Mesothelioma Diagnosis

  • Share this:

What Steps Lead to a Mesothelioma Diagnosis?

  1. Symptoms: Symptoms of mesothelioma cause the patient to visit their primary care physician or a hospital for testing.
  2. Mesothelioma Testing: The most common first tests are radiology exams such as chest X-rays and CT scans of the chest or abdomen. These initial tests reveal abnormal results, which lead to further testing and referral to a surgeon or oncologist.
  3. Confirm Diagnosis: The surgeon or oncologist uses a combination of imaging scans, blood tests and biopsies to confirm a mesothelioma diagnosis. A blood test or radiology scans alone cannot confirm a diagnosis of mesothelioma.
There is no clear path to a mesothelioma cancer diagnosis for every patient.
Because the disease is rare and has symptoms similar to other more common and less serious conditions, doctors sometimes confuse it for a different illness or another type of cancer. It is common for patients to be initially misdiagnosed with other conditions before receiving a mesothelioma diagnosis. Pleural mesothelioma can be misdiagnosed as pneumonia or lung cancer, and peritoneal mesothelioma may be misdiagnosed as a more common abdominal cancer.
Providing your doctor with a comprehensive work history is important to the diagnostic process. Doctors are unlikely to suspect the disease unless a patient describes a former job where asbestos exposure may have occurred. Usually, mesothelioma occurs 20-50 years after the initial asbestos exposure.

How to Test for Mesothelioma

Mesothelioma testing commonly includes imaging scans, biopsies and blood tests. Imaging scans like X-rays and CT scans identify mesothelioma tumors. A biopsy is the only definitive way to confirm a mesothelioma diagnosis. Mesothelioma blood tests are used to measure treatment response.
Imaging tests performed by radiologists reveal the location and extent of mesothelioma tumors. The “gold standard” for mesothelioma imaging is a combination CT-PET scan.

Imaging Tests Commonly Used in Mesothelioma Diagnosis

  • X-Rays: Produce basic images of areas with various densities, such as tumors or fluid, within the body.
  • CT Scans: Also known as CAT scans. These use computer software to integrate hundreds of fine X-ray images to create detailed images of internal structures. These images are much more precise than regular X-rays.
  • MRIs: Using electromagnetic technology, MRIs generate precise images, which are especially useful when looking at bone, nerve and brain tissue.
  • PET Scans: These are CT scans where the patient receives an intravenous dose of radioactive glucose, which makes inflamed cells light up on scans. Cell inflammation may be caused by an infection or rapid growth, which could be a sign of cancer.

Mesothelioma Biopsies

Biopsies are the only way to confirm a mesothelioma diagnosis. The most accurate biopsy technique for mesothelioma is called a thoracoscopy.
  • Thoracoscopy: While under general anesthesia, the surgeon inserts a small camera between the ribs to suction out the fluid, examine the appearance of the inside of the chest and take biopsies.
  • Mediastinoscopy: Also under general anesthesia, the surgeon inserts a small camera at the base of the neck to obtain biopsies of the lymph nodes around the windpipe.
  • Thoracentesis: Under local anesthesia and usually using an ultrasound probe, a small needle is inserted between the ribs in the back to remove pleural fluid buildup around the lungs. It is used to diagnose the cause of pleural effusions.
  • Fine-Needle Aspiration: Under local anesthesia, a small needle is inserted between the ribs to sample or biopsy tumors while the patient is in the CT scan machine.
  • Endobronchial Ultrasound-Guided Biopsy: According to a 2016 study, this type of biopsy is helpful at diagnosing pleural mesothelioma when other biopsy techniques can’t obtain a tumor sample.

