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Mesothelioma Diagnosis

Doctors can use imaging tests, blood tests, and biopsies to diagnose mesothelioma. Because this cancer is so rare and aggressive, it’s important to get diagnosed as soon as possible. An early and accurate mesothelioma diagnosis is your key to starting potentially life-extending treatments. Learn more about getting a diagnosis and how Mesothelioma Hope can help.

Medically Reviewed and Fact-Checked by: Dr. Mark Levin

Updated by: Laura Wright on

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How Is Mesothelioma Diagnosed?

To make a mesothelioma diagnosis, doctors will often first monitor initial symptoms such as a dry cough, chest pain, shortness of breath, and weight loss. They’ll also want to know if you or a loved one was ever exposed to asbestos, which is the only known cause of mesothelioma.

Once the doctor rules out that more common conditions are not causing these symptoms, they will perform various tests for mesothelioma.

Mesothelioma can be diagnosed using:

  • Biopsies
  • Blood tests
  • Imaging tests

However, a biopsy is the only definitive way to confirm a mesothelioma diagnosis.

Quick Facts: Mesothelioma Diagnosis
  • Approximately 3,000 people are diagnosed with mesothelioma each year.
  • Mesothelioma is usually diagnosed 10-50 years after exposure to asbestos.
  • Most people diagnosed with mesothelioma are 65 years old or older.
  • Mesothelioma can be diagnosed in younger adults, teenagers, children, and even dogs.

Once a diagnosis of mesothelioma has been confirmed, your doctors can determine your prognosis and recommend treatments that can help you live as long as possible with this cancer.

A mesothelioma prognosis is the likely course that the disease will take, including your estimated life expectancy.

Talk with your doctor as soon as possible if you or a loved one is experiencing mesothelioma symptoms. Prompt detection and diagnosis of mesothelioma is essential to receiving life-extending treatment.

Get our Free Survivors Guide to read 7 empowering stories of mesothelioma patients who increased their life expectancy with prompt diagnosis and treatment.

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Diagnosing Different Types of Mesothelioma

Doctors use certain techniques and equipment to make a mesothelioma diagnosis depending on where in the body the potentially cancerous cells are located.

Here are the common tests used for each type of mesothelioma:

  • Pleural mesothelioma: CT scans, MRIs, and ultrasounds can be used to determine if cancer is present in the pleura (lung lining). PET scans may be used to see how far the cancer has spread. Pulmonary function tests can also determine if the lungs have been weakened by the cancer.
  • Peritoneal mesothelioma: Peritoneal mesothelioma forms in the abdominal lining, or pleura. If this cancer is suspected, doctors typically start with a CT scan of the abdomen. Blood samples may be taken to help rule out other conditions.
  • Pericardial mesothelioma: This type of mesothelioma forms in the lining of the heart. Chest X-rays, MRI scans, and echocardiograms may be used to see if cancer tumors have started to develop around the heart. Most cases are only diagnosed after the patient has died since this type of mesothelioma is extremely rare.
  • Testicular mesothelioma: Doctors may use X-rays, ultrasounds, and biomarkers (tests that look for substances like proteins that only cancer cells give off) to diagnose this type of cancer, which forms in the lining of the testes.

No matter which type of mesothelioma is suspected, biopsies are always conducted after these tests to see if cancerous cells are present in the affected area. A biopsy allows doctors to remove a sample of a tumor and then it lab tested for the presence of mesothelioma cells.

A Mesothelioma Diagnosis Video Thumbnail

Nurse Amy Fair discusses what to expect after getting a diagnosis of mesothelioma. This holistic disease affects not only the victim but the family and the caretaker too. View Transcript.

Duration: 1 min 43 sec

The most important thing folks that have been diagnosed with mesothelioma need to do is to take one minute and one day at a time. To get a diagnosis and try to fast forward about the when’s and the what’s and the how’s of what’s going to happen next month, or in six months or a year, can be very overwhelming.

When talking with families of someone that’s been diagnosed with mesothelioma, I encourage them to first let that particular person go through the stages of the feelings that they’re going to go through with this disease.

It’s important that the caregivers stay healthy too. They need to still be able to get away. They still need to be able to surround themselves with support through their family and through their church and through their friends.

