Doctors use many tests to diagnose cancer and find out if it has metastasized (spread). Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:
- Age and medical condition
- Type of cancer suspected
- Severity of symptoms
- Previous test results
In addition to a physical examination, the following tests may be used to diagnose thymoma or thymic carcinoma:
Biopsy . A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. The sample removed during the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease).
The type of biopsy performed will depend on the location of the cancer. A needle biopsy involves a thin needle that is inserted into the tumor to remove a piece of tissue. In some cases, depending on the location of the tumor, a surgical procedure may be necessary for diagnosis to get enough tissue for analysis. Also known as the Chamberlain procedure, this procedure is performed by making a two-inch incision next to the breastbone and removing a sample of the tumor.
Computed tomography (CT or CAT) scan . A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. A CT scan of the chest is the most common test used to look for and evaluate thymoma. A contrast medium (a special dye) is injected into a patient's vein to provide better detail. Magnetic resonance imaging and positron emission tomography (see below) may provide additional information but are not always needed.
Magnetic resonance imaging (MRI) . An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. A contrast medium may be injected into a patient's vein to create a clearer picture.
Positron emission tomography (PET) scan . A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive substance is injected into a patient's body. This substance is absorbed mainly by organs and tissues that use the most energy. Because cancer tends to use energy actively, it absorbs more of the radioactive substance. A scanner then detects this substance to produce images of the inside of the body.
Learn more about what to expect when having common tests, procedures, and scans .
After these diagnostic tests are done, your doctor will review all of the results with you. If the diagnosis is cancer, these results also help the doctor describe the cancer; this is called staging . Learn more about the first steps to take after a diagnosis of cancer .