What Are the Major Types of Mesothelioma Cancer Cells?
When mutated, cancerous cells develop in the lining of the abdomen, lungs, or heart — called the mesothelium — they are called malignant mesothelioma cells.
There are three main mesothelioma cell types:
- Epithelioid cells: Most mesothelioma tumors are made up of epithelioid cells. This cell type is the easiest to treat.
- Sarcomatoid cells: These rare cell types are recognized by their large size and spindle shape. It is the hardest cell type to treat.
- Biphasic tumors: Biphasic tumors contain both epithelioid and sarcomatoid cells. Which cell type is dominant will determine how fast the tumors spread and respond to treatment.
Researchers are still trying to understand how and different mesothelioma cell types come about, but they know that these cells follow similar growth and division patterns to other cancer cells.
It is believed that asbestos exposure is the cause of these mutations. When asbestos fibers get into the lung, they begin to slowly move within the body. When they reach lung or peritoneal surface, they irritate healthy cells, eventually causing scar tissue and cancerous cells to form.
Each mesothelioma cell type responds differently to specific treatments, so correctly identifying the cell is key to effective treatment. For instance, a combination of surgery, chemotherapy, and radiation (called multimodal treatment) is the most common recommendation for epithelioid cells. Surgery and chemotherapy are frequently used for sarcomatoid cells.
Quick Facts About Mesothelioma Cell Types
- Epithelioid cells make up more than half of mesothelioma diagnoses and have a better prognosis (the expected outlook of the disease) than the other cell types, according to the American Cancer Society (ACS).
- The ACS states that sarcomatoid cells account for 10-20% of mesothelioma cases.
- Biphasic tumors make up the remainder of cases (20-30%), according to the ACS.
- The National Cancer Institute (NCI) notes that mesothelioma cell types can be identified under the microscope as tissue (pathology) or as cells within a fluid (cytology).