Cancer that begins in the cells of the mesothelium is called mesothelioma. A malignant tumor is a group of cancerous cells that can invade and damage nearby tissues. It can also spread, or metastasize, to other parts of the body.
Two layers make up the mesothelium membrane. The inner layer covers several organs, like the lungs, stomach, and heart. The outer layer constitutes a bag all around the same inner layer. There is a small amount of fluid between the two layers, which allows organs to move easily.
Different types of mesothelioma
The mesothelium is given different names based on its location in the body. For instance, the mesothelium that forms a protective cushion around the lungs is referred to as the pleura. The inner layer of the pleura that wraps around the lungs is named visceral pleura. The outer layer of the pleura, which lines the inside of the chest, is named the parietal pleura.
Another example is the mesothelium that wraps around the organs that are abdominal and lines the walls of abdomen and pelvis; this is named the peritoneum. Peritoneum at its inner layer, which envelops and supports most of the internal abdominal organs, is referred to as the visceral peritoneum. Lastly, the outer layer of the peritoneum, which lines the walls of the abdomen and pelvis, is named the parietal peritoneum.
Mesothelial cells make up the mesothelium. Sometimes, these cells change in a way that makes their growth or behavior abnormal. This can lead to the formation of benign tumors, like fibrous pleural tumors or multicystic mesothelioma. But in other cases, modifications to mesothelial cells can be the cause of malignant mesothelioma.
A rare cancer
Mesothelioma is a cancer that is not very common. It typically develops in the pleura. This form of mesothelioma, which makes up 70 to 80 percent of all mesothelioma cases, is then referred to as pleural mesothelioma. However, mesothelioma can also develop in the peritoneum and this type of cancer accounts for roughly 25% of all mesothelioma cases and is known as peritoneal mesothelioma.
In addition, there are rarer types of mesothelioma like pericardial mesothelioma which affects the membrane surrounding the heart (pericardium) or tunica vaginalis mesothelioma, which affects the outer lining of the testicles.