Mesothelioma is a deadly cancer that is almost always the result of asbestos exposure. The longer a person has been exposed to asbestos, the greater his or her chances are of developing this dangerous disease. Once you are diagnosed with mesothelioma, doctors will try to identify the cell type so that they can better estimate your life expectancy as well as devise the best treatment plan for you.
Mesothelioma attacks the special cells that line the cavities and organs of your body, called the mesothelium. Typically, this cancer is categorized based on the location of the initial tumor growth. For instance, if your cancer starts in your abdomen, it is called peritoneal mesothelioma. However, doctors will also try to identify the cell type present in your tumor.
Mesothelioma cells come in two different forms, epithelioid and sarcomatoid. Epithelioid cells make up 50-70% of mesothelioma cases, and they are generally more easily treated than sarcomatoid. Under a microscope, they appear cubic or tubular in shape with a distinct nucleus. On the other hand, sarcomatoid cells are less uniform with a less distinct nucleus. They are more fibrous, and they tend to appear in oval or spindle shapes.
Interestingly, epithelioid and sarcomatoid cells are easily confused with other types of cancer. Therefore, it can sometimes be difficult for a doctor to identify if you have mesothelioma or a type of cancer called sarcomatoid carcinoma or sarcoma, or epithelioid mesothelioma rather than adenocarcinoma.
The last type of mesothelioma is called biphasic. In fact, this is not its own cell type, but actually a mix of the two other types. These tumors will have mixed chunks of either epithelioid or sarcomatoid cells. Although biphasic tumors are easier to identify as mesothelioma than strictly one or the other, this is actually the most deadly form of this cancer.