Diagnosis of Salivary Gland Cancer
To diagnose salivary gland cancer, the doctor will ask about your medical history and potential risk factors. Then he or she will do a careful physical examination. A thorough examination of the skin is particularly important if you have ever had a skin tumor. If there is facial nerve paralysis, specific tests will be necessary, and an examination of the oral cavity (mouth), hypopharynx (lower throat), and larynx (voice box) will also be done.

There are no specific blood or urine tests that can detect a salivary gland tumor because there are no known tumor markers for salivary gland cancer at this time. Tumor markers are substances found in higher-than-normal amounts in the blood, urine, or body tissues of people with certain kinds of cancer.

In addition to a physical examination, the following tests may be used to diagnose salivary gland cancer:

Ultrasound-guided needle biopsy. During this type of biopsy, the doctor uses the images produced by an ultrasound to guide a needle into the tumor. An ultrasound uses sound waves to create a picture of the internal organs. 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.

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).

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 while the tube is inserted through the mouth, down the esophagus, and into the stomach and small bowel. The examination has different names depending on the area of the body that is examined, such as laryngoscopy (larynx), pharyngoscopy (pharynx), or a nasopharyngoscopy (nasopharynx). Sedation is giving medication to become more relaxed, calm, or sleepy.

Computed tomography (CT or CAT) scan. A CT scan creates a 3-dimensional picture of the inside of the body using x-rays taken from different angles. A computer combines these images into a detailed, cross-sectional view 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 person's vein or given as a 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. MRI can be used to measure the 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 person's vein or given as a pill or liquid to swallow.

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 a person'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. A scanner then detects this substance to produce images of the inside of the body

Panoramic radiograph. Also called a Panorex, this is a rotating, or panoramic, x-ray of the upper and lower jawbones to detect cancer or evaluate teeth before cancer treatment. This x-ray is not generally used to evaluate salivary gland tumors because it mostly evaluates only bone and teeth structures.