Histopathology is used to diagnose mesothelioma. It is also the study of how the disease itself develops. This practice is essential to determining a patient’s prognosis.

Detecting Mesothelioma

After a doctor takes a biopsy, a histology report is needed to declare a definitive mesothelioma diagnosis. Histology reports are lab tests used to detect mesothelioma in tissue samples under a microscope. These tests are the most important factor in determining a patient’s prognosis.

Importance of Histology

  • Better Diagnosis

    Histology reports of a biopsy are the only way to definitively determine if a patient has mesothelioma. Histology reports are essential to determining the mesothelioma cell type (epithelioid, sarcomatoid or biphasic).

  • Getting Treatment

    A histology report is the biography of the patient’s disease. By knowing all the details of the disease, doctors are able to make the most informed decisions on treatment, ensuring the most effective options possible. Learn more about your treatment options in our free Mesothelioma Guide.

  • Accurate Prognosis

    Histology is also essential to giving a patient an accurate prognosis. It is through the histology report that doctors learn things like the patient’s cell type and sometimes even the extent of metastasis.

What is Histology?

Histology is the study of animal tissue at the microscopic level. Therefore, mesothelioma histology is the microscopic study of tissue sample affected by mesothelioma. Without histology, doctors would not be able to learn more about the underlying functions of the disease. It would also be far harder to diagnose.

What’s Pathology Got to Do With It?

Mesothelioma histology also comprises the field of pathology, which is the study of the causes and effects of diseases. The terms histology and pathology are often used interchangeably in this case because pathologists naturally rely on the examination of diseased tissue, which is sometimes referred to as “histopathology.”

Diagnosis Through Histology

The latency period and symptoms associated with mesothelioma are two factors that account for the difficulty in diagnosing the disease. However, pathologists, who make the final judgment call on diagnosis, run into a different set of issues. Mesothelioma is hard to diagnose for several reasons:

  • 1
    Mesothelioma mimics other diseases.
  • 2
    There are various cell types of mesothelioma.
  • 3
    Doctors must differentiate between benign and malignant cells.

Mesothelioma can be hard for doctors to distinguish from other types of cancers because it is so rare and looks like other cancers. Epithelioid mesothelioma is sometimes misdiagnosed as more common carcinomas, and peritoneal mesothelioma has even been misdiagnosed as ovarian cancer.

What Happens to Mesothelioma Biopsies?

A histology report cannot be completed without a biopsy, or a sample of the diseased tissue. After a biopsy is taken, it is preserved in formaldehyde and sent to the pathology lab. The pathologist gives the tissue a visual assessment before placing it under a microscope. They take into account things like the size, color and consistency of the sample.

After the pathologist visually evaluates the sample and takes note of the tissue, the sample is dipped into hot paraffin wax. Once the wax cools, the sample is cut into thin slices. Each slice is placed on a glass slide and dipped into various chemical dyes “stain” the sample and makes certain cells visible under the microscope.

After the stains are added, these specimens are carefully examined and compared to many other diseases. Different stains and comparisons are necessary because there are other diseases that react similarly to mesothelioma when introduced to certain stains. The whole process is typically conducted overnight.

Identifying Mesothelioma

The actual diagnosis of mesothelioma depends on the examination of the tissue taken from the tumor origin and examined under a microscope. Imaging scans and early diagnostic methods are only useful in determining that something is wrong and where.

Under the microscope, pathologists can examine the attributes of the sample and determine if it is mesothelioma. The pathologist has to rely on many different chemical stains to assess whether or not the patient in fact has mesothelioma.

Other things pathologists look for are:

  • Cellular behavior
  • Cell size and shape
  • Cell nuclei
  • Cell pattern of the sample

Finding certain cells where they don’t belong can be a clue to the presence of mesothelioma. Healthy cells typically remain in the area where they grow (skin cells stay with other skin cells for example), whereas mesothelioma cells spread and invade other parts of the body without discretion.

Pathologists face certain difficulties when studying mesothelioma samples. For example, inflammation and healing in the lining of the chest or abdomen can create histological changes in the tissue sample. This causes cells to move around and look slightly different than, say, another sample that is also mesothelioma.

An example of this can be elucidated by chest infections. The infection must be fought off by the body and there is a flux in white blood cells, which would make the histology look different due to the presence of more cells.


A word commonly seen in the fields of histology and pathology is “immunohistochemistry.” This is another method of examining mesothelioma tissue samples by introducing a foreign substance to the sample and then examining the results. In this case, antibodies are introduced that react with mesothelioma cells.

Antibodies in Immunohistochemistry

Antibodies are the part of the immune system (hence the “immuno” in “immunohistochemistry”) that identify foreign invaders like bacteria and viruses. These antibodies are also attracted to proteins found on the surface of mesothelioma cells.

By examining the reaction of these proteins to certain antibodies, doctors are able to recognize certain diseases, like mesothelioma. There isn’t any one antibody that presents a positive stain of mesothelioma so pathologists have to conduct multiple tests.

Misdiagnosis and Second Opinions

All the difficulties associated with the histological diagnosis of mesothelioma contribute to a possible misdiagnosis. Doctors are still humans subject to error and they may miss certain attributes under the microscope that another doctor catches.

This makes second opinions essential for all patients diagnosed with mesothelioma before they receive any treatment. The best way to ensure an accurate diagnosis is to see an experienced mesothelioma specialist. Get connected with top specialists across the country to get your second opinion.