The type of mesothelioma cell can be significant on a patient’s prognosis and treatment plan. About 60 percent of all mesothelioma cases are epithelioid. This cell type usually has a better prognosis than sarcomatoid, which accounts for about 10–25 percent of all mesothelioma cases. The remaining 30–40 percent of cases are biphasic, meaning a patient’s tumor exhibits both epithelioid and sarcomatoid cells. A biphasic diagnosis requires at least 10 percent of each cell pattern to be present in the tumor.

Epithelioid tumors originate in the cells that line an organ, whereas sarcomatoid tumors start growing in the bone or soft tissues. Sarcomatoid cells tend to metastasize faster than epithelioid cells, making epithelioid cases generally more treatable. Most patients with epithelioid tumors undergo a multimodal treatment plan (treatment approach that combines multiple therapies, such as chemotherapy and radiation) to eradicate the cancer.

Visiting a specialist, getting a second opinion, and having a customized treatment plan are of the utmost importance when fighting mesothelioma.

It’s also important to remember that statistics are merely that: statistics. Statistics are numbers based on other patients, other circumstances, and other survival rates. And because mesothelioma is such a rare cancer, these numbers are usually stale. As a patient, attitude matters. Accepting your diagnosis doesn’t mean you must accept your doctor-given prognosis. Many mesothelioma patients have outlived their original prognosis, and treatment options continue to advance as doctors learn more about this rare disease.

Types of Mesothelioma Cells

Mesothelioma Hub | Cell Types

EpithelioidSarcomatoidBiphasic (mixed)
60% of cases10-25% of cases30-40% of cases
18-24-month median survival4-6-month median survival10-15-month median survival
Commonly found in the lungsCommonly found in the lungs and abdomenCommonly found in the lungs and abdomen

How Do I Know What Cell Type I Have?

A biopsy is the only definitive way to confirm a mesothelioma diagnosis and will inform your doctor of what cell type you have. It can also prevent misdiagnosis, as the cell type helps doctors rule out other potential malignancies.

A histopathologist (doctor specializing in the study of diseased cells) analyzes the sample of diseased tissue from the biopsy, analyzing the cell structure and looking for patterns to determine the type of cells present in the tumor. This information is critical for doctors when crafting a specialized treatment plan.

Immunohistochemistry tests may also be used in conjunction with other tests to diagnose the specific mesothelioma cell type. Sometimes called IHC, this process uses antibodies to identify diseased tissue. Common immunohistochemical markers include cytokeratins, Calretinin, WT1 (the Wilms Tumor suppressor gene protein), and podoplanin (also called D2-40), an anti-podoplanin antibody.

Benign Mesothelioma

In rare cases, mesothelial tumors can be benign.  These masses tend to spread slower than malignant mesothelioma tumors. Due to its rarity, doctors and researchers still do not fully understand benign mesothelioma. However, if you are diagnosed with benign mesothelioma, you should still seek treatment to have the tumor(s) removed.