What Is Malignant Mesothelioma?

A layer of specialized cells called mesothelial cells lines the chest cavity, abdominal cavity, and
the cavity around your heart. These cells also cover the outer surface of most of your internal
organs. The tissue formed by these cells is called mesothelium.
The mesothelium helps protect your organs by producing a special lubricating fluid that allows
organs to move around. For example, this fluid makes it easier for the lungs to move inside the
chest during breathing. The mesothelium of the chest is called the pleura and the mesothelium of
the abdomen is known as the peritoneum. The mesothelium of the pericardial cavity (the "saclike"
space around the heart) is called the pericardium.
Tumors of the mesothelium can be benign (noncancerous) or malignant (cancerous).
A
malignant tumor of the mesothelium is called a malignant mesothelioma. Because most
mesothelial tumors are cancerous, malignant mesothelioma is often simply called mesothelioma