Mesothelioma

Mesothelioma is a rare form of cancer in which malignant cells are found in the mesothelium. When it occurs, the cells of the mesothelium become abnormal and divide without control or order. They can invade and damage nearby tissues and organs. Cancer cells can also spread to other parts of the body. 

Mesothelium is a membrane that covers and protects most of the internal organs of the body. A layer of specialized cells called mesothelial cells lines the chest cavity, abdominal cavity, and the cavity around the heart. These cells also cover the outer surface of most internal organs. The tissue formed by these cells is called mesothelium. The mesothelium of chest is called pleura, of the abdomen is peritoneum and of the pericardial cavity, i.e the sac-like space around the heart, is called pericardium. 

Most cases of mesothelioma begin in the pleura or peritoneum. The fibrous sheets, pleura helps to protect the lungs. There are 2 pleura and they can be called pleural membranes. Pleural space is the gap between them and they produce a lubricating fluid that fills the gap. This helps the lungs to move smoothly in the chest when they are inflating and deflating as we breathe. Peritoneal or Peritoneum is a smooth membrane, which lines the cavity of the abdomen (stomach). It helps to protect the contents of the abdomen. It also produces a lubricating fluid which helps the organs to move smoothly inside the abdomen as we move around.