You have certainly heard of the term mesothelioma. It derives from mesothelium, which is very thin covering that works like a membrane and protects a number of internal organs including the lungs and the heart. Mesothelioma is a rare form of cancer that starts in the mesothelium. Despite all the advances in cancer research, this malignant condition is still not curable.

There are two different forms of the mesothelium: the parietal mesothelium and the visceral mesothelium. The visceral mesothelium is the mesothelial tissue that is located in the abdominal cavity.The parietal mesothelium is the membrane that surrounds the walls and the lungs of the chest cavity.


The Mesothelium (image courtesy of mesotheliomas.co.cc)

Origin: Mesothelium comes from the developing mesoderm cell layer which lines up the coelom in the embryo. It grows into the layer cells which protect and cover the majority of the inner organs of the body. The layer of mesothelial cells grow in cell cultures, featuring the distinctive "cobblestone" form.

Structure: The mesothelium is shaped as a monolayer of compressed squamous similar to epithelial cells on top of a thin cellar membrane connected through connective tissue. The cuboidal mesothelial cells are present in the peritoneal area of the diaphragm, located on top the lymphatic lacunae as well as the milky spots of the omentum. The luminal exterior is enclosed up with microvilli. The serosal fluid and proteins are encapsulated by the microvilli which form a smooth surface for internal organs.

Function: The mesothelium is made up of a widespread monolayer of distinctive cells which line up the body's internal organs and cavities.

The major function of these cells is to create a lubricating liquid that is found between the layers, a protective and non-adhesive substance ensuring a smooth intracoelomic movement. Role in mesothelioma Mesothelioma or otherwise known as the cancer of the mesothelium, is a disease in which cells of the mesothelium start to grow irregularly and furthermore divide with no order or control. They can damage and invade areas in close proximity. The cancer cells, as the disease progresses, start to spread further inside the human body. Nearly all cases of mesothelioma start in the peritoneum or pleura. The single proved cause for mesothelioma is asbestos exposure.

Mesothelioma has a long latency period. It may take up to numerous decades before the disease shows any signs or symptoms. This does have a negative impact on the early detection. In most cases a mesothelioma diagnosis is made when the disease has already progressed into an advanced stage.