Mesothelioma Blood Tests and Biomarkers

Mesothelioma blood tests, biomarkers and immunohistochemical markers are not accurate enough to diagnose the cancer alone. They are helpful at monitoring response to treatment.
  • MESOMARK: This FDA-approved test can detect soluble mesothelin-related peptide.
  • SOMAmer: This test can detect more than 1,000 proteins in blood serum. These proteins may have diagnostic value in identifying mesothelioma.
  • Human MPF: This test measures a protein called megakaryocyte potentiation factor.
Diagnostic Capabilities of Mesothelioma Blood Tests
TestSensitivity 1Specificity 2
Human MPF68%95%
  1. The percentage of mesothelioma patients correctly diagnosed by the test.
  2. The percentage of healthy people in which the test correctly ruled out a mesothelioma diagnosis.
How to Prepare for Mesothelioma Diagnostic Appointments
  • Assemble all necessary documents, including insurance cards and ID.
  • Make sure to discuss any asbestos exposure you may have experienced including length, time and location of exposure.
  • Bring a summary of your medical history, including details about your recent symptoms, and a list of current medications.
  • Bring something to take notes during the appointment.
  • Gather a list of questions you have for your medical team.
  • Ask a friend or family member to join you for support and assistance.
An older woman undergoing a CT-PET scan, a common tool in mesothelioma testing.
Imaging Tests, like a PET scan, can reveal tumors and are regularly used to test for mesothelioma.

How to Prepare for a Diagnostic Imaging Scan

  • You may have a light meal or snack four hours before the scan, then no food or drink by mouth. But some scans, such as a PT scan, require eight hours of fasting.
  • Take medications as usual, unless instructed otherwise.
  • Ask your doctor if your scan requires consuming liquid oral contrast before the scan and plan accordingly.
  • Research relaxation techniques if you are nervous about being in an enclosed scanning machine.
  • Plan to spend up to several hours at the appointment.
  • You’ll get the results from your doctor within a few days of the appointment.

How to Prepare for a Biopsy

  • Do not eat or drink anything six hours before your appointment.
  • Stop taking any blood thinning medication at least five days before a biopsy.
  • Wear loose clothing to the appointment.
  • Have a designated driver take you home.
  • Plan to spend several hours undergoing the biopsy. Some types of biopsies, such as a thoracoscopy, require at least a one-night stay in the hospital.
  • You may have to wait one to two weeks to get the results.

How to Prepare for a Blood Test

  • Ask how long you must fast before the blood test. Some tests require you to not eat after midnight the night before your appointment.
  • Book an early-morning appointment if you have to fast for the test.
  • Drink plenty of water, which prevents your blood pressure from dropping.
  • Plan to spend about 30 minutes at the appointment.
Depending upon the test, you may receive results instantly or within a week.

Timeline of the Diagnostic Process for Mesothelioma

Day 1:Initial symptoms, such as shortness of breath, fatigue and chest pain, are common. Although these symptoms are similar to more common conditions, such as pneumonia, heart failure or lung cancer, they will trigger your doctor to order X-rays or scans.Day 2:X-rays determine if there is fluid in the pleural cavity around the lungs which could be pneumonia.Day 3-Day 13:Physician prescribes antibiotic to treat pneumonia (10-day treatment) or drains fluid in pleural cavity. No cancer cells detected in fluid.Day 14:X-rays after treatment show lungs are clear. Doctor orders follow-up X-rays and asks patient to return in 30 days.Day 44:Follow-up X-rays show fluid buildup in pleural cavity again. Doctor either drains fluid, which may again test negative for cancer cells, or treats the pneumonia with antibiotics again (add 10 days). Doctor orders PET scans and CT scans.Day 54:Imaging scans show a possible underlying cause or recurrent pneumonia. Patient is referred to a surgeon for an appointment, which can take up to 15 days.Day 69:Surgeon schedules a biopsy appointment, which can take up to 10 days.Day 79:Surgeon takes biopsy, usually with video-assisted thoracoscopic surgery. While under general anesthesia, the surgeon inserts a small camera between the ribs to suction out the fluid, examine the appearance of the inside of the chest and take biopsies. This typically requires a hospital stay of 1-3 days. The results of the biopsies, also known as pathology, can take up to 10 days.Day 89:(Approximately three months later): Mesothelioma confirmed if biopsy tests positive for the disease.Challenges in Diagnosing Mesothelioma

