Medically Reviewed by: Erin Scheidemann, PhD | September 26th, 2025
Epithelioid mesothelioma is a subtype of mesothelioma, an aggressive cancer caused by exposure to asbestos. Cancerous epithelioid cells are found in an average of 60% of mesothelioma patients. In comparison to other mesothelioma subtypes, epithelioid mesothelioma cells often clump together and spread more slowly. Determining the subtype of mesothelioma helps doctors determine an accurate prognosis and an ideal treatment plan. Read more or download our guide to stay informed.
Epithelioid mesothelioma is a subtype of mesothelioma, an aggressive cancer caused by exposure to asbestos. Cancerous epithelioid cells are found in an average of 60% of mesothelioma patients. In comparison to other mesothelioma subtypes, epithelioid mesothelioma cells often clump together and spread more slowly. Determining the subtype of mesothelioma helps doctors determine an accurate prognosis and an ideal treatment plan. Read more or download our guide to stay informed.
Epithelial mesothelioma is a rare cancer that occurs when malignant epithelial cells spread along the lining of the lungs, abdomen, heart, or testes. The original site of the mesothelioma tumor develops a gene mutation from asbestos exposure. This mutation can occur in either epithelioid cells, sarcomatoid cells, or a combination of both.
The epithelial cell type comprises between 50% and 70% of mesothelioma cases. A small fraction (about 15%) of mesothelioma patients can have both epithelial and sarcomatoid cells, known as biphasic mesothelioma. Cancerous epithelial cells commonly develop in the lining of the bronchi, or the large tubes that connect to your windpipe and direct the air you breathe. Epithelioid cells clump easily, creating tumors, though they spread slowly.
Researchers have found that mesothelioma cell types have prognostic and predictive implications. Doctors use the mesothelioma cell type as a significant prognostic factor. Optimistically, the epithelioid cell type is associated with longer life expectancies among mesothelioma patients due to its nature to spread slowly. When treated with the top treatment options, patients living with epithelial mesothelioma can live an average of nearly two years longer than they would without treatment.
Epithelial cell mesothelioma symptoms are the same as those of any cell type. Thus, a person living with sarcomatoid cell mesothelioma may experience the same symptoms as someone with epithelial cell mesothelioma. The signs and symptoms of epithelial cell mesothelioma include:
You may find yourself undergoing several diagnostic procedures to confirm the presence of epithelioid mesothelioma cells. Most patients undergo imaging scans first to spot tumors, followed by a tissue biopsy that may find epithelial cells. Additional lab tests can be done to detect other characteristics of the cell type.
A pathologist can distinguish between epithelial and other types of mesothelioma cells by using specialized cancer-detecting antibodies. The antibodies find and bind to certain proteins on the surface of malignant epithelial cells. The pathologist can detect epithelial cells by testing a sample of the affected tissue.
Malignant epithelial cells can appear square, long, or flat. Doctors sometimes find difficulty distinguishing epithelial mesothelioma from a more common condition called adenocarcinoma (a cancer that occurs in glandular cells that line the organs). However, modern diagnostic techniques often require testing a tissue sample to confirm mesothelioma.
Due to the rarity of the disease, most doctors have never diagnosed mesothelioma. Certain multidisciplinary mesothelioma doctors, including surgeons, radiologists, or oncologists, specialize in diagnosing and treating the disease. They have experience and can identify rare characteristics of mesothelioma, including cell subtypes.
We can classify epithelioid mesothelioma even further by distinguishing the cell subtype. Epithelioid cells vary in characteristics, distribution, and progression. To identify the best treatment option for each unique mesothelioma diagnosis, a pathologist determines the subtype of epithelioid mesothelioma from a variety of options.
Treatment for epithelial mesothelioma varies based on where the cells originate and how far they spread. Epithelioid mesothelioma cells typically originate in the lining of organs. Mesothelioma patients experience better survival rates when physically able to undergo multiple treatments, including radiation and surgery. Tumors containing epithelioid cells spread and are typically easier to access and treat.
Epithelial mesothelioma treatment options often include a combination of immunotherapy, chemotherapy, and surgery (if possible). When mesothelioma patients are physically able to undergo surgery, they may receive chemotherapy or radiation to suppress any remaining cells following the procedure. Modern treatments can be accessed at some of the top mesothelioma medical centers around the United States.
One study of patients with epithelial mesothelioma found the median survival without treatment was just over 10 months. Meanwhile, patients who underwent chemotherapy alone survived a little over 15 months. Patients who underwent surgery and received chemotherapy and/or radiation survived over 21 months.
Treatment for this rare disease requires the expertise of a team of mesothelioma specialists. Mesothelioma specialists have experience with the diagnostic and treatment process, and each serves a specific need of the patient. A mesothelioma care team may include medical, radiation, and surgical oncologists, pathologists, nurses, pulmonologists, and many more.
If you or a loved one has been diagnosed with epithelioid mesothelioma, know that you are not alone. In addition to advanced treatment options, families affected by asbestos-related diseases may be entitled to financial compensation. Legal claims, settlements, and trust funds can help cover medical expenses, lost income, and future care needs. While no amount of money can undo the harm caused by asbestos exposure, compensation can ease the financial burden and bring a measure of justice. Our dedicated patient advocates are here to help you understand your treatment options and connect you with experienced mesothelioma lawyers who can guide you through the claims process. Reach out today to learn more about how we can support you and your family.
Rachel Ernst is a content writer at Mesothelioma Hub. She graduated with a Bachelor of Arts degree from the University of Illinois at Chicago, where she majored in communication and minored in sociology. She hopes to create public awareness about cancer through her writing. In her free time, Rachel likes to be outdoors, watch movies, and spend time with her animals.
Erin earned a Bachelor of Science in Biology from The College of New Jersey in 2020 and a
Doctor of Philosophy in Tumor Biology from Georgetown University in 2024. Erin is passionate about making health information accessible and informing people about the latest research that can impact their lives.
Brcic, L. & Izidor, K. (2020). Clinical significance of histologic subtyping of malignant pleural mesothelioma. Retrieved on September 16, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7354152/
Gill, R., et al. (2012). Epithelial Malignant Pleural Mesothelioma After Extrapleural Pneumonectomy: Stratification of Survival With CT-Derived Tumor Volume. Retrieved on September 16, 2022, from https://www.ajronline.org/doi/pdfplus/10.2214/AJR.11.7015?src=recsys
Malpica, A., et al. (2012). Well-differentiated papillary mesothelioma of the female peritoneum: a clinicopathologic study of 26 cases. Retrieved on September 16, 2022, from https://pubmed.ncbi.nlm.nih.gov/22024662/#:~:text=Well%2Ddifferentiated%20papillary%20mesothelioma%20(WDPM,biological%20behavior%20is%20still%20limited.
Martini, N., et al. (1987). Plural Mesothelioma. Retrieved on September 16, 2022, from https://www.annalsthoracicsurgery.org/article/S0003-4975(10)60182-8/pdf
Ohara, Y., et al. (2020). Connective tissue growth factor produced by cancer-associated fibroblasts correlates with poor prognosis in epithelioid malignant pleural mesothelioma. Retrieved on September 16, 2022, from https://pubmed.ncbi.nlm.nih.gov/32705221/