Epithelioid Cell Type

Quick Summary

Healthy epithelial cells are found in abundance throughout the body, and when exposed to asbestos, a cancer-causing carcinogen, they can mutate into cancerous epithelioid cells, the most common cell type of mesothelioma. Patients diagnosed with epithelioid cell type generally have the best prognosis, as epithelioid cells spread slowly throughout the body and therefore respond best to a wide range of aggressive treatment plans.

Epithelioid Cell Type Overview

If you’ve been diagnosed with mesothelioma, it’s important to have a good understanding of how the disease matastasizes (spreads) throughout the body. Cell type determines this rate of metastasis.

Here’s what to know if you have epithelioid cell type:

  • Epithelioid is the most common cell type of mesothelioma
  • Epithelioid cells are elongated, with visible DNA and pink cellular material
  • Their shape causes them to lump together, slowing their spread through the body
  • Epithelioid cell type responds best to treatment and has the most favourable prognosis
  • Possible treatment plans for epithelioid cell type include surgery, chemotherapy and radiation therapy

What is the Epithelioid Cell Type?

The cell types present within a malignant (cancerous) mesothelioma tumor differ in physical characteristics and growth behavior. These differences can have a large impact on patients who are diagnosed with mesothelioma, especially when discussing therapy options with their doctors. Cell types also play a crucial role in patients’ quality of life, length of life and overall prognosis.

Healthy epithelial cells are found all over the body in the lining of organs in the chest and abdomen. When exposed to asbestos, epithelial cells can genetically mutate and present as epithelioid mesothelioma cell type. Epithelioid mesothelioma is characterized by elongated cells that replicate on top of each other forming lumps. Epithelioid is the most likely mesothelioma cell type to form in the organs tissue linings‚making up around 50 to 70% of diagnosed cases. Patients diagnosed with epithelioid cell type generally have a better prognosis and more treatment options compared to sarcomatoid or biphasic cell types.

Along with tumor location and cancer stage, a patient’s particular mesothelioma cell type plays an important role in their overall diagnosis. When doctors test mesothelioma tumor samples they observe varying characteristics and behaviors to determine which cell type is present to ensure optimal treatment plans are developed. Determining the type of mesothelioma cell type is especially important to understanding which level of aggression needs to be integrated into a patient’s treatment plan.

Epithelioid Cell Type Characteristics

When disease symptoms appear and a cellular mass (tumor) is found, medical professionals collect tumor samples and view them under a microscope—a procedure called a biopsy. Observations help doctors differentiate the sample from many different diseases. Understanding the characteristics of a cell is very important in ensuring a proper diagnosis is made.

Did You Know? Epithelioid cells display similar characteristics as lung cancer when mesothelioma is found in the chest (pleural), and ovarian cancer when mesothelioma is found in the abdomen (peritoneal). For this reason, multiple tests are performed on mesothelioma samples to determine an accurate diagnosis.

When a mesothelioma tumor sample containing epithelioid cells is viewed under a microscope, the cells are typically cube-like and elongated in shape. Epithelioid cells usually contain a very visible nuclei (the cell’s DNA center) and pink cytoplasm (the material that the cell is composed of). Epithelioid cells can be further classified into subtypes (see below) which have varying characteristics.

Epithelioid Cell Type Behavior

Each mesothelioma cell type displays different behaviors, which determines the rate at which they replication and spread. These cellular behaviors have been found to play a large role in patient life expectancy and survival rate.

The square cell shape of epithelioid mesothelioma allows them to divide and replicate faster than sarcomatoid or biphasic cell types. But, their square shape causes epithelioid cells to stick together, because they build upon themselves as they replicate. This lumping behaviour means the cells are slow to spread to other parts of the body and results in a better prognosis in comparison to other cell types. Lumped cell growth also makes epithelioid tumors easier to resect (remove) surgically.

Epithelioid Subtypes

There is a wide range of epithelioid cell subtypes, which display further unique characteristics and behaviors. When observing an epithelioid mesothelioma tumor sample under a microscope, it is possible to identify more than one epithelioid subtype.

Mesothelioma Cell Type Update

Just recently, scientists have found that cellular differences in epithelioid subtypes—growth behaviors, in particular—have a large impact on patient prognosis.

Epithelioid subtypes also provide doctors with more clues to correctly diagnose epithelioid mesothelioma, as many of these subtypes originate in specific parts of the body, are extremely rare or sometimes benign (non-cancerous).

