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Mesothelioma Diagnosis

A biopsy is the only definitive way to diagnose mesothelioma. However, doctors may also use imaging tests, blood tests, and physical exams to rule out other conditions and get a complete picture of your overall health. The team at Mesothelioma Hope can help you prepare for these tests and figure out what to do next if you’re diagnosed.

Medically reviewed by: Mark Levin, MD

Last updated:

Key Facts on Diagnosing Mesothelioma

  • Mesothelioma can be misdiagnosed — it’s a rare cancer with symptoms that can be mistaken for other illnesses.
  • Getting a second opinion from a mesothelioma specialist can help ensure you’re properly diagnosed and know what treatment options are available to you.
  • Diagnostic testing costs depend on your insurance and other factors. If you’re concerned about paying for testing, we can help you pursue financial assistance.
  • If you’ve been diagnosed with mesothelioma, the next step is to find a mesothelioma doctor if you don’t have one already.

How Is Mesothelioma Diagnosed?

To get an accurate mesothelioma diagnosis, you’ll need to see a specialist. Your primary care doctor or general oncologist may not have the expertise to diagnose and treat this rare cancer, so it’s crucial to find a specialist to help you.

The basic steps for a mesothelioma diagnosis include:

  1. Symptom evaluation. During your initial exam, the mesothelioma doctor will ask about your symptoms to get a full picture of your health. It’s important that you share everything you’ve noticed, such as fatigue, weight changes, pain, and any respiratory changes.
  2. Medical and personal history. Your doctor will also want to know about your medical history, including any existing health conditions and risk factors, like whether you might have been exposed to asbestos (the only known cause of mesothelioma).
  3. Testing. Depending on your symptoms, your doctor may order blood tests and imaging scans to look inside your lungs and abdomen. These tests will help your doctor rule out other conditions and better understand your health.
  4. Biopsy. The only way to confirm a mesothelioma diagnosis is through a biopsy. During a biopsy, a pathologist (a type of doctor who studies diseases) examines fluid or tissue samples under a microscope for cancerous cells.

Some patients are diagnosed with mesothelioma during surgery or treatment for another condition.

If you are looking for a doctor who can help with diagnosing mesothelioma, offering a second opinion, or developing a care plan for you or a loved one, use our Free Doctor Match to find a specialist near you.

Mesothelioma doctor talking with an older couple
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Mesothelioma Testing by Symptoms & Cancer Type

Doctors use specific techniques and equipment to make a mesothelioma diagnosis depending on the patient’s symptoms and where in the body their cancer may be located.

Learn about the common tests used to diagnose each type of mesothelioma below.

Pleural Mesothelioma

This type of mesothelioma is located in the lining of the lungs, also known as the pleura.

Common symptoms of pleural mesothelioma include chest pain, coughing, shortness of breath, and fatigue. Doctors use different tests to determine if cancer is present in the pleura, whether it has spread, and whether the lungs have been weakened.

Common pleural mesothelioma tests include:

  • Computed tomography (CT) scans
  • Magnetic resonance imaging (MRI) scans
  • Positron emission tomography (PET) scans
  • Pulmonary function tests (lung function tests)
  • X-rays

”They did a CAT scan. Then we went in for the results. That’s when the doctor just said, ‘You have stage four mesothelioma, John.’ We were shocked.”

Dee Stahl, wife of stage 4 mesothelioma survivor John Stahl

Peritoneal Mesothelioma

This type of mesothelioma is located in the peritoneum, or lining of the abdomen.

Common symptoms of peritoneal mesothelioma include abdominal pain, bloating, constipation, loss of appetite, nausea, and vomiting. Doctors use several tests to determine if cancer is present in the peritoneum and whether it has spread beyond the abdominal cavity.

Common peritoneal mesothelioma tests include:

  • Biopsies
  • Blood tests
  • CT scans

Learn more about the symptoms and diagnostic process for both pleural and peritoneal mesothelioma in our Free Mesothelioma Guide. This helpful, informational packet is shipped overnight to your front door.

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Biopsies for a Mesothelioma Diagnosis

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

Fluid may be drawn from around the lungs or abdomen, but the American Cancer Society (ACS) notes that doctors usually need a tissue sample to make a definitive mesothelioma diagnosis.

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

Types of mesothelioma biopsies include:

  • Thoracoscopy. Doctors create a small incision in the chest and use VATS (video-assisted thoracoscopic surgery) to extract a biopsy sample. This type of biopsy is highly accurate and is one of the preferred methods of diagnosing malignant pleural mesothelioma.
  • Fine needle biopsy. A fine needle biopsy collects sample cells using a long and skinny needle. Doctors can use it to access hard-to-reach locations in the body, such as the lungs and the heart.

