Nasopharyngeal Cancer: Diagnosis

Approved by the Cancer.Net Editorial Board, 06/2022

ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors use to find the cause of a medical problem. Use the menu to see other pages.

Doctors use many tests to find, or diagnose, cancer. They also do tests to learn if cancer has spread to another part of the body from where it started. If the cancer has spread, it is called metastasis. Doctors may also do tests to learn which treatments could work best.

For most types of cancer, a biopsy is the only sure way for the doctor to know if an area of the body has cancer. In a biopsy, the doctor takes a small sample of tissue for testing in a laboratory. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis.

How nasopharyngeal cancer (NPC) is diagnosed

There are many tests used for diagnosing NPC. Not all tests described here will be used for every person. Your doctor may consider these factors when choosing a diagnostic test:

  • The type of cancer suspected

  • Your signs and symptoms

  • Your age and general health

  • The results of earlier medical tests

The following tests may be used to diagnose NPC:

  • Physical examination and blood tests. During a physical examination, the doctor feels for any lumps on the neck, lips, gums, and cheeks. The doctor will look for any abnormalities in the nose, mouth, throat, and tongue, often using a light and/or mirror to get a clearer view. A blood test to check for antibodies against the EBV virus may be done at the same time. See the Risk Factors and Prevention section for more information about EBV.

  • Endoscopy. An endoscopy 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. Sedation is giving medication to become more relaxed, calm, or sleepy. 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. A pathologist then analyzes the sample(s). A pathologist is 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.

    During a fine needle aspiration, cells are removed using a thin needle inserted directly into the tumor. The cells are examined under a microscope during cytologic examination for signs of cancer. The biopsy may be performed using local anesthesia or general anesthesia. Local anesthesia is an injection that numbs the area where a procedure is being done, while general anesthesia makes a person unconscious during a major procedure, such as surgery.

  • 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 takes pictures of the inside of the body using x-rays taken from different angles. A computer combines these pictures into a detailed, 3-dimensional image that shows any abnormalities or tumors. A CT scan can be used to measure the tumor’s size. Sometimes, a special dye called a contrast medium is given before the scan to provide better detail on the image. This dye can be injected into a patient’s vein or given as a pill or liquid to swallow.

  • 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 any possible spread to nearby tissues or lymph nodes. MRI can be used to measure a tumor’s size. A special dye called a contrast medium is given before the scan to create a clearer picture. This dye can be injected into a patient’s vein or given as a pill or liquid to swallow.

  • 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 amount of radiation in the tracer is too low to be harmful. 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 lighter to the camera, and areas of injury, such as those caused by cancer, stand out on the image.

  • Neurological tests. During these examinations, the doctor tests a person’s nerve function, especially the sense of touch in their face and the motor function of certain nerves in the head and neck area.

  • Hearing test. The doctor may perform a hearing test if it seems that fluid could be in the middle ear.

  • Positron emission tomography (PET) or PET-CT scan. A PET scan is usually combined with a CT scan (see above), called a PET-CT scan. However, you may hear your doctor refer to this procedure just as a PET scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive sugar substance is injected into the patient’s body. This sugar substance is taken up by cells that use the most energy. Because cancer tends to use energy actively, it absorbs more of the radioactive substance. However, the amount of radiation in the substance is too low to be harmful. A scanner then detects this substance to produce images of the inside of the body.

After diagnostic tests are done, your doctor will review the results with you. If the diagnosis is cancer, these results also help the doctor describe the cancer. This is called staging.

The next section in this guide is Stages and Grades. It explains the system doctors use to describe the extent of the disease. Use the menu to choose a different section to read in this guide.