What Is Epithelioid Mesothelioma?
Epithelioid (or epithelial) mesothelioma is one of the three cell types of the rare cancer malignant mesothelioma. The other two mesothelioma cell types are sarcomatoid and biphasic.
Healthy epithelial cells typically develop from a type of tissue that forms as wounds heal, called a granuloma. When these cells are exposed to asbestos fibers, however, they can mutate and form mesothelioma tumors.
Malignant epithelioid mesothelioma cancer generally responds well to treatment. Patients with this cell type tend to live longer than patients with biphasic or sarcomatoid mesothelioma, provided that doctors can diagnose their cancer before it spreads.
Epithelial Cell Characteristics
- Adhere together in clumps
- Square, cubed, or flat shaped cells
- Clearly-visible nucleus
- Move slowly
Epithelioid Mesothelioma Symptoms
| Symptoms of Epithelioid Pleural Mesothelioma | Symptoms of Epithelioid Peritoneal Mesothelioma |
|---|---|
| Chest pain | Abdominal pain |
| Fatigue | Night sweats |
| Shortness of breath | Unexplainable weight loss |
| Fluid buildup in the chest (pleural effusions) | Fluid buildup in the abdomen (ascites) |
Epithelioid mesothelioma is usually accompanied by mild and vague symptoms at first. Many times, the cancer is commonly mistaken for other health problems with similar symptoms, such as pneumonia or asthma.
“In many cases, a persistent cough is the first symptom that prompts a visit with a physician.”
– Moffitt Cancer Center
Mesothelioma symptoms become more obvious and severe as the cancer spreads. The earlier a patient is diagnosed with mesothelioma, the better chances to treat the disease.
Epithelial Mesothelioma Diagnosis
Doctors follow a multi-step process to diagnose epithelioid mesothelioma after a patient reports symptoms.
1. Physical Examination
Doctors will first perform a physical examination to help determine the cause of the symptoms.
If the patient has a history of asbestos exposure, or if the doctor suspects mesothelioma for any other reason, they will look for specific signs of this cancer. One common indicator of mesothelioma is fluid buildup in the lung lining (pleural effusions).
2. Imaging Tests
If physical examination suggests signs of disease, doctors will use imaging tests to look for tumors, scar tissue, or other telltale signs of mesothelioma. Imaging tests may include X-rays, magnetic resonance imaging (MRI) scans, or computed tomography scans (CT scans).
One of the most critical benefits of imaging tests is that they can provide information on whether there are tumors present as well as the potential location of the mesothelioma.
3. Biopsy
Imaging tests can not conclusively diagnose mesothelioma, so if radiologists or doctors see visible cancer signs, they will request a biopsy.
The only way to confirm a mesothelioma diagnosis is through a biopsy, in which a piece of a tumor is removed or fluid is collected. The pathologist takes a fluid or tissue sample of the affected area and examines it under a microscope to see if mesothelial cells are present.
Once a diagnosis is made, the doctor can determine if the cancer cells belong to an epithelioid cell subtype.
Diagnosing Epithelioid Mesothelioma Using Biomarkers
Specialists will also look for biomarkers, which help them to distinguish mesothelioma cells from cells of other, similar illnesses and avoid misdiagnosis. This technique is called immunohistochemistry staining.
According to the American Society of Clinical Oncology (ASCO), the diagnostic process for epithelioid mesothelioma should include immunohistochemistry staining. This allows doctors to look for certain proteins (such as calretinin) and other signs of mesothelioma cancer.
Epithelioid Mesothelioma Prognosis
Patients with epithelial mesothelioma typically have a life expectancy of 1-2 years following their diagnosis.
Epithelioid mesothelioma generally has a better prognosis (expected outcome of a disease) than the other two cell subtypes — largely because epithelial cells spread fairly slowly. The table below details epithelioid patient survival compared to the other mesothelioma cell types.
| Mesothelioma Cell Type | Median Survival |
|---|---|
| Epithelioid | 18 months |
| Sarcomatoid | 10 months |
| Biphasic | 7 months |
In addition to cell type, other factors — including a patient’s age, cancer stage, and mesothelioma type — also affect a prognosis. Mesothelioma specialists take these factors into account when telling a patient their prognosis and prescribing available treatments.
Epithelioid Mesothelioma Treatment
Like all forms of this cancer, epithelial mesothelioma is usually treated using a combination of surgery, chemotherapy, and radiation (multimodal treatment). Epithelial cells are more responsive to these mesothelioma treatments than the other cell types.
Surgery
Removing tumors through surgery is the most effective way to treat epithelioid mesothelioma because it slows the spread of cancerous epithelial cells.