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 biopsy procedures 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.

Your doctor will determine which type of biopsy will work best to confirm your diagnosis.

Mesothelioma Imaging Scans

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

Doctors use imaging scans to see where possibly cancerous fluids, tumors, or masses have formed within the body. These tests are often used early in the diagnostic process to rule out other conditions.

Common types of imaging scans include:

  • X-rays. 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 order for pleural mesothelioma.
  • CT scans. A computed tomography (CT) scan creates a more detailed and comprehensive image of the body than an X-ray to locate potentially cancerous growths.
  • MRI scans. A magnetic resonance imaging (MRI) scan is similar to a CT scan, but it uses radio waves and magnets instead of X-rays to highlight possible tumors.
  • PET scans. A positron emission tomography (PET) scan uses a low dose of radioactive sugar to detect cancer cells. Your doctor may use this scan to see if the cancer has spread to your lymph nodes or other parts of the body.

Mesothelioma Blood Tests and Biomarkers

Mesothelioma increases the levels of certain proteins and molecules in the blood, such as fibulin-3 and soluble mesothelin-related peptides (SMRPs). These substances can be detected through various mesothelioma blood tests as ordered by your oncology (cancer) doctor.

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

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

  • SMRP test. The most common mesothelioma blood test is the SMRP test (MESOMARK®). This test looks for heightened levels of SMRPs, substances that develop in the blood if mesothelioma cells are present.
  • N-ERC test. This test can determine if a substance called N-ERC (mesothelin) is present in the patient’s blood. While the N-ERC test is more accurate than the MESOMARK test, it’s less effective at ruling out mesothelioma since it can detect a variety of other cancers.
  • 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.
  • MPF test. This can detect megakaryocyte potentiating factor (MPF), a protein found in the blood of mesothelioma patients.

Your doctor may also order blood tests to get an idea of your overall health, such as kidney and liver function. This will help them establish a treatment plan for your specific situation.

Mesothelioma can’t be diagnosed with blood tests alone, so they are used less frequently than imaging scans and biopsies.

Mesothelioma Diagnosis Stories

Each person’s medical journey is unique, but hearing how other mesothelioma patients were diagnosed can help you see the different paths to treatment.

Below, learn what symptoms led three mesothelioma patients to seek medical care, the tests they underwent, and how they were diagnosed.

pleural mesothelioma survivor John Stahl with his wife

John Stahl

  • Initial symptoms: Fatigue, shortness of breath, feeling off
  • Appointments: Urgent care center, primary care visit, and then referred to an oncologist
  • Tests: X-ray of lungs followed by CT scan

John was diagnosed with stage 4 pleural mesothelioma. Read John’s full story here

peritoneal mesothelioma survivor Alexis Kidd with her husband

Alexis Kidd

  • Initial symptoms: Abdominal pain
  • Appointments: Unrelated gallbladder surgery
  • Tests: Tissue biopsy from diaphragm

Alexis was diagnosed with peritoneal mesothelioma. Read Alexis’s full story here

pleural mesothelioma survivor John Panza

John Panza

  • Initial symptoms: Flu-like symptoms
  • Appointments: Doctor visit and two thoracentesis procedures to remove fluid around the lungs that kept returning
  • Tests: Chest X-ray, which found pleural effusions (fluid collection), followed by VATS (video-assisted thoracoscopic surgery)

John was diagnosed with stage 3 pleural mesothelioma. Read John’s full story here

Challenges With Getting a Mesothelioma Diagnosis

Since mesothelioma takes decades to develop and is very rare, it can take longer to diagnose it accurately. In some cases, mesothelioma is diagnosed during treatment for other conditions or isn’t diagnosed until other possibilities are ruled out.

Latency Period

It can take 10-50 years after asbestos exposure before noticeable symptoms of mesothelioma appear.

This long latency period (the time between asbestos exposure and a malignant mesothelioma diagnosis) means that patients may not even remember being exposed to asbestos-containing products.

Patients may also not suspect that their relatively mild symptoms could be caused by mesothelioma.


Since mesothelioma symptoms can mimic those of more common diseases, it’s possible to be misdiagnosed.

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, like lung cancer

A mesothelioma misdiagnosis can occur when mesothelioma is incorrectly diagnosed as a different condition or when the diagnosis is not the right stage or cell type.

Getting a second opinion from an experienced specialist can help ensure you have the correct mesothelioma diagnosis and can receive the most effective treatments. Use our Free Doctor Match to find a specialist near you for a second opinion.

Mesothelioma doctor talking with an older couple
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What to Do After a Mesothelioma Diagnosis

If you or a loved one were diagnosed with mesothelioma, take a moment to process this news and your feelings — you won’t solve everything right away. It’s important to understand your diagnosis and determine what steps to take to get the treatment you need.

