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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
The following tests may be used to diagnose NPC:
Physical examination and blood test. The doctor feels for any lumps on the neck, lips, gums, and cheeks. Also, the doctor will inspect the nose, mouth, throat, and tongue for abnormalities, often using a light and/or mirror for a clearer view. A blood test to check for antibodies against the EBV virus (see Risk Factors) may be done at the same time.
Endoscopy. This test allows the doctor to see inside the body with a thin, lighted, flexible tube called an endoscope. The person may be sedated as the tube is inserted through the mouth or nose to examine the head and neck areas. When an endoscopy is done to look into the nasopharynx, it is called a nasopharyngoscopy.
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 from 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. In a fine needle aspiration biopsy, cells are withdrawn using a thin needle inserted directly into the tumor. The cells are examined under a microscope for signs of cancer (called cytologic examination). The biopsy may be performed using local anesthesia (medication to block awareness of pain) or general anesthesia.
X-ray. An x-ray is a way to create a picture of the structures inside of the body, using a small amount of radiation. Sometimes, a barium swallow may be required before having an x-ray. The barium coats the mouth and throat to enhance the image on the x-ray. An x-ray of the skull and chest may be needed to learn more about the extent of NPC.
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. Sometimes, a contrast medium (a special dye) is injected into a patient’s vein to provide better detail.
Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body, especially images of soft tissue, such as the tonsils and base of the tongue. An MRI is more sensitive than a CT scan in detecting a tumor of the nasopharynx and its possible spread to nearby tissues or lymph nodes. A contrast medium may be injected into a patient’s vein to create a clearer picture.
Ultrasound. An ultrasound uses sound waves to create a picture of the internal organs.
Bone scan. A bone scan uses a radioactive tracer to look at the inside of the bones. The tracer is injected into a patient’s vein. It collects in areas of the bone and is detected by a special camera. Healthy bone appears gray to the camera, and areas of injury, such as those caused by cancer, appear dark.
Neurologic tests. These examinations involve the doctor testing nerve function, especially tactile sensation of the face and motor function of certain nerves in the head and neck area.
Hearing test. The doctor may perform a hearing test if he or she suspects there is fluid in the middle ear.
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.