Many times, when caregivers are struggling with the change of life that they are going through with this disease, I encourage them to reach out to; if they have local support groups there some of the oncologists can refer them to some local support groups. If they do not have those resources, then I do refer them directly to a mesothelioma support group.

The clients I have work with that have made the most profound impression with me are the clients that, they just needed someone to talk to and sometimes it’s not about medical, it’s not about the side effects of chemotherapy, it’s just sharing a memory of their loved one.

I get cards from them for different occasions, and there’s always a note that says that we made a difference.

Mesothelioma Imaging Tests

Doctor reviewing a chest X-ray with a patient
X-rays can reveal the initial signs of pleural and peritoneal mesothelioma.

Doctors use imaging tests to see where possibly cancerous fluids, tumors, and/or masses have formed within the body.

While the imaging tests listed below are important in the diagnosis process, the American Cancer Society (ACS) notes that more tests will be needed to confirm if someone has cancer.


An X-ray uses electromagnetic radiation to create a picture of the inside of the body. According to the ACS, X-rays are typically the first test a doctor will use to see if a patient has pleural mesothelioma.

X-rays can show:

  • Calcium deposits in the pleura (pleural plaques)
  • Fluid buildup in the lungs (pleural effusion)
  • Thickening of the lining of the lungs or abdomen
  • Other abnormalities that may indicate mesothelioma

CT Scan

Similar to X-rays, a computerized tomography (CT) scan creates a comprehensive image of the body that can locate potentially cancerous growths.

A CT scan takes numerous images and creates a computerized view of the body from multiple angles. CT scans for cancer usually require contrast to outline different organs in the body.

MRI Scan

A magnetic resonance imaging (MRI) scan is similar to a CT scan, but it uses radio and magnetic waves instead of light waves to see if cancerous tumors are present.

Patients can expect to lie inside a tube-like scanner for up to an hour while an MRI occurs.

Need help getting an accurate diagnosis?

Find top doctors in your area using our Free Mesothelioma Doctor Match.

PET Scan

A positron emission tomography (PET) scan uses a low dose of a radioactive sugar to detect cancer cells. This substance is injected into the patient’s body about one hour before the scan.

Cancer cells grow at a rapid pace and consume a larger quantity of the sugar than other cells. The PET scan can show which cells (if any) are consuming more sugar — and, in turn, may be cancerous — and where these cells are located.

The scan can also show if these cells have begun to spread throughout the body.


An echocardiogram is a specialized form of ultrasound that uses sound waves to take an image. After a gel is placed on the chest, a wand sends sound waves into the body to create a picture on a monitor.

Echocardiograms are frequently used to help confirm a pericardial mesothelioma diagnosis. A doctor may request an echocardiogram to see how well the heart is functioning or if they suspect fluid buildup around the heart.

Mesothelioma Blood Tests and Biomarkers

In addition to imaging scans, doctors can also use mesothelioma blood tests to see if cancer cells are present within the body.

A lab tech analyzing a vial of blood
SMRP tests can measure blood levels to detect the presence of mesothelioma cells.

Mesothelioma increases the levels of certain substances within the blood, including fibulin-3, soluble mesothelin-related peptides (SMRPs), and other substances. These substances can be detected through various mesothelioma blood tests.

Outside of a mesothelioma blood test, many future techniques for determining a malignant mesothelioma diagnosis are focused on biomarkers, which use substances or processes to identify abnormalities in the body.

Learn more about the different types of mesothelioma blood tests below.


The most common mesothelioma blood test is the SMRP test, which goes by its trademarked name MesoMark®. This test looks for heightened levels of SMRPs, which are substances that develop in the blood if mesothelioma cells are present.

Get our Free Survivors Guide to read stories of mesothelioma patients who credit a correct diagnosis with their ability to achieve years of survival.

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N-ERC Test

Like MesoMark, this test determines if a substance called N-ERC (mesothelin) is present within the patient’s blood.

The N-ERC mesothelioma blood test is considered more accurate than the SMRP test in identifying cancer. However, it is not as helpful when diagnosing mesothelioma specifically since the presence of N-ERC may also be a sign of other types of cancer.

