A variety of methods is used to diagnose salivary gland cancer. They include:

• Physical exam and history

After a physical exam that reveals cause for suspicion of salivary gland cancer, imaging tests may be ordered to determine the extent of spread of the tumor, if any. Standard imaging tests include:

• Magnetic resonance imaging (MRI): A procedure that uses a magnet, radio waves and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear MRI , or NMRI.
• CT (computed tomography) scan: A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an X-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computerized tomography or computerized axial tomography.
• Positron emission tomography (PET) scan: A procedure to find malignant tumor cells in the body. A small amount of a radioactive glucose derivative (fluorodeoxyglucose) is injected into a vein. The PET scanner rotates around the body and generates a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.
• Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.
• Endoscopy:A procedure to look at organs and tissues inside the body to check for abnormal areas. For salivary gland cancer, an endoscope is inserted into the mouth to look at the mouth, throat and larynx. An endoscope is a thin, tube-like instrument with a light and a lens for viewing.

After identifying the primary site or sites of the tumor, a biopsy may be ordered, as detailed below:

• Fine needle aspiration biopsy: The removal of tissue or fluid using a thin needle. A pathologist views the tissue or fluid under a microscope to look for cancer cells. This test is necessary to establish three things:  1) whether the tumor is benign or malignant, 2) what type of cell the tumor originated from and 3) what grade, or level of differentiation, the tumor cells display.