas.  Most mesotheliomas originate in the pleural mesothelium, but can spread to adjacent organs and tissues.  Additionally, cancer has the ability to spread from one site to another.  When cancer spreads, it is said to metastasize; this secondary cancer is referred to as a metastasis.