Mesothelioma Cell Types

A mesothelioma patient’s treatment options and prognosis are directly affected by the different types of mesothelioma cells. The three mesothelioma cell types are epithelioid, biphasic and sarcomatoid.

There are a number of factors that allow a doctor to diagnose the type of mesothelioma that you have and one of them is cell type. Not only will cell type assist in identifying the type of mesothelioma that is affecting you, but it also will help a doctor determine the best treatment and your overall prognosis.

What are the Mesothelioma Cell Types?

Epithelial Mesothelioma Cells

The most common type of mesothelioma cells are epithelial cells. When you are diagnosed with mesothelioma, there is a 50-70 percent chance that the mesothelioma will be made up of epithelial cells. If your mesothelioma is made up of epithelial cells, then the prognosis and treatment options usually are favorable. This type of mesothelioma is the most treatable.

Biphasic Cells

Biphasic cells are the second most common type of mesothelioma cancer cells. They are a combination of epithelial and sarcomatoid mesothelioma cells. Since epithelial cells are treatable, it is better for the mesothelioma patient’s prognosis if they have more epithelial cells in their mesothelioma tumor. If there are more sarcomatoid cells than epithelial cells, then the prognosis is not as good and the treatment options will be limited.

Sarcomatoid Mesothelioma Cells

The least common type of mesothelioma cells are sarcomatoid cells. These types of cells have the worst prognosis because they metastasize so quickly in the body. Treatment options are minimal once mesothelioma spreads throughout the body.

What is Histology and How Is It Used To Diagnose Mesothelioma Cell Types?

A physician will use a branch of biology called histology to diagnose what type of cells make up a patient’s mesothelioma. By looking at mesothelioma cells at a microscopic level, doctors can study the cellular composition of the tissue and determine the type of mesothelioma cells that are present in the patient. Not only is histology used in identifying mesothelioma cell types, but it also is used to identify other types of cancer cells.

Tissue and fluid samples are taken from areas where physicians believe there may be mesothelioma tumors. Generally, a medical procedure called a biopsy is how a physician will obtain the fluid and tissue samples that are then viewed under a microscope.

Diagnosing mesothelioma is very difficult because mesothelioma cells resemble many other types of cancer cells. Tissue and fluid samples require additional testing to determine whether they are mesothelioma cancer cells. A physician will test the proteins and antibodies to determine the type of cancer cells that may be present in a patient.

A patient must be proactive in explaining to their physician whether they have been exposed to asbestos in the past, including their prior work occupations. If a physician knows that a patient has been exposed to asbestos, then the histology will take this information into account so your cancer is not overlooked or misdiagnosed as mesothelioma.

What is the Mesothelioma Cellular Makeup?

To understand the cellular make-up of mesothelioma, you need to understand the types of tissue it affects. There are four different types of tissue in the body:

  • Muscle Tissue
  • Connective Tissue
  • Nervous Tissue
  • Epithelium

The epithelium is a type of tissue that creates linings for organs and cavities throughout the body. It is in these linings and cavities where mesothelioma cancer cells form. This does not mean that every time cancer found in the epithelium is mesothelioma. There are many other types of cancer that can form in the epithelium. A high majority of all cancers impact epithelial cells.

Asbestos fibers are inhaled or consumed and lodge in the lining of organs and cavities. The mesothelium is a type of epithelial tissue that lines the lungs, stomach and heart, lubricating them so they can function properly. Asbestos fibers can negatively impact these cells and mutate them into mesothelioma.

What is Epithelioid Mesothelioma?

This is the most common cellular type of mesothelioma, accounting for almost 70 percent of all mesothelioma cases. It is called epithelioid mesothelioma because epithelial cells mutate into cancerous cells. Although mesothelioma is difficult to treat, this is the most treatable forms.

Here are some of the common features of epithelioid mesothelioma:

  • The cell shape is elongated and can be clearly defined.
  • The epithelial cells tend to group together.
  • Patients who are diagnosed with epithelioid mesothelioma have the best prognosis.

What is Sarcomatoid Mesothelioma?

The rarest type of mesothelioma cell type is sarcomatoid mesothelioma, accounting for less than 15 percent of all mesothelioma cases. Unfortunately, the prognosis for mesothelioma patients diagnosed with sarcomatoid mesothelioma cancer cells is not very good because these types of mesothelioma cells spread extremely fast.


  • The cellular shape is irregular.
  • The cells overlap one another.
  • The cancer spreads very fast.
  • Those diagnosed with these types of mesothelioma cells have a poor prognosis.

What is Biphasic Mesothelioma?

When mesothelioma contains both epithelioid and sarcomatoid cell types it is called biphasic mesothelioma. The number of epithelioid cells or sarcomatoid cells will determine how the biphasic mesothelioma will react. If there are more epithelioid cells, then the tumor will metastasize quicker in one area of the body and will not readily spread. If there are more sarcomatoid cells, then the tumor will metastasize quicker throughout the body. The prognosis and characteristics of biphasic mesothelioma really depend upon the ratio of epithelioid cells to sarcomatoid cells. The prognosis for those with biphasic mesothelioma can be very positive if the tumor is made up of mostly epithelioid cells.

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