How is salivary gland cancer diagnosed?

Salivary gland cancer is most often diagnosed when a patient goes to a doctor because of symptoms.

Signs and symptoms of salivary gland cancer

The major salivary glands are located on the sides of the face and below the tongue. Several important nerves and other structures run through or near salivary glands and can be affected by salivary tumors. Possible signs and symptoms of salivary gland cancer include:

• A mass or lump in your face, neck, or mouth
• Ongoing pain in one place in your face, neck, or mouth
• A newly noticed difference between the size and/or shape of the left and right sides of your face or neck
• Numbness in part of your face
• New weakness of the muscles on one side of your face
• Trouble swallowing

These are symptoms and signs of salivary gland cancer, but they may also be caused by other conditions. Still, if you have any of these problems, it's important to see your doctor right away so the cause can be found and treated, if needed.

Medical history and physical exam

If you have any signs or symptoms that suggest you might have a salivary gland tumor, your doctor will want to take a complete medical history to check for symptoms and risk factors, including your family history.

Medical history

The first step is to take your complete medical history, in which the doctor asks you questions about risk factors and symptoms that might suggest salivary gland cancer. You will also be asked about your general health.

Physical exam

A physical exam provides information about your general health, possible signs of salivary gland cancer, and other health problems. During your physical exam, your doctor will carefully examine your mouth and the areas on the sides of your face and around your jaw, and will look for enlarged lymph nodes in your neck area since these could be signs of cancer spread.

The doctor will also examine you for numbness or muscle weakness in part of your face (which can happen when cancer spreads into nerves) and any other related problem that you may be having.

If the results of this exam are abnormal, your doctor may order imaging tests or refer you to an otolaryngologist (a doctor specializing in ear, nose, and throat problems).

Imaging tests

Imaging tests use x-rays, magnetic fields, sound waves, or radioactive particles to create pictures of the inside of your body. Imaging tests may be done for a number of reasons, including to help find a suspicious area that might be cancerous, to learn how far cancer may have spread, and to help find out if treatment has been effective.

X-rays

If you have a mass near the jaw, your doctor may order x-rays of the jaws and teeth to look for a tumor.

If you have been diagnosed with cancer, an x-ray of your chest may be done to see if the cancer has spread to your lungs. It also provides other information about your heart and lungs that might be useful if surgery is planned.

Computed tomography (CT or CAT) scan

A CT scan is an x-ray procedure that produces detailed cross-sectional images of your body. Instead of taking one x-ray, a CT scanner takes many pictures as it rotates around you. A computer then combines these into images of slices of the part of your body that is being studied. CT scans provide better detail about soft tissues than standard x-rays and can often detect tumors.

Before any pictures are taken, you may be asked to drink 1 to 2 pints of a liquid called oral contrast. This helps outline the intestine so that certain areas are not mistaken for tumors. This is most often needed for CT scans of the abdomen or pelvis. You may also receive an IV (intravenous) line through which a different kind of contrast dye (IV contrast) is injected. This helps better outline structures in your body.

The injection can cause some flushing (redness and warm feeling). Some people are allergic and get hives or, rarely, more serious reactions like trouble breathing and low blood pressure. Be sure to tell the doctor if you have ever had a reaction to any contrast material used for x-rays.

You need to lie still on a table while the scan is being done. During the test, the table moves in and out of the scanner, a ring-shaped machine that completely surrounds the table. You might feel a bit confined by the ring you have to lie in while the pictures are being taken.

The CT scan can provide information about the size, shape, and position of a tumor and can help find enlarged lymph nodes that might contain cancer. If needed, CT scans can also be used to look for tumors in other parts of the body.

Magnetic resonance imaging (MRI)

Like CT scans, MRI scans provide detailed images of soft tissues in the body. But MRI scans use radio waves and strong magnets instead of x-rays. The energy from the radio waves is absorbed and then released in a pattern formed by the type of body tissue and by certain diseases. A computer translates the pattern into very detailed images of parts of the body. A contrast material called gadolinium is often injected into a vein before the scan to better see details.

MRI scans provide detailed images of soft tissues, so they can be helpful in determining the exact location and extent of a tumor. Sometimes they can help a doctor tell a benign tumor from a malignant one.

MRI scans may be a little more uncomfortable than CT scans. They take longer -- often up to an hour. You may be placed inside a large cylindrical tube, which is confining and can upset people with a fear of enclosed spaces. Special open MRI machines can help with this if needed. The MRI machine makes buzzing and clicking noises that you may find disturbing. Some places will provide earplugs or headphones to help block this out.

Positron emission tomography (PET) scan

PET scans involve injecting glucose (a form of sugar) that contains a radioactive atom into the blood. The amount of radioactivity used is very low. Cancer cells in the body are growing rapidly, so they absorb large amounts of the radioactive sugar. A special camera can then be used to create a picture of areas of radioactivity in the body. The picture is not finely detailed like a CT or MRI scan, but it can provide helpful information about your whole body.

A PET scan can help give the doctor a better idea of whether an abnormal lump or a mass seen on another imaging test may be cancer. If you have been diagnosed with cancer, your doctor may use this test to see if the cancer has spread to lymph nodes. A PET scan can also be useful if your doctor thinks the cancer may have spread but doesn't know where.

Some machines are able to perform both a PET and CT scan at the same time (PET/CT scan). This allows the doctor to compare areas of higher radioactivity on the PET scan with the more detailed appearance of that area on the CT.

Biopsy

Symptoms and the results of exams or imaging tests may strongly suggest that salivary gland cancer is present, but the actual diagnosis is made by removing cells from an abnormal area and looking at them under a microscope. This is known as a biopsy. Different types of biopsies may be done, depending on the situation.

Fine needle aspiration (FNA) biopsy

This type of biopsy can be done in a doctor's office or clinic. It is done with a hollow needle similar to those used for routine blood tests. Your doctor may first numb the area over the tumor with local anesthesia. The doctor then places the needle directly into the tumor mass for about 10 seconds and pulls cells and a few drops of fluid into a syringe. The cells are then viewed under a microscope by a specialist in diagnosing cancer (pathologist) to find out if they are malignant (cancerous).

Doctors may use FNA if they are not sure whether a mass is a salivary gland cancer. If the FNA shows the mass is due to an infection or is a kind of cancer that can be treated without surgery, then an unnecessary operation can sometimes be avoided.

An FNA biopsy is only helpful if enough representative cells are removed to be able to tell for certain what a mass is made of. But sometimes a biopsy is read as negative even when cancer is present. This most often occurs when the area biopsied is inflamed and full of immune system cells or when too few cells are removed to make a diagnosis.

Incisional biopsy

This type of biopsy may sometimes be done if the FNA does not get enough material to examine. In this procedure, the surgeon numbs the area over the tumor, makes a small incision and removes a tiny part of the tumor. The specimen is sent to the lab to be looked at by the pathologist. These types of biopsies are not done often for salivary gland tumors.

Surgery

As mentioned above, FNA biopsy of salivary gland cancers may not always provide an answer. If this is the case but the physical exam and imaging tests suggest that cancer may be present, the doctor may advise surgery to completely remove the mass. This can both provide enough of a sample for a diagnosis and treat the tumor at the same time. See the “Surgery for salivary gland cancer” section for more information.

In some cases if the exams and tests suggest cancer is likely, the doctor may skip the FNA biopsy altogether and go directly to surgically removing the tumor. The specimen is then sent to the lab to confirm the diagnosis.