Diagnosing Mesothelioma

Quick Summary

Doctors use a variety of tools to diagnose mesothelioma. They will examine your symptoms, then perform imaging tests (X-ray, MRI, CT)and biopsies (Needle, Tissue/Surgical)to diagnose mesothelioma. Getting an accurate diagnosis is critical to getting the best treatment.

Steps to Diagnosing Mesothelioma

The process of diagnosing mesothelioma starts with your symptoms. Most patients see their general practitioner after a couple months of symptoms. At first, your doctor may suspect a common condition like pneumonia or irritable bowel syndrome. This leads to imaging tests.

Common first symptoms of pleural mesothelioma:

  • Cough
  • Difficulty breathing
  • Fatigue
  • Chest pain
  • Shortness of breath
  • Trouble swallowing

Common first symptoms of peritoneal mesothelioma:

  • Swelling in the belly
  • Abdominal pain
  • Weight loss
  • Nausea
  • Vomiting
  • Constipation

Doctors use imaging tests to locate the source of symptoms. Imaging tests can help locate tumors in the chest and abdomen. You may find your way to see a pulmonary (lung) specialist or oncologist. Pulmonary specialists and oncologists have more experience examining symptoms and imaging tests, especially when cancer is suspected. Your pulmonary specialist may ask you about your work and military service history.

Did you know?

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

Your history of asbestos exposure can be crucial to helping doctors make a diagnosis. This history includes a description of what kind of work you did during and after the military. It is very rare to be diagnosed with mesothelioma in just one visit. Expect several visits and testing in order to make the diagnosis.

When you get the appointment with the specialist, prepare to spend up to an hour at the first consultation. Your doctor will help you pinpoint your history of asbestos exposure. Try to remember any exposures you may have had with lung-cancer inducing substances, including asbestos.

“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],” according to an editorial in the European Respiratory Journal.

Eventually, your doctor will confirm your diagnosis. You should be referred to a mesothelioma specialist at this time if you haven’t already. Your specialist may run other tests to get a more accurate picture of your diagnosis.

This helps them create a tailored treatment plan based on your specific situation. This type of specialized treatment isn’t possible without a mesothelioma specialist. Specialists may also be a part of clinical trials testing new ways of treating mesothelioma.

Difficulties with Diagnosing Mesothelioma

Mesothelioma can be difficult to diagnose. Most people don’t get diagnosed until 2-3 months after the onset of their symptoms.

Several things can get in the way of properly diagnosing this condition, including:  

  • Nonspecific symptoms. Mesothelioma symptoms are similar to those of many other diseases. Many conditions cause weight loss, cough, fatigue and chest pain. Mesothelioma is so rare that it is not the first thing doctors think of unless they know you have history of asbestos exposure.
  • Difficulty seeing on X-ray. Small areas of mesothelioma just look like thickening of the pleura (the lining of the lungs).  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. Tissue samples can look like other types of cancers under the microscope. The wrong diagnosis on a pathology report can lead to treatment that is ineffective for mesothelioma.

Imaging Studies for Mesothelioma

  • An X-ray is often the first scan doctors perform. It can show fluid buildup in the lungs or abdomen and thickening in the lining of the lungs. X-rays are most helpful for diagnosing pleural mesothelioma.
  • Computed tomography (CT) scans may be ordered of the chest, abdomen or both. CT scans take longer than X-rays. But they have 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 easier with these scans. This test is helpful locating peritoneal tumors.
  • Magnetic resonance imaging (MRI) is useful when determining how far mesothelioma has spread. It shows spreading to nearby lymph nodes and organs. A doctor may take MRI scans of the chest, abdomen or both. Like the 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. It shows cancer spreading to nearby lymph nodes and organs.
  • Positron emission tomography (PET) scans can help doctors tell the difference between scarring and cancer. Before a PET scan, patients take a radioactive protein that cancer absorbs. The PET scan finds the cells that absorbed the protein. PET scans can help find mesothelioma that has spread to distant parts of the body.
  • While CT-PET scan combination scans are felt to be the best way to diagnose mesothelioma, your cancer may be found using any of the other types of imaging tests.  

Getting a Biopsy

A biopsy is a tissue or fluid sample taken from a potentially cancerous area found on an imaging test. It may take up to a couple of weeks to get scheduled for a biopsy. It can take up to two more weeks to get the diagnosis after a biopsy has been taken. There are several ways doctors take a biopsy.

These are some ways biopsies are obtained:

  • Fine needle aspiration. 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.  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. These cancerous areas can be sampled and looked at under the microscope.
  • 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. Areas that look like cancer are sampled using small equipment associated with the laparoscope.
  • Incisional biopsy. This is also called a core biopsy. Doctors take a larger sample of the cancer but do not remove the entire cancer.
  • Excisional biopsy. In this type of biopsy, an attempt is made to remove all visible signs of cancer in the hope of curing the cancer. This is not always possible when diagnosing mesothelioma, which has often spread by the time of diagnosis.

Pathology Tests

After your doctor has obtained a biopsy, the next step is to test it. The tissue sample needs to be reviewed under the microscope by an expert pathologist.

Pathologists examine the cells found in your biopsy. They are able to determine if there are mutations among the healthy cells. This is how cancer is found. Then the pathologist notes the characteristics of the cancerous cells. Mesothelioma cells have specific traits that can be revealed by immunohistochemistry. Immunohistochemistry selectively reveals special antibodies only found on mesothelioma cells.

The pathologist might have trouble diagnosing mesothelioma because it can look like other kinds of cancer. More biopsies or further testing may be necessary to make an official mesothelioma diagnosis.

Did you know?

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.

One such test is called the MESOMARK test. The Food and Drug Administration approved it in 2007. It is a test for a proteins found on mesothelioma cells. The proteins are called soluble mesothelin-related peptides (SMRPs). People with mesothelioma often have elevated levels of SMRPs in their blood. Doctors are developing blood tests for these substances that may one day lead to earlier diagnoses.

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

The blood tests can help diagnose mesothelioma but cannot be used alone to make the diagnosis. Scans and biopsies still need to be done to show if mesothelioma is present.

Getting Diagnosed and Next Steps

Diagnosing mesothelioma is a process that requires a team of specialists. Some doctors are better at conducting imaging tests. Others are trained to take mesothelioma biopsies in a more accurate way. And there are pathologists trained to tell the difference between mesothelioma and a different type of cancer. A team of specialists like this can help ensure you get the most specific treatment for your disease.

Things to remember about your mesothelioma diagnosis:

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

Now that you have a diagnosis, you need to decide if you’re ready to accept it. Every mesothelioma patient should consider a second opinion about their diagnosis. You can be more certain about your treatment when two or more specialists agree on your treatment. A second opinion may even reveal new treatment options that prolong your survival time. Find out more about getting a second opinion now.