Patients with the epithelioid cell type are more likely to qualify for mesothelioma surgery when compared to patients with sarcomatoid cells or biphasic tumors.
The most common surgeries for patients with epithelioid pleural mesothelioma are extrapleural pneumonectomy (EPP) and pleurectomy with decortication (P/D). Patients with epithelioid peritoneal mesothelioma may qualify for cytoreductive surgery with HIPEC.
Chemotherapy
Chemotherapy for epithelioid mesothelioma is administered intravenously to stop cancer cells from spreading. Patients will typically need multiple rounds of chemotherapy.
Common chemotherapy drugs for mesothelioma include pemetrexed, cisplatin, carboplatin, and gemcitabine.
Radiation
Mesothelioma radiation therapy is administered by a machine that delivers high-energy wavelengths to the tumor site, which causes the epithelioid mesothelioma cells to die and the tumors to shrink.
Radiation may be used to supplement a surgery or as a main course of treatment if surgery is not an option.
Improving Prognosis With Treatment
Research has shown that multimodal treatment can improve the long-term survival rates of epithelioid mesothelioma patients.
According to a 2017 study, patients with epithelioid malignant pleural mesothelioma who received a combination of EPP surgery, chemotherapy, and radiation had a median survival time of about 23 months.
Patients with epithelioid mesothelioma may also access promising new treatment options through clinical trials, which test emerging treatments to hopefully improve survival rates and find a cure.
Rare Types of Epithelial Mesothelioma Cells
There are several subtypes of epithelioid mesothelioma, some of which are extremely rare and, in some cases, benign (non-cancerous).
These subtypes grow at different speeds and respond uniquely to treatments. For these reasons, identifying a patient’s epithelioid mesothelioma subtype allows oncologists to provide them with a more accurate prognosis.
Adenoid Cystic Mesothelioma
Cystic cells are rare and not fully understood. They are often benign and don’t usually spread to distant sites.
Adenomatoid Mesothelioma
Adenomatoid, also known as glandular epithelioid subtype, is very rare and generally originates within a patient’s genital glands. It accounts for roughly 6% of epithelioid mesothelioma cases in the pleura.
Deciduoid Mesothelioma
Deciduoid cells are characterized by their distinct borders and large oval shapes. This type of mesothelioma is associated with a very poor prognosis.
Papillary Mesothelioma
This subtype is much more common in women than men and is slow to progress. It is also rarely linked to asbestos exposure, unlike almost all other types of mesothelioma.
Small-Cell Mesothelioma
This extremely rare subtype is often mistaken for other small-cell cancers.
Hope for Victims of Epithelioid Mesothelioma
Epithelial mesothelioma patients may find hope in knowing that this cell type typically responds well to treatments. That said, if you have been recently diagnosed with epithelioid mesothelioma, you may still have questions or concerns.
You may be wondering how to provide for your family while you seek medical treatment — but, thankfully, there are support options available.
Learn how we can help you navigate life after an epithelioid mesothelioma cancer diagnosis. Download our free mesothelioma guide today.
Common Questions About Epithelioid Mesothelioma
What is the life expectancy for epithelial mesothelioma?
Epithelioid mesothelioma life expectancy is dependent on patients’ treatment plans. Generally, patients can expect a better survival rate if they undergo multimodality therapy, which consists of surgery, chemotherapy, radiation, and/or other treatments.
According to data from the Society of Thoracic Surgeons, patients who receive multimodality treatment live up to 2 years on average. Patients who undergo chemotherapy alone or no treatment at all have a life expectancy of approximately 15 months and 10 months respectively.
What is the difference between epithelioid mesothelioma and adenocarcinoma?
Adenomatoid mesothelioma, a subtype of epithelial mesothelioma, is sometimes mistaken for adenocarcinoma due to how the cells look under a microscope (histology).
Both mesothelioma and adenocarcinoma may develop on or around the lungs. That said, adenocarcinoma in the lungs is considered a type of lung cancer, while pleural epithelioid mesothelioma is not. It affects the lining of the lungs.
Pathologists can examine a patient’s cancer cells to determine whether they have epithelioid mesothelioma or adenocarcinoma. Receiving an accurate diagnosis is important in determining a patient’s life expectancy and treatment plan.
Where can I get treatment for epithelioid mesothelioma?
Not all hospitals have the equipment and staff to properly treat mesothelioma. For this reason, patients are encouraged to go to a specialized mesothelioma cancer treatment center to undergo surgery, chemotherapy/radiation, or other emerging therapies like immunotherapy.
Reach out to our team for help finding a mesothelioma treatment center near you.
