If a patient experiences mesothelioma symptoms, tests and procedures are performed to determine the cause. Patients should choose a doctor with experience diagnosing mesothelioma.

How is Mesothelioma Diagnosed?

Patients experiencing potential mesothelioma symptoms such as coughing, shortness of breath, or chest pains should visit a doctor. After seeing a physician, the diagnostic process determines the causes of these symptoms and a treatment plan.

Mesothelioma Diagnostic Procedures

  • Imaging Tests (X-ray, CT, PET, MRI)

    Imaging tests are used to locate tumors inside the body. Tests like X-rays, CT scans, PET scans and MRIs are commonly used to diagnose mesothelioma.

  • Blood-Marker Tests

    Doctors use a variety of blood tests in order to determine if cancer is present in patients. Doctors can also analyze the type of cancer and what treatment options work best for each patient.

  • Biopsies

    A biopsy is a tissue or fluid sample taken from a tumor or its surrounding area. These samples are examined under a microscope to determine cell type and is the only way to definitively diagnose mesothelioma.

Imaging Tests

Imaging tests are the first step in diagnosing mesothelioma. These tests show the presence of abnormalities. This helps doctors know where the tumor is and how advanced the cancer may be. Each imaging test has its own purpose, which helps specialist make an accurate diagnosis.

  • X-Ray – This test provides a 2D image of the patient and can show tumor and fluid buildup. This test is used for all suspected diagnoses (pleural, peritoneal, pericardial)
  • Computed Tomography Scan – CT scans are 3D imaging tests that provide more detailed images of anomalies found by X-rays. This is primarily used to diagnose pleural mesothelioma.
  • Positron Emission Tomography Scan – PET scans show the presence of individual cancer cells after patients are give a small dose of a radiopharmaceutical drug. This test is useful in staging.
  • Magnetic Resonance Imaging Scan – MRIs create detailed images of tissue. This test can be used to determine the extent of damage to soft tissue surrounding a tumor. This is also useful to determine if surgery is possible.

Blood Tests and Biomarkers

Blood and biomarker tests allow physicians to better diagnose the patient. These tests help determine the type of treatment that will be offered to the patient. They also aid in providing an accurate prognosis.

Doctors may decide to conduct blood marker tests in addition to imaging and biopsy tests because blood tests can provide further details about the extent of the patient’s mesothelioma. These tests work by measuring the levels of certain biomarkers, a protein for example, that are present in healthy people as well as mesothelioma patients, that can then be studied and compared. Some of the more notable blood tests are:

  • Mesomark—This FDA-approved blood test measures the level of soluble mesothelin related peptides (SMRPs) in the patient’s blood. Mesothelioma patients have higher concentrations of SMRPs.
  • Cancer Antigen 125 (CA125)—Like SMRPs, CA125 is present in healthy individuals, but mesothelioma patients have higher concentrations of the antigen. Antigens generally work with the immune system, but little is currently known about the purpose of CA125.
  • Fibulin-3—Blood tests aren’t typically known for their ability to provide an early diagnosis for mesothelioma patients. Mesothelioma is also known for being particularly hard to diagnose, but testing for the protein fibulin-3 in a patient’s blood may change this. This is still being researched.

Mesothelioma Biopsies

A biopsy is the examination of tissue or fluid extracted from the body. By examining this sample, doctors can determine if cancer cells are present. This is the only way doctors can make a conclusive diagnosis.

The histological makeup of the cancer can also be determined, which is the microscopic structure of the tissue. Certain cellular makeups respond differently to different treatment plans. There are also different types of biopsies. Tissue can be extracted through surgical biopsies, or fluid can be extracted through noninvasive biopsies.

Surgical Biopsies

Surgical biopsies are used to extract tissue from a patient. This sample of tissue is sent to a pathologist to examine for the presence of mesothelioma. This can be accomplished with traditional surgical methods or camera-assisted surgery. The various biopsy procedures are:

  • Thoracotomy – This is a traditional biopsy of the chest cavity, which is useful for pleural mesothelioma diagnosis. Surgeons can also get a firsthand look at the extent of the disease.
  • Laparotomy – This is a traditional biopsy of the abdominal cavity, which is useful for peritoneal mesothelioma diagnosis. It also allows surgeons a firsthand look at the disease.
  • Thoracoscopy – A thoracoscopy is an alternative, less invasive chest biopsy for pleural mesothelioma diagnosis taken with the help of a camera.
  • Laparoscopy – A laparoscopy is an alternative, less invasive abdominal biopsy for peritoneal mesothelioma diagnosis. The biopsy is taken with the help of a camera.
  • Mediastinoscopy – A mediastinoscopy is an alternative, less invasive chest biopsy. May be used in place of a thoracoscopy depending on the location of the tumor.

