Epithelioid Mesothelioma

Most mesothelioma patients have an epithelioid cell type, which occurs in 70 percent of all diagnoses. It is the most treatable type of mesothelioma.

What is Epithelioid Mesothelioma?

Epithelial cells, which are healthy and prevalent in the human body, can mutate into deadly epithelioid mesothelioma cells when exposed to asbestos. Patients with epithelioid mesothelioma often have a better prognosis and more treatment options than those with sarcomatoid or biphasic cell types. Learn more about improving your epithelioid prognosis in our free Mesothelioma Guide.

Characteristics of Epithelioid Mesothelioma

Cell Prevalence

Epithelioid mesothelioma is the most common diagnosis and has the best prognosis. It is most common in white men over the age of 45 with a pleural diagnosis.

Cell Description

Epithelioid cells have a clearly defined, elongated egg-shape. Their visible nuclei make it easier to distinguish this cell type.

Cell Behavior

Epithelioid cells divide faster than other mesothelioma cell types, contributing to faster tumor growth. However, the cells stick to each other, which slows down metastasis.


Epithelioid cell types make up 70 percent of pleural mesothelioma diagnoses, but they are also found in peritoneal diagnoses.

They also closely resemble cell types that make up adenocarcinoma, breast cancer, and other forms of carcinoma (cancer that affects the lining of internal organs).

The symptoms of epithelioid mesothelioma may include: shortness of breath, chest pain or pleural effusions (fluid buildup). In order to diagnose a patient, a physician uses radiology or pathology examinations to see if there is a presence of malignant mesothelioma cells. After determining the presence of these cells, the physician may ask about asbestos exposure and take a biopsy.

If cancerous cells are found in the biopsy, a physician may use a process called immunohistochemistry. This process detects proteins that are used as cancer markers in the cellular makeup of a sample that is taken. This process is also the only way to definitively diagnose mesothelioma.


Subtypes of epithelioid mesothelioma have different sizes, shapes and structures. They all contain epithelioid cells; however, these subtypes may react differently to certain treatment plans.

  • Adenoid – Adenoid epithelioid cells may be present in all of the types of mesothelioma. They may also mimic other types of tumors, which may make it difficult to diagnose a patient.
  • Small Cell – Small cell mesothelioma is distinct in the patterns of the shape of the cells. It is common in peritoneal mesothelioma patients and very difficult to treat.
  • Cystic – Cystic mesothelioma cells are very rare and are generally found in patients with peritoneal mesothelioma. It is more common in women than it is in men.
  • Papillary – Papillary mesothelioma is far less aggressive than other forms, but it is also rare. It is usually found in the peritoneum.
  • Deciduoid – Deciduoid mesothelioma is a rare cell type in pleural mesothelioma. However, it is very common in peritoneal, accounting for 50 percent of cases.


Treatment for epithelioid mesothelioma is often the same for the other types of mesothelioma. Fortunately, treatment for epithelioid type mesothelioma is more effective than other types of mesothelioma.

Some patients may be eligible for an extrapleural pneumonectomy (EPP), which can significantly increase life expectancy. If tumors haven’t spread from the pleura to the actual lung patients may take advantage of a lung-sparing pleurectomy with decortication (P/D).

Those with epithelioid peritoneal mesothelioma may take advantage of cytoreductive surgery. There is no excepted staging system for peritoneal mesothelioma so finding a specialist and getting a second opinion are more important than ever.

However, other standard forms of treatment are also used, such as chemotherapy and radiation. There have also been successes with alternative treatment options, such as gene therapy, photodynamic therapy, and intensity modulated radiation therapy. These types of treatment methods are currently being researched in hopes of developing a mesothelioma cure.


Cell type is one of the most important factors that affect a patient’s prognosis. The prognosis for patients with epithelioid mesothelioma is often better than biphasic or sarcomatoid cell types.

One study showed that 60 percent of patients who were treated for epithelioid mesothelioma survived at least a year after their initial treatment started. About 25 percent of those patients lived longer than five years.

There are many ways patients with epithelioid mesothelioma can improve their survival, such as seeing a specialist or opting for new treatments. Learn which methods mesothelioma survivors used to extend their life in our free Mesothelioma Survivors Guide.