Mesothelioma Tests & Diagnosis

If you believe you have been exposed to asbestos, you may be wondering if there are medical tests that are able to tell whether or not you are at risk for mesothelioma or asbestosis.

The answer is yes – and no. In the first place, virtually everyone in the U.S. today has been exposed to asbestos to some degree. Asbestos is a collection of naturally-occurring silicates, similar to stone. Asbestos particles are present in the air we breathe, albeit in very low concentrations (less than one part per million).

If you suspect that you have been exposed to high levels of asbestos, there are several ways to confirm it. Asbestos exposure can be measured by analysis of the urine, feces, mucous or lung washings (the lungs are literally washed out with a saline solution). Unfortunately, there is no way to determine whether or not a patient will actually contract a disease from such exposure.

Early Symptoms and Detection

In order to confirm whether or not mesothelioma is present during its earliest stages (Stage I, “localized”), a thorough physical exam and special diagnostic tests are required, in addition to chest x-rays and CAT scans (1).

In its earliest stage, mesothelioma manifests itself as a series of tiny bumps on the surface of the pleura – the membrane that surrounds the lungs. These tiny bumps are called nodules, and typically, they do not show up in x-rays until the disease has reached a more advanced stage at which point they have become substantially larger.

As with many respiratory diseases, mesothelioma causes chest pains and breathlessness, as well as a nagging, persistent cough and corresponding hoarseness of the voice. In its peritoneal (abdominal) form, mesothelioma can cause abdominal pain and swelling.

In addition to these specific symptoms, mesothelioma produces more generalized symptoms that are common to many different cancers and related illnesses. Night sweats, unexplained weight loss, chronic fatigue and loss of appetite may be due to any number of pathogenic conditions.  It requires a battery of specialized tests to determine the specific cause (2).

If you believe your symptoms are indicative of something more serious, your first step is to schedule a full physical examination with your family’s primary care physician. S/he will need to know your entire medical and occupational history before proceeding. Urinalysis will be performed, and if there appears to be unusual noises in the respiratory system or tests show diminished lung capacity, your physician may order a chest x-ray. If this x-ray shows any abnormalities, you will be referred to a specialist, who may order a CT scan.

Advanced Diagnostic Techniques

The CT, or Computerized Tomography scan is a series of x-rays, taken from different angles so as to create a 3-dimensional picture of the internal organs. Generally lasting thirty minutes or less, a CT scan involves a small amount of radiation exposure, but not enough to be health-threatening.

If you are scheduled for a CT scan, the specialist will instruct you to refrain from eating and drinking for at least four hours prior to the procedure. Immediately prior to the scan, you may be given an injection of an iodine-based dye that will make certain parts of your internal anatomy more visible in the scan. There are side effects associated with this – usually consisting of a feeling of heat throughout your body. If you are asthmatic or allergic to iodine, it is vital to give the physician this information prior to the CT scan.

Thickening of the pleura and peritoneum and excess fluid in the chest and abdominal cavities will become apparent in a CT scan. However, these can be symptoms of any number of disorders. Determining whether or not mesothelioma is the cause require additional tests.

One of these tests is called pleural or peritoneal aspiration. This procedure involves the insertion of a special kind of needle syringe into the chest or abdomen, which is then used to draw fluid. Again, chances are that you as the patient will be sedated before this is done; it is really quite painless.

Once a sample of this fluid has been obtained, it undergoes a lab analysis to determine whether or not it contains cancerous cells.

A biopsy is another diagnostic method for determining if cancer is present. This is the process of obtaining an actual tissue sample from the area in question. While the patient is under general anesthesia, the oncologist will pass a small tube through the skin of your chest or abdomen, which has a miniature light and camera mounted at the end. This device is called the endoscope. It is used to collect a small tissue sample, which is then examined by a pathologist in the lab under a microscope.

Even under examination, the oncologist may not be able to make a final determination as to the nature of your illness. The sample may be sent off for examination by other labs in order to confirm your oncologist’s diagnosis. In some cases, tests may need to be re-done, or you will be advised to seek a second opinion. In any event, test results may take several days.

What To Do In The Meantime

During this time, it will be natural for you to feel apprehensive. It may be helpful to share your feelings; if you are not comfortable talking to a friend or family member, you may wish to consider contacting one of the many cancer support groups in your community or online. The National Cancer Institute at 1 (800) 4CANCER can put you in touch with such a support group. In addition, they have cancer specialists on duty from 9 AM to 4:30 PM Eastern Time, Monday through Friday to answer any questions or respond to any concerns you may have (3).

'Mesothelioma Tests & Diagnosis' Resources:
  1. Agency for Toxic Substances and Disease Registry. “ToxFAQs™
    for Asbestos    ”.  Department of Health and Human Services. September 2001.
  2. Cancerbackup. “Symptoms of Mesothelioma”. Cancerbackup.org.uk. February 28, 2006.
  3. National Cancer Institute. “Support and Resources.”