Mesothelioma Diagnosis

Quick Summary

Doctors use a variety of tools to make a mesothelioma diagnosis. They will examine your symptoms, then perform imaging tests (X-rays, MRIs, or CT scans), and confirm the diagnosis with a biopsy. An accurate mesothelioma diagnosis is critical to receive the best treatment.

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Steps to Diagnose Mesothelioma

A mesothelioma cancer diagnosis usually starts with your symptoms, according to the American Cancer Society (ACS). Most patients see their doctors to get a physical exam a few months after the first symptoms of mesothelioma set in.

View Summary: Registered Nurse Amy Fair discusses the team of doctors that are involved when getting a mesothelioma diagnosis. View Transcript.

Who should be on my medical team for treatment?

The health care professionals that are involved in the diagnosis of mesothelioma many times start with your primary doctor because of the symptoms of a cough or shortness of breath.

Many times they are referred then on to a pulmonologist if the symptoms don’t resolve. After the pulmonologist does a CT scan or a chest X-ray and notes a mass in the pleura or the abdomen, they will refer them on to a thoracic surgeon to have that biopsy to confirm the disease.

The surgeon, after getting the diagnosis, will then refer them on to either a radiation oncologist or oncologist for treatment.

At first, your doctor may suspect a common condition like pneumonia or irritable bowel syndrome is causing your symptoms. You may then need to get imaging scans from a pulmonologist (respiratory system doctor) or oncologist (cancer doctor).

Pulmonary specialists and oncologists have more experience examining symptoms and performing tests than general doctors, especially when cancer is suspected.

Pleural Mesothelioma SymptomsPeritoneal Mesothelioma Symptoms
Chest painAbdominal pain
CoughNausea and vomiting
Shortness of breathWeight loss

When you get an appointment with a mesothelioma specialist, prepare to spend up to an hour at the first consultation. Expect several follow-up visits and multiple tests in order to make the diagnosis. It is very rare to be diagnosed with mesothelioma in a single visit.

Mesothelioma Diagnosis & Asbestos Exposure

Your history of asbestos exposure can be crucial in helping doctors make a diagnosis of mesothelioma. Asbestos is the biggest risk factor and only known cause of this deadly cancer.

“A suspicion of mesothelioma should always arise when a patient with a case history of reasonable asbestos exposure is examined for pleural effusion or pleural masses of unknown [origin].”

– European Respiratory Journal

Your doctor will help determine if you were exposed to asbestos by asking about your work and military service history.

Veterans have an increased risk of getting mesothelioma due to asbestos exposure in the military. Veterans who worked in shipbuilding, naval shipyards, or construction have the highest rates of asbestos exposure. Non-veterans can also be exposed through blue-collar work.

With a detailed exposure history, doctors are more likely to go straight to specific tests for mesothelioma.

Imaging Tests for Mesothelioma

Imaging scans are the first type of test mesothelioma doctors will use if cancer is suspected. These tests cannot confirm a mesothelioma diagnosis but they can help doctors see if cancerous tumors may be present.

One or more of the following imaging tests may be used.


An X-ray is often the first scan doctors perform when making a mesothelioma diagnosis.

  • How Doctors Use X-Rays

    X-rays can show a fluid buildup in the lungs or abdomen and thickening in the lining of the lungs.

Chest X-rays are most helpful when doctors need to make a malignant pleural mesothelioma diagnosis.

Computed Tomography (CT) Scans

CT scans may be ordered of the chest, abdomen, or both. CT scans take longer than X-rays, but they produce more detailed images.

CT scans use X-ray energy and a computer to create cross-sectional pictures of the organs inside the body. Doctors can see the size and location of tumors more easily with these scans. This test is helpful for locating peritoneal tumors.

Magnetic Resonance Imaging (MRI)

An MRI is useful when determining how far mesothelioma has spread, including to nearby lymph nodes and organs.

A doctor may take MRI scans of the chest and/or abdomen. Like a CT scan, it creates cross-sectional pictures of the organs inside the body. MRI scans use strong magnets and radio waves to see bones, soft tissue, and organs in the chest and abdomen.

Positron Emission Tomography (PET) Scans

PET scans use radioactive proteins to identify potentially cancerous cells within the body.

  • How PET Scans Work

    Before a PET scan, patients are injected with radio-labeled sugar that is absorbed by cancer cells more than other cell types. The PET scan then finds the cells that absorbed the sugar.

While a combination of CT and PET scans are usually better when making a mesothelioma diagnosis, your doctor can use any of these tests to see if possibly cancerous tumors are present.

Mesothelioma Biopsies

A biopsy is the only way to confirm if you have mesothelioma. Through a biopsy, a tissue or fluid sample is taken from a potentially cancerous area found on an imaging test.

Types of biopsies include:

  • Needle biopsy: A thin, hollow needle is inserted through your skin, guided by imaging techniques. Fluid and/or tissue can be drawn up through a syringe.
  • Thoracoscopy: A camera is attached to the end of a tube and is inserted into the lung cavity by way of a thoracotomy (chest incision). The cancerous areas can be seen with the camera and the biopsy is taken using small tools attached to the thoracoscope.
  • Mediastinoscopy: This test is similar to a thoracoscopy. The tube is inserted near the neck. There is a camera that can show areas that look cancerous and take a sample from them.
  • Laparoscopy: This is a test to look for peritoneal mesothelioma. A camera attached to the end of a tube is inserted into the suspected part of the abdomen after a laparotomy (abdominal incision) is performed.
  • Incisional biopsy: This is also called a core biopsy. Doctors take a larger sample of the possibly cancerous mass but do not remove it entirely
  • Excisional biopsy: In this type of biopsy, an attempt is made to remove all visible signs of cancer.