  • Tubulopapillary: Tubulopapillary cells have many different patterns showing tubules and extensions that coexist in the same area. Tubulopapillary cells are the most common subtype of epithelioid mesothelioma.
  • Acinar: Acinar cells have are a well-defined, elongated shape that is lined with cube-like cells.
  • Solid: Solid cells present in either clearly separated or poorly separated sheets and patterns and are a common subtype of epithelioid mesothelioma.
  • Deciduoid: Deciduoid cells are oval in shape with very distinct borders. They are very uncommon and were originally found in patients with no exposure to asbestos before recent studies found mutated cells derived from a history of exposure to asbestos
  • Micropapillary: Micropapillary cells have patterns of papillary structures without fibrovascular (fibers and conducting cells) cores. This epithelioid subtype has a higher chance of entering the lymphatic part of the circulatory system.
  • Trabecular: Trabecular cells following patterns of small uniform cells that are arranged in thin cords.
  • Cystic: The understanding of cystic cells is limited due to their rare occurrence. Most cases are found to be benign with a very low possibility of the subtype spreading to other parts of the body.
  • Adenomatoid: Adenoid or Microglandular cells are very rare and normally originate in a patient’s genital glands. This particular subtype is diagnosed as benign more commonly in men than women.
  • Glandular: Glandular epithelioid cells are usually found in cases of pleural mesothelioma.
  • Clear: Clear epithelioid cells usually contain clear cytoplasm.
  • Small: Small epithelioid cells are very rare and are characterised by uniform small, round cells that are also found in other types of cancer.

Epithelioid Cell Type Prognosis

Prognosis is used in the medical field to describe the possibility of recovery based on the usual progression of disease. There are many different factors that are taken into consideration when predicting a patients life expectancy after diagnosis—from age, gender, disease location, cancer stage to the patient’s overall health. Among these factors, the prognosis of patients who are diagnosed with mesothelioma is also dependent on cell type.

Epithelioid mesothelioma has the most favourable prognosis in comparison to sarcomatoid and biphasic cell types, with an average survival time of 1-2 years following diagnosis.

 In a study conductlooked at eighty-four cases of epithelioid mesothelioma found in the abdomen with tubulopapillary, micropapillary and solid cell subtypes that were treated with chemotherapy. Results showed ed in 2016, scientists that the average survival rate among all subtypes was 36 months. Patients with solid epithelioid mesothelioma had shorter overall survival (average, 29 months) than patients with tubulopapillary and micropapillary growth patterns (average, 51 and 53 months).

Prognosis varies heavily on location, with the longest survival rates found in patients with peritoneal (abdomen) mesothelioma, followed by plural (chest) mesothelioma, and lastly pericardial (heart) mesothelioma. Life expectancy and survival of mesothelioma is greatest in epithelioid cell type across all locations, especially in cases that are detected at an early stage. In general, epithelioid mesothelioma responds well to treatment, which presents patients with numerous treatment options to achieve the best possible prognosis for their location, stage and cell type.

Treatments for Epithelioid Mesothelioma

When developing treatment plans, doctors take a patient’s age, overall health, previous response to treatments, disease location and stage into account. In cancer care, doctors often consult with other medical professionals to create a multidimensional treatment plan for patients to ensure the best prognosis.

Treatments for mesothelioma are dependent on location and stage, and is generally consistent across all cell types. However, doctors may recommend a more aggressive treatment plan for patients diagnosed with epithelioid mesothelioma as this cell type responds best to treatment. Treatment plans for epithelioid mesothelioma can include a mixture of surgery, chemotherapy, and radiation therapy to remove or shrink tumors.

For more information on treatment for an epithelioid mesothelioma diagnosis, contact out Patient Advocates today.

View Author and Sources

  1. Journal of Clinical Pathology, “My approach to the diagnosis of mesothelial lesions”
    Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1860395/. Accessed on February 19, 2018.
  2. American Society of Clinical Oncology, “Mesothelioma: Introduction”
    Retrieved from: https://www.cancer.net/cancer-types/mesothelioma/introduction. Accessed on February 19, 2018.
  3. Environmental Health and Preventive Medicine, “Pathology of mesothelioma”
    Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2698271/. Accessed on February 19, 2018.
  4. PathologyOutlines.com, “Pleura Mesothelial tumors. Mesothelioma - Epithelioid” Retrieved from: http://www.pathologyoutlines.com/topic/pleuramesotheliomaepithelioid.html. Accessed on February 19, 2018.
  5. Alyssa M Krasinskas, Histopathology, “Prognostic significance of morphological growth patterns and mitotic index of epithelioid malignant peritoneal mesothelioma” Accessed on February 19, 2018.
  6. Hartman DJ, Histopathology, “Reproducibility for histologic parameters in peritoneal mesothelioma” Accessed on February 19, 2018.

Last modified: February 23, 2018