Thymus Cancer: Diagnosis
If your healthcare provider thinks you might have a thymus tumor, you'll need certain exams and tests to be sure. Diagnosing a thymus tumor starts with your healthcare provider asking you questions. You'll be asked about your health history, your symptoms, risk factors, and family history of disease. A physical exam will also be done.
What tests might I need?
If your provider thinks you might have thymus cancer, you will need one or more of the following tests:
Imaging tests can be used to look for a thymus tumor.
If your healthcare provider thinks you have a problem in the middle of your chest, an X-ray is usually the first test done. It can often show tumors in the thymus, nearby organs, or lymph nodes.
For this test, you lie on a table as it slides through a ring-shaped CT scanner. The scanner takes many X-rays. Then a computer combines these images to make pictures of your insides. CT scans show much more detail and can show smaller changes than chest X-rays.
MRIs use radio waves and magnets instead of X-rays to create very detailed images of the inside of your body. You may have this test if you can't have a CT scan for some reason. MRI is also very good for looking for cancer spread to the brain or spinal cord.
Positron emission tomography (PET) scan
For this test, you’re injected with a slightly radioactive sugar. Cancer cells collect more of the sugar than normal cells. After about an hour, a special camera is used to take a picture of your whole body. It show where the radioactive sugar has collected. These spots might be cancer.
The images from PET scans are not as detailed as those from CT scans. Some machines can do a PET scan and CT scan at the same time. This test is useful if your provider thinks the cancer may have spread but isn't sure where.
Blood tests aren't used to diagnose thymus tumors. But they can sometimes help diagnose other problems and get a general idea of your overall health. For instance, your healthcare provider may do blood tests to look for antibodies in your blood. These can sometimes be found in people with myasthenia gravis or other autoimmune disorders linked to thymus tumors.
If your healthcare provider sees a thymus tumor on an imaging test, he or she will decide if it can be removed. If it can be, the next step is often surgery to take out the tumor.
In some cases, the diagnosis isn't clear on the imaging tests, or the whole tumor can't be removed. When this happens, your healthcare provider may take out a tiny piece (called a sample) of the tumor during a biopsy. A doctor who specializes in looking at cells, called a pathologist, then looks at the samples under a microscope to see if there are cancer cells in them.
For this test, a thin, hollow needle is put through your skin and into the tumor to get a sample of it. This is often done during a CT scan of your chest. This allows your healthcare provider to watch the needle go into the tumor and be sure the sample comes from the right place. Sometimes a needle biopsy doesn't get enough tissue to make a clear diagnosis.
Surgery can be done to do a biopsy. A 2-inch cut is made next to the breast bone (sternum) so a piece of the tumor can be removed. This is more involved than a needle biopsy. But it’s also more likely to provide a large enough sample for diagnosis. You may hear this called the Chamberlain procedure.
Getting your test results
When your healthcare provider has the results of your tests, he or she will contact you. Your provider will talk with you about other tests you may need if a thymus tumor is found. Make sure you understand the results and what follow-up you need.