Staging Mesothelioma

Staging mesothelioma is an important but challenging part of the diagnostic process. Staging defines how far the cancer has progressed, which is the biggest factor in determining which treatments are right for a patient.
Cancer stage is also a primary factor influencing a mesothelioma patient’s life expectancy.
  • Clinical staging uses imaging scans and biopsies to estimate the stage. Imaging tests, and in particular PET scans, are the best noninvasive tools doctors have for estimating the stage of mesothelioma. If the CT scan or PET scan reveals tumor spread to other organs, also known as late-stage mesothelioma or metastatic disease, a needle biopsy can be performed to prove this spread.
  • Surgical staging procedures, such as a thoracoscopy and mediastinoscopy, are minimally invasive, and they can help determine with more precision the extent of the cancer and if the cancer has spread beyond the pleural lining or into lymph nodes.


Sometimes mesothelioma is misdiagnosed as a less serious disease or another cancer. The initial symptoms of mesothelioma can resemble other conditions.
  • Pleural mesothelioma symptoms may lead to a diagnosis of pneumonia or heart failure.
  • Peritoneal mesothelioma symptoms may lead to a diagnosis of irritable bowel syndrome.
  • Pericardial mesothelioma symptoms may lead to a diagnosis of coronary heart disease.
It can also be misdiagnosed as other forms of cancer.
  • Pleural mesothelioma may be misdiagnosed as a form of lung cancer that develops in mucus-secreting glands called adenocarcinoma.
  • Peritoneal mesothelioma may be misdiagnosed as ovarian cancer or colon cancer.
Working with a nationally recognized cancer center that specializes in mesothelioma can confirm or deny the diagnosis. The doctors working at these cancer centers have the experience necessary to accurately diagnose this rare disease.
Quick Fact:
In a cytology, a doctor removes some fluid from the suspected tumor site. A pathologist then looks at the fluid under a microscope to search for cancer cells. In a biopsy, a doctor takes a tissue sample of the suspected tumor, so a pathologist can look at it under a microscope to determine if it is cancerous.
Lorraine Kember Video Thumbnail
Lorraine Kember, a former mesothelioma caregiver, describes how she felt when her husband tested positive for mesothelioma.

Latency Period

The decades-long latency period associated with asbestos-related diseases means that some patients forget they were exposed to asbestos a long time ago. They don’t mention their history of asbestos exposure, and consequently, their doctor doesn’t consider mesothelioma as a possible diagnosis.
This may contribute to a delay in diagnosis, allowing the cancer to progress without proper treatment.


When a doctor delivers a mesothelioma diagnosis, a prognosis might also be offered to the patient.
It is challenging for doctors to accurately predict the course mesothelioma will take in a patient’s body because each case is truly unique. Doctors base their prognosis on the cancer’s stage, location and cell type in addition to the patient’s age and overall health.
Some doctors chose to wait for the patient to ask about their prognosis, while others offer the prognosis right away.

Steps to Take After a Mesothelioma Diagnosis

Seek a Second Opinion

The next step after a mesothelioma diagnosis for many people is seeking a second opinion from a mesothelioma specialist. Choosing a doctor and cancer center that specializes in mesothelioma can confirm the diagnosis and get you access to innovative therapies and clinical trials.

Understand Your Treatment Plan

Another important step is thoroughly understanding your treatment plan. This is something you can discuss in detail with your oncologist. If there is any aspect of your treatment plan that makes you nervous or confused, talk to your doctor about it.
Ask about palliative care and complementary therapies that may help with side effects. For example, acupressure may help with chemotherapy-induced nausea.

Get Support

Lastly, build a mesothelioma support network to help you and your loved ones cope with this cancer. Reach out to family, friends, neighbors and community members. A strong support system will help you get through the challenges of a being diagnosed with mesothelioma.