Types of Mesothelioma

There are three principal variations of mesothelioma, based on where in the human body it develops. There are also three categories of malignant cells associated with the disease: cell type dictates the type of chemotherapy that is appropriate for treatment. In this section we’ll review the basic medical facts that define a case of mesothelioma.

The only known cause for mesothelioma is the asbestos fiber. Asbestos is made up of these tough, flexible and tiny fibers that are invisible to the human eye. They impact humans when they make their way inside the body, which occurs when you either inhale them or ingest them inadvertently.

They are small enough that you wouldn’t know about the intake; they could be present in a cloud of dust caused by a deteriorating asbestos product. That cloud of dust could send fibers into your lungs, or allow them to float down on a sandwich at the work site.

Mesothelioma is a form of cancer that develops in the mesothelium, which is a membrane that lines many areas within the body. It wraps around the outer surfaces of both lungs as well as the outer surface of the heart. In addition, it lines the walls of both the chest cavity and the abdominal cavity.

Asbestos fibers become embedded in the mesothelium, almost always in one of three areas: the portion that forms the outer lining of the lungs, the membrane wrapped around the heart, or the lining of the abdominal cavity. These three areas of the anatomy define the three types of cancerous mesothelioma. There is also a benign form of the disease, a rare occurrence that may be found in any of the three areas.

pleural mesothelioma

Pleural mesothelioma is cancer that develops in the lining of the lungs. Two thirds or more of all mesothelioma cases are pleural; the terms “mesothelioma lung cancer” and “asbestos lung cancer” are non-medical terms for this version of the disease. Often pleural mesothelioma is misdiagnosed because initial symptoms are usually a persistent cough, shortness of breath and tightness in the chest – symptoms that are found in much more common diseases such as pneumonia, emphysema and chronic bronchitis.

Peritoneal Mesothelioma

Twenty to thirty percent of all mesothelioma cases develop in the peritoneum, the membrane that lines the abdominal cavity. This version is called peritoneal mesothelioma; it seems to have a latency period of twenty to thirty years, shorter than the thirty to forty years attributed to pleural mesothelioma. No one is quite sure how asbestos fibers make their way to the abdominal cavity; the prevalent theory is that they are ingested and work their way through the wall of the digestive tract.

Pericardial Mesothelioma

The pericardium is the membrane formed into a sac that surrounds the heart. Pericardial mesothelioma is a rare version of the disease, developing in perhaps five percent of all cases. The theory on development of this disease is that asbestos fibers are broken into pieces in the lungs, small enough that they can be carried through the bloodstream to the heart. There they lodge in the lining of the heart and develop mesothelioma in much the same fashion as asbestos fibers cause the more common pleural mesothelioma.

Mesothelioma Cells

The cancer cells that develop as the result of asbestos fibers in the mesothelium are of two varieties, but manifest themselves in three different ways. Epithelioid cancer cells are the most common variety for mesothelioma cases of all types. The second and less common malignancy in mesothelioma is the sarcomatoid cell. This cell type is usually associated with peritoneal mesothelioma. The third category of cell configuration for mesothelioma is biphasic, a rare form of the disease that consists of both epithelioid and sarcomatoid cells.

Different cell types respond to different chemotherapy approaches. One cell might be best dealt with by attempting to block nourishment to the malignant area. Another might be more responsive to a type of enzyme associated with the immune system that will attack the malignant cell. Doctors are constantly experimenting with combinations of drugs to develop the most potent methods of stopping cancerous growth, and eliminating the existing cells.