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Mesothelioma Histology

Mesothelioma histology is a way to describe the cancer by the types of cells involved. While the location of the cancer is important, the type of cells involved is significant as well. When physicians know the types of cells involved, they are able to personalize the treatment plan.

The body is made up of cells, and there are more than 300 different categories. Doctors use a variety of means to determine the cell types involved in the disease, including diagnostic testing and biopsies.

This is crucial because, while the cell types do not change symptoms, some clinical trials and treatments may be targeted to certain cell types. When it comes to these cancer cells, there are three predominate kinds that offer different challenges for treatment.

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Epithelial Cells

These cells look uniform in shape and arrangement under a microscope. They have a central nucleus, are cube-shaped and look like they’re in neat rows. Epithelial cells make up the body’s membranous tissue, including the mesothelium, which is damaged during asbestos cancer. There are several varieties and subtypes of epithelial cells including papillary cells, which make up well-differentiated papillary mesothelioma (WDPM).

Epithelial cells are the most common asbestos-cancer cell type, accounting for up to 75 percent of all cases. These types of cells are known to respond favorably to treatment, including surgery.

Sarcomatoid Cells

As the least common cell type in this disease, sarcomatoid cells account for up to 20 percent of diagnoses. Most sarcomatoid tumors can be found in the pleura, or protective covering around the lungs. In fact, up to 20 percent of all pleural mesothelioma cases involve sarcomatoid tumors. These types of cells are also challenging to diagnose because they mimic other types of cancer cells. There are a wide variety of sarcomatoid cells.

Sarcomatoid cells look stretched and rod-shaped. Instead of looking neat like epithelial cells, these look disorganized and haphazard under a microscope. Sarcomatoid cells can be more treatment resistant than other types of disease cells. While chemotherapy has offered limited success with this cell type, surgery to remove them is difficult. That’s because sarcomatoid tumors are known to be rigid.

Biphasic Cells

These cells are a combination of epithelial and sarcomatoid cells and are known to be the second most common type of asbestos-cancer cells. Under the microscope, biphasic cells are disorganized with some epithelial cells and some sarcomatoid cells mixed together in no particular order.

Up to 35 percent of patients are diagnosed with biphasic diseased cells. Also called a mixed-cell type, biphasic cells are more commonly seen with a pleural mesothelioma diagnosis. Biphasic cells are sometimes difficult to diagnose because small biopsies may miss the small distinctions in the cells. For this reason, it is important that a large biopsy be taken. Also, it is important to have a skilled asbestos physician who understands the differences in these cell types and their link to asbestos.


Hammer, Samuel, P. “Macroscopic, Histologic, Histochemical, Immunohistochemical And Ultrastructural Features Of Mesothelioma.” Retrieved from http://www.ultrapath.org/oldsite/uscap/uscap05/meso1.pdf

Roy, Abhik, et al. “Sarcomatoid Mesothelioma in a Patient with Asbestos Exposure.” Retrieved from http://jdc.jefferson.edu/cgi/viewcontent.cgi?article=1227&context=tmf