”If there’s a wait to see a mesothelioma specialist, take that time. Take that time to get your nutrition in check. Take that time to do all the things you need to do at home. Don’t focus on the wait time, because your cancer’s not inside you going crazy in that one month or six-week time frame.”

Amy Fair, RN, Patient Advocate

A few things to consider after a mesothelioma diagnosis include:

  1. Getting a second opinion
  2. Finding a mesothelioma specialist who can develop a custom treatment plan for you
  3. Asking about alternative treatment options and clinical trials

It can also be helpful to join a support group or connect with a therapist to help you navigate the mental and emotional aspects of a mesothelioma diagnosis and treatment.

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.

Get Help With a Mesothelioma Diagnosis

Wherever you are in your mesothelioma journey, you are not alone. Mesothelioma Hope is committed to walking alongside you every step of the way.

Our Patient Advocates are here to:

  • Connect you with a mesothelioma specialist for a diagnosis or a second opinion
  • Empower you with information and questions to ask your cancer care team
  • Help you navigate your insurance to understand what tests will be covered
  • Walk you through what to expect during different scans and procedures

Call us any time at (866) 608-8933 or use our Free Doctor Match service to get started.

Diagnosing Mesothelioma FAQs

How do I know if I have mesothelioma?

The only way to know for sure whether you have mesothelioma is to get diagnosed by a mesothelioma doctor.

Tests used to diagnose mesothelioma include imaging scans like X-rays and CT scans, biopsies, and blood tests.

If you’re experiencing mesothelioma symptoms or suspect that you were exposed to asbestos, you should reach out to a doctor right away for a physical examination.

How is mesothelioma diagnosed?

Doctors diagnose mesothelioma through a series of different tests, including an initial physical exam, imaging scans, blood tests, and biopsies.

A biopsy is the only definitive way to diagnose mesothelioma and other cancers.

Is there a test for mesothelioma?

Yes, there are several different tests used to diagnose mesothelioma, including biopsies, imaging scans, and blood tests.

MESOMARK® is a blood test that is used to monitor elevated levels of soluble mesothelin-related peptides (SMRPs), which may indicate the presence of mesothelioma.

Does mesothelioma show up on an X-ray?

Yes, chest X-rays may be one of the first tests used to diagnose pleural mesothelioma.

Chest 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

While an X-ray can help identify the need for further testing, a biopsy is the only way to confirm a mesothelioma diagnosis.

Is mesothelioma hard to diagnose?

There are some unique challenges to diagnosing mesothelioma, but a skilled specialist will know what tests to run to get you the answers you need.

Mesothelioma can sometimes be mistaken for other illnesses, so if you think you might have been misdiagnosed, you should get a second opinion from a specialist.

What should I do if I think I was misdiagnosed?

You should get a second opinion if you believe you were misdiagnosed. An accurate diagnosis is crucial to ensure you get the treatment you need to improve your life expectancy.

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

Dr. Mark LevinReviewed by:Mark Levin, MD

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 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
Jenna TozziWritten by:

Director of Patient Advocacy

Jenna Tozzi, RN, is the Director of Patient Advocacy at Mesothelioma Hope. With more than 15 years of experience as an adult and pediatric oncology nurse navigator, Jenna provides exceptional guidance and support to mesothelioma patients and their loved ones. Jenna has been featured in Oncology Nursing News and is a member of the Academy of Oncology Nurse & Patient Navigators & the American Nurses Association.

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  1. American Cancer Society. (2018, November 16). How is Malignant Mesothelioma Diagnosed? Retrieved May 28, 2024, from
  2. American Cancer Society. (2018, November 16). Malignant mesothelioma Stages. Retrieved May 28, 2024, from
  3. Cancer Council Victoria. (August 2021). Mesothelioma. Retrieved May 28, 2024, from
  4. Cancer Research UK. (2023, June 30). Tests to diagnose mesothelioma. Retrieved May 28, 2024, from
  5. El-Hadidy, T., & Rezk, N. (2015, November 12). Diagnostic accuracy and safety of rigid MEDICAL Thoracoscopy In undiagnosed pleural EFFUSION and ILD: Retrospective study of 100 patients. Retrieved May 28, 2024, from
  6. Mayo Clinic. (2020, October 20). Mesothelioma – Diagnosis. Retrieved May 28, 2024, from
  7. NHS. (2018, August 1). Laparoscopy (keyhole surgery). Retrieved May 28, 2024, from
  8. Scharf, J., Lees, G., & Sergi, C. (2015, September 8). Malignant pleural mesothelioma in a child. Retrieved May 28, 2024, from
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