Osteopontin Test

Osteopontin is a naturally occurring protein that increases when a person has mesothelioma.

An osteopontin mesothelioma blood test can determine whether a patient has cancer but does not indicate what type. Therefore, osteopontin tests that come back positive will require additional mesothelioma diagnosis testing.

MPF Test

The MPF test is a type of mesothelioma blood test used to detect the megakaryocyte potentiating factor (MPF), a protein found in the blood of mesothelioma patients. Scientists are still studying why there are high levels of MPF in mesothelioma patients.

Mesothelioma Biopsies

The only way to confirm a mesothelioma diagnosis is to perform a biopsy of tissue or fluid cells. A mesothelioma biopsy generally involves collecting a tissue or fluid sample from a possibly cancerous growth. The sample is then sent to a laboratory to be examined for cancer cells under a microscope.

Doctors look at the tissue or fluid sample under a microscope to make a definitive mesothelioma diagnosis.

Doctors typically take a fluid sample from the affected area to look for cancer cells, as fluid buildup is a common symptom of both pleural and peritoneal mesothelioma.

However, examining fluid may not be enough to conclusively diagnose mesothelioma since cancer cells may not always be present, or could look like inflammation. The ACS notes that doctors usually need a tissue sample to definitively make a mesothelioma diagnosis.

Learn more about the different types of mesothelioma biopsies below.


Doctors create a small incision in the chest and use video-assisted thoracoscopic surgery (VATS) to extract a biopsy sample. This type of mesothelioma biopsy is often preferred over others for its accuracy.

According to a study from Mansoura University in Egypt, the diagnostic accuracy rate of a slightly different thoracoscopy (called a flexi rigid thoracoscopy) reached 93.6% for 100 patients with undiagnosed pleural effusions.

Fine Needle Biopsy

A fine needle biopsy uses a long and skinny needle to collect sample cells. This type of biopsy is valued for its ability to access hard-to-reach locations in the body, such as the lungs and the heart.

Other Types of Mesothelioma Biopsies

Although thoracoscopy and fine needle biopsies are the two most common types, other techniques may be used to diagnose mesothelioma in some cases.

Additional types of biopsies include:

  • Endobronchial ultrasound needle biopsy: Doctors insert a tube down the windpipe of a sedated patient to examine the airway and collect tissue samples from the lymph nodes.
  • Laparoscopy: Doctors use a small tube with a light and camera to look inside the abdomen to locate tumors.
  • Mediastinoscopy: Doctors take a sample of the area between the two lungs (the mediastinum) if they believe the cancer has spread to nearby lymph nodes.

Mesothelioma doctors can recommend which types of biopsies will work best to confirm a diagnosis.

Challenges With Mesothelioma Diagnosis

Doctors may face several challenges when diagnosing mesothelioma in a patient. Since mesothelioma takes decades to develop and is very rare, it can take more time to accurately diagnose the disease.

Learn about these possible challenges below.

Latency Period

Mesothelioma is very unusual since it takes 10-50 years after asbestos exposure before noticeable symptoms appear.

This long latency period means that victims may not even remember being exposed to asbestos-containing products. Victims may also not suspect that their relatively mild symptoms could be caused by mesothelioma.

Patients should always tell their doctor if they were exposed to asbestos – even if their symptoms seem mild. We can help you find mesothelioma specialists in your area — use our Free Doctor Match today to get started.


Since mesothelioma symptoms can mimic those of more common diseases, it can sometimes be misdiagnosed.

For example, mesothelioma may be misdiagnosed as:

  • Bronchitis
  • Coronary artery disease
  • Chronic obstructive pulmonary disease (COPD)
  • Crohn’s disease
  • Emphysema
  • Irritable bowel syndrome (IBS)
  • Testicular infection
  • Other forms of cancer

A mesothelioma misdiagnosis can have dangerous — even deadly — consequences when it prevents a patient from accessing treatment for this type of cancer. According to a study published in the Open Epidemiology Journal, 22.6% of pleural mesothelioma cases are misdiagnosed as lung cancer.

If you believe you were misdiagnosed, you should seek a second opinion from an experienced specialist.