It may take up to two weeks to get scheduled for a biopsy. It can take up to two more weeks to get a mesothelioma diagnosis after a biopsy has been taken.

Mesothelioma Pathology Tests

After your doctor has performed a biopsy, the tissue sample needs to be reviewed under the microscope by an expert pathologist.

Pathologists will be able to determine if there are mutations among healthy cells, which is how cancer is found. Then the pathologist notes the characteristics of the cancerous cells.

  • Studying Mesothelioma Cells

    Mesothelioma cells have specific traits that can be revealed by immunohistochemistry, which selectively exposes special antibodies only found on these cells.

More biopsies or further testing may be necessary to make an official mesothelioma diagnosis, as mesothelioma can sometimes be mistaken for other types of cancer. Adenocarcinoma and mesothelioma have similar cellular structures.

Electron microscopy can help doctors distinguish mesothelioma cells from adenocarcinoma. This type of imaging uses an electron microscope to get a much higher magnification of a biopsy or fluid sample.

Blood Tests for Mesothelioma

Because of recent research, blood tests called biomarker tests have been found effective in some mesothelioma patients. Doctors are developing blood tests that may one day lead to earlier diagnoses.

Did you know

There is a Food and Drug Administration (FDA) approved test called MESOMARK, which tests for proteins found on mesothelioma cells called soluble mesothelin-related peptides (SMRPs). Mesothelioma patients often have high levels of SMRPs in their blood.

Another biomarker tests for a protein known as osteopontin. There are elevated levels of this protein in some mesothelioma patients, though the levels also rise with other conditions. Researchers are still testing how reliable osteopontin is to diagnose mesothelioma.

Blood tests can help confirm a mesothelioma diagnosis, but scans and biopsies still need to be done to determine if the cancer is present.

Difficulties With Making a Mesothelioma Diagnosis

Mesothelioma can be hard to diagnose. Most people don’t receive a final mesothelioma diagnosis until 2-3 months after the onset of their symptoms.

Several factors can affect a mesothelioma diagnosis, including:

  • Nonspecific symptoms: Mesothelioma symptoms are similar to those of many other diseases. Many conditions cause weight loss, coughing, fatigue, and chest pain. Mesothelioma is so rare that it is not the first thing doctors think of unless they know you have a history of asbestos exposure.
  • Imaging scan issues: Small areas of mesothelioma just look like thickening of the pleura (the lining of the lungs), and it might not be visible at all on an X-ray. Many patients need a CT or MRI scan of the chest to see the areas of cancer.
  • Difficulty getting an accurate biopsy: As previously mentioned, a pathologist might have trouble diagnosing mesothelioma because it can look like other kinds of cancer. More biopsies or further examination may be necessary to avoid a mesothelioma misdiagnosis.

Next Steps After a Mesothelioma Diagnosis

Eventually, your doctor will confirm your mesothelioma diagnosis. Your specialist may run other tests to get a more accurate picture of your diagnosis.

Further testing helps doctors create a tailored mesothelioma treatment plan based on your specific situation.

Did you know

Surgeries, chemotherapy, and radiation therapy all may be used to treat this cancer. Specialists may also be a part of clinical trials testing new ways of treating mesothelioma.

In some cases, you may want to request a second opinion to make sure your mesothelioma diagnosis is correct. A second opinion may even reveal new treatment options that prolong your survival time.

Get a Mesothelioma Diagnosis from Top Doctors

If you believe you may have symptoms of mesothelioma, don’t wait: connect with a mesothelioma doctor immediately. An early diagnosis can help improve your life expectancy and treatment options.

Things to remember about a mesothelioma diagnosis:

  • Biopsy samples are the only conclusive way to diagnose mesothelioma
  • Sometimes mesothelioma is confused with other types of cancer
  • If you haven’t yet, talk to your doctor about a second opinion

Our team can help you learn more about getting a diagnosis and exploring your next steps. Contact us today.

Veterans Support Team
Todd Gersten, MD PhotoReviewed by:Todd Gersten, MD

Double Board-Certified Oncologist and Hematologist

  • Fact-Checked
  • Editor

Todd Gersten, MD is a double board-certified medical oncologist and hematologist specializing in general adult oncology and hematologic disease. He is a physician partner with the Florida Cancer Specialists and practices in Wellington, Florida.

Dr. Todd Gersten is an independently paid medical reviewer.

Christopher Dryfoos PhotoWritten by:

Contributing Author

Christopher Dryfoos is a journalist and member of the American Medical Writers Association (AMWA). As the grandson of the U.S. Navy’s first forensic pathologist, he aims to help veterans with mesothelioma access needed care.

View 5 Sources
  1. American Cancer Society. (n.d.). How Is Malignant Mesothelioma Diagnosed? Retrieved September 24, 2020, from
  2. American Cancer Society. “Can Malignant Mesothelioma Be Found Early?” Retrieved from: Accessed on August 28th, 2017.
  3. American Society of Clinical Oncology. (Feb. 2019.) Mesothelioma: Diagnosis. Retrieved from
  4. G. Martensson. European Respiratory Journal. “Diagnosing malignant Pleural Mesothelioma.” 1990. Retrieved from: Accessed on August 28th, 2017.
  5. National Cancer Institute. (Mar. 2019.) Malignant Mesothelioma Symptoms, Tests, Prognosis, and Stages (PDQ®)–Patient Version. Retrieved from
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