There are a number of ways to properly diagnose mesothelioma, with the most effective being a surgical biopsy. There are other less invasive ways as well, including needle biopsy and cytology.
The Mesothelioma Diagnostic Process
Mesothelioma can be difficult to diagnose. There are several things that get in the way of properly diagnosing this condition. These include:
- Nonspecific symptoms. Mesothelioma symptoms are similar to those of many other diseases and, for several months, you can just feel poorly. Weight loss, cough, fatigue, and chest pain can mean many things and mesothelioma is rare enough that it is not the first thing doctors think of unless they know of a 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, and may instead require a CT or MRI scan of the chest to see the areas of cancer.
- Difficulty getting an accurate biopsy. Even when cancer is suspected, tissue samples often 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.
Once cancer is suspected, there are several ways to diagnose mesothelioma, including X-rays, scans, biopsies and specific blood tests. The doctors need to suspect mesothelioma before many of these techniques for diagnosing the disease can be helpful.
This is why it is so important to document and remember your past history of asbestos exposure, which could have been when you were in the armed forces many decades ago. Most individuals with mesothelioma don’t get the diagnosis officially until 2-3 months after the onset of their symptoms. At this point, the cancer may have spread to other body areas.
If you know you have a history of exposure to asbestos, it is important to find a mesothelioma specialist who understands best how to reach the diagnosis and finally treat the disease, hopefully in the earliest stages of mesothelioma.
Steps to Diagnosing Mesothelioma
In general, even those exposed to asbestos do not get screened with chest X-rays or abdominal X-rays in order to find the cancer before symptoms arise. Once symptoms arise, the patient at risk for mesothelioma usually contacts their regular doctor, who may or may not know how to diagnoses mesothelioma.
Eventually, you may find your way to see a pulmonary (lung) specialist. This person usually has more experience with mesothelioma and will be able to do more invasive testing to try and find a sample of the cancer to test for mesothelioma and other lung or peritoneal cancers. You may also be referred to a cancer specialist, called an oncologist, who can help make a mesothelioma diagnosis.
The tissue sample needs to be reviewed under the microscope by an expert pathologist. The pathologist might misdiagnose mesothelioma because it looks like other kinds of cancer. More biopsies or further testing may be necessary to make an official mesothelioma diagnosis.
The history of asbestos exposure can be crucial in helping the doctors look specifically for mesothelioma. If you worked in the military in areas of shipbuilding, naval shipyards, construction, or were an asbestos miner, the doctor is more likely to go straight to specific tests for mesothelioma, increasing the chances of finding it at an early stage. Veterans especially have an increased risk of getting mesothelioma due to asbestos exposure in the military.
The oncologist may or may not be skilled in the treatment of mesothelioma. You may be referred or may ask to see a mesothelioma specialist who knows the latest treatments for the disease and who may be a part of clinical trials that are trying to determine better ways of treating mesothelioma. Being in a clinical trial may increase your length of survival from this disease because newer and better treatments are being tried out in a clinical setting.
All of these steps take time, which is why the diagnosis of mesothelioma often takes 2-3 months. If your symptoms are really vague, you may not even seek medical attention until you have had them for several weeks or months.
The Mesothelioma Consultation
When you see the pulmonologist or oncologist, it means that your primary doctor suspects cancer of the lungs. When you get the appointment with the specialist, be prepared to spend up to an hour at the consultation. Try to remember any exposures you may have had with lung-cancer inducing substances, including asbestos. Give the doctor your complete work history, including a description of what kind of work you did in the military. It is very rare to be diagnosed with mesothelioma in just one visit, no matter how good the doctor is or how high the chances are of having mesothelioma. Expect several visits and testing in order to make the diagnosis.
Imaging Studies for Mesothelioma
- An X-ray can show thickening of the pleural lining, fluid in the abdominal cavity or fluid in the lung cavity. A sample of the fluid might or might not show mesothelioma cells. When the fluid is removed and a mesothelioma diagnosis is made, the fluid will likely come back, giving the doctor another chance to find cancer cells within the fluid.
- A CT scan may be ordered of the chest, abdomen, or both. CT scans use X-ray energy and a computer to create cross-sectional pictures of the organs inside the body. CT scans are considered better tests for the diagnosis of mesothelioma than standard X-rays.
- An MRI scan of the chest, abdomen, or both may be ordered. 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. Areas of cancer will often show up on this type of scan.
- A PET scan may also be ordered. It uses radioactive sugar to identify areas of the abdomen or lungs that have high metabolic activity. Cancers naturally have higher metabolic activity than normal tissue and show up on a PET scan.
- 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. Many of these scanning techniques require you to lie still for a long period of time in an enclosed area. Be prepared for that by understanding that relaxation techniques can make it easier to tolerate having the test.
Getting a Biopsy
If an area of possible cancer is found on a scan, a biopsy is scheduled. It may take up to a couple of weeks to get scheduled for a biopsy and up to two weeks more to get the diagnosis after a biopsy has been taken. There are several ways to have a biopsy. During a biopsy, a sample of tissue is taken from the area suspected of being cancerous.
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. The cells can be looked at under the microscope so the diagnosis of cancer is obtained.
- Thoracoscopy. In this test, 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 thorocoscopy, except that 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 abdomen where cancer is looked for. 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.
Blood Tests for Mesothelioma
Because of recent research, blood tests called biomarker tests have been found effective in mesothelioma patients. One such test is called the MESOMARK test. It is a test for a protein found on mesothelioma cells. There are other blood tests that have been found to show mesothelioma. These include:
- SOMAmer Panel
- Human MPF ELISA Kit.
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. The three main tests for mesothelioma are all very specific for mesothelioma, meaning that, if the test is positive, you likely have the disease. They aren’t as sensitive for mesothelioma, however, and can be negative even when mesothelioma is present. Some doctors use these tests in order to see how treatment methods are working to reduce the number of mesothelioma tests inside the body.