Non-Surgical Biopsies

Nonsurgical biopsies take fluid samples that built up in the lungs, abdomen or heart. A needle is used to extract the fluid which may carry cancerous cells. A cytologist examines the fluid for the presence of mesothelioma cells. This method is less invasive than surgical biopsies but is not as conclusive. It does not allow doctors a firsthand look at the tumors in a patient.

Histopathology and Cytology Reports

After a biopsy is taken, the next step is finding out if cancer is present and what type of cancer it is. Histopathology and cytology reports are used to study the tissue or fluid attained through biopsy. Histopathology reports are used for tissue biopsies and cytology reports are used for fluid biopsies.


Many doctors have never encountered mesothelioma due to its rarity. This results in a high percentage of misdiagnoses when compared to other cancers. It is commonly misdiagnosed because the symptoms are typical to illnesses such as the common cold, flu and pneumonia. To prevent misdiagnosis, patients should seek a second opinion from a separate mesothelioma specialist.

Misdiagnosis also occurs in two other ways. Mesothelioma is mistaken for other cancers including lung cancer or a number of cancers in the abdominal region. Also, mesothelioma can be staged (1-4) incorrectly, leading to limited treatment and recovery options for patients.

Alexis Kidd

Photograph of a woman

Multi-year survivor Alexis Kidd was almost diagnosed with a terminal prognosis until seeing additional specialists. They revealed that her mesothelioma diagnosis was treatable. After I was diagnosed with mesothelioma, I was actually initially staged at stage 4 because they usually do not see it on the diaphragm until it has been just about everywhere else in the chest cavity.

However, the team of doctors treating me worked hard and determined that it was not a Stage 4 and that my case was unusual. This change opened up a whole host of treatment options. Since mesothelioma is such a unique illness, many doctors don’t have the experience with diagnosing it.

For me, having it diagnosed was just the first step, and getting a second opinion gave me new options as I entered treatment.

”I am very lucky that my doctors were willing to do the necessary work, research, and collaboration in order to help me and successfully diagnose my mesothelioma.”

Alexis Kidd received her mesothelioma diagnosis but followed it up with a second opinion. She put herself in a better position by staying on top of her own health care and requiring confirmations from a specialist. Take control of your health care by getting a second opinion from a specialist today by using our free Doctor Match program.

Diagnosing Veterans – Getting a Second Opinion

Most veterans will see a general oncologist within the VA system first. Because these doctors aren’t equipped to handle a mesothelioma diagnosis, it is important that veterans using the VA get a second opinion from a mesothelioma specialist. A general oncologist may consider a veteran’s disease to be inoperable or they may suggest the wrong treatment because of a lack of experience with mesothelioma.

Many times, once a veteran sees a specialist, they learn they are eligible for more treatments than they previously thought. Additionally, there are two top mesothelioma treatment centers in the VA health system that rival the best treatment centers in the country. These centers are located at the Boston VA and Los Angeles VA. The programs are led by leading mesothelioma specialists Dr. Robert Cameron and Dr. Avi Lebenthal, respectively.

These treatment centers are the best option for veterans looking for treatment in the VA.

Treatment After Mesothelioma Diagnosis

After doctors have confirmed a diagnosis of mesothelioma, they create a treatment plan for the patient. This mesothelioma treatment plan is tailored to each patient and their unique diagnosis. Surgery may be used in patients with early stages of mesothelioma.

Chemotherapy and radiation are used in patients with any stage of mesothelioma. When a patient multiple types of treatment, it is referred to as a multimodal treatment plan. Multimodal treatment has shown promising results as surgical techniques and chemotherapy are constantly being improved.

In most cases, mesothelioma survivors have beat the odds by receiving multimodal treatment from specialists. Learn more about how they beat the odds in our free Mesothelioma Survivor’s Guide.