Mesothelioma cancer develops in the lining of the lungs, heart or stomach. (And its name derives from the scientific term for this coating – the mesothelium). Like most cancers, mesothelioma begins as a single, fairly small nodule. Progressively, the tumors are expanded by the mesothelium’s surface and do so in spiral form. By the time cancer develops completely, it spreads extremely rapidly to other organs.
The progression of mesothelioma cancer is measured in stages ranging from one to four scales. Stage I is the least severe, while stage IV is the most severe. Mesothelioma cancer has very mild symptoms in its early stages and that is why most patients who are diagnosed are in stage III or IV. Surviving Mesothelioma is possible if treated early.
What are the types of mesothelioma?
Four types of mesothelioma are known. Each one indicates that the disease is growing in a specific part of the body.
- Pleural mesothelioma develops in the mesothelium that lines the lungs.
- Peritoneal mesothelioma grows in the mesothelium that lines the stomach.
- Pericardial mesothelioma progresses in the mesothelium that lines the heart.
- Testicular mesothelioma matures in the lining of the testicles.
More than 75% of patients diagnosed with mesothelioma suffer from the pleural type. Peritoneal mesothelioma is the second most common and represents between 10 and 20 percent of cases, while pericardial and testicular mesothelioma accounts for only 1 percent of diagnoses. Mesothelioma cancer can also be classified by cell type.
There are three types of cells that line the mesothelium and mesothelioma cancer can develop in any of them. The types of cellular mesothelioma include:
- Epithelial mesothelioma which occurs in small cells of the membrane, much like a tube.
- Mesothelioma of the sarcomatoid develops in the cells of the long membranes – similar to an axis.
- Biphasic mesothelioma grows in the epithelial and sarcomatoid cells.
What causes mesothelioma cancer?
Exposure to asbestos is the main reason why people get mesothelioma. Almost 80 percent of cases are related to occupational exposures. The vast majority of other cases are associated with exposure to the mineral in homes or some type of environmental exposure.