Get your Free Survivors Guide to learn how some mesothelioma patients were able to increase their life expectancy, even after they were misdiagnosed at first.

Mesothelioma Survivors Guide
Get Your Free Survivors Guide

7 authentic stories of mesothelioma patients who outlived their prognosis with support from loved ones

Get It Shipped Overnight

Mesothelioma Staging

Staging also presents a challenge when making a mesothelioma diagnosis. Symptoms can be mild or non-existent in the early stages of mesothelioma.

Most people are diagnosed in the later stages of mesothelioma after the symptoms have worsened. By then, chances of long-term survival are decreased since treatment options are limited and focus on palliative (pain-relieving) care.

According to the American Society of Clinical Oncology (ASCO), 13% to 16% of patients diagnosed with early-stage mesothelioma will still be alive after 5 years. By contrast, 5% to 10% of patients with late-stage mesothelioma survive 5 years after diagnosis.

Early Diagnosis: The Key to Long-Term Survival

The timing of a mesothelioma diagnosis can greatly impact your prognosis. If your cancer is diagnosed in its later stages, you may not qualify for surgery and other proven treatments.

Fortunately, there are many mesothelioma survivors who’ve beaten the odds and are still making precious memories with their families years after being diagnosed.

Get our Free Survivors Guide shipped overnight to read their stories of hope and resilience.

Mesothelioma Diagnosis FAQs

How is mesothelioma diagnosed?

Mesothelioma is diagnosed through a series of different tests. Specialists can make a mesothelioma diagnosis through imaging tests, blood tests, and biopsies.

However, a biopsy is the only definitive way to diagnose mesothelioma and other cancers.

What is the most accurate way to diagnose mesothelioma?

The most accurate testing method to diagnose mesothelioma is a biopsy. A biopsy is the only way to confirm the presence of mesothelioma.

This procedure involves collecting fluid or tissue samples from the affected area to test for cancer cells under a microscope.

Is mesothelioma difficult to diagnose?

No. While it can sometimes be mistaken for other illnesses, mesothelioma can be properly diagnosed by a skilled doctor. If you think you might have been misdiagnosed, you should get a second opinion from a specialist.

Why does it take so long to diagnose mesothelioma?

Mesothelioma has a very long latency period. It can take 10-50 years for symptoms of mesothelioma to appear after asbestos exposure.

Due to the long latency period of mesothelioma, many patients are not diagnosed until the later stages of the disease.

This is why early detection and medical intervention are important to extend life expectancy.

What should I do if I think I was misdiagnosed?

If you believe you have mesothelioma and were misdiagnosed, it is important to seek a second opinion.

Getting an accurate diagnosis is crucial to ensure you are getting the treatment you need.

Use our Free Doctor Match to find a specialist near you who can confirm your mesothelioma diagnosis.

Reviewed by:Dr. Mark Levin

Certified Oncologist and Hematologist

  • Fact-Checked
  • Editor

Mark Levin, MD has over 30 years of experience in academic and community hematology and oncology. In addition to serving as Chief or Director at four different teaching institutions throughout his life, he is also still a practicing clinician, has taught and designed formal education programs, and has authored numerous publications in various fields related to hematology and oncology.

Dr. Mark Levin is an independently paid medical reviewer.

  • Board Certified Oncologist
  • 30+ Years Experience
  • Published Medical Author
Written by:

Lead Editor

Laura Wright is a journalist and content strategist with more than 15 years of professional experience. She attended college at the University of Florida, graduating magna cum laude with a bachelor’s degree in journalism in 2008. Her writing has been featured in The Gainesville Sun and other regional publications throughout Florida.

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  2. How is MALIGNANT MESOTHELIOMA DIAGNOSED? (n.d.). Retrieved December 1, 2022, from
  3. Malignant mesothelioma STAGES. (n.d.). Retrieved December 1, 2022, from
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  7. Scharf, J., Lees, G., & Sergi, C. (2015, September 08). Malignant pleural mesothelioma in a child. Retrieved December 1, 2022, from
  8. Tests to diagnose mesothelioma. (2021, June 03). Retrieved December 1, 2022, from

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