Diagnosis of salivary gland cancer

Diagnosis is the process of finding out the cause of a health problem. Diagnosing salivary gland cancer usually begins with a visit to your family doctor. Your doctor will ask you about any symptoms you have and do a physical exam. Based on this information, your doctor may refer you to a specialist or order tests to check for salivary gland cancer or other health problems.

The process of diagnosis may seem long and frustrating. It's normal to worry, but try to remember that other health conditions can cause similar symptoms as salivary gland cancer. It's important for the healthcare team to rule out other reasons for a health problem before making a diagnosis of salivary gland cancer.

The following tests are usually used to rule out or diagnose salivary gland cancer. Many of the same tests used to diagnose cancer are used to find out the stage (how far the cancer has progressed). Your doctor may also order other tests to check your general health and to help plan your treatment.

Your health history is a record of your symptoms, risk factors and all the medical events and problems you have had in the past. Your doctor will ask questions about your history of:

• symptoms that suggest salivary gland cancer
• exposure to radiation

Your doctor may also ask about a family history of any type of head and neck cancer.

A physical exam allows your doctor to look for any signs of salivary gland cancer. During a physical exam, your doctor may:

• check for any lumps in your jaw, cheek, neck and mouth
• look for any changes to your face, such as drooping muscles, unevenness or twitching
• test for areas of numbness, or lack of feeling, on your face
• ask you to open your mouth and move your tongue
• use a small mirror and a light to look inside your mouth

Find out more about physical exams.

An x-ray uses small doses of radiation to make an image of parts of the body on film. Your doctor may order an x-ray to look at an area of swelling or a lump on your jaw.

Find out more about x–rays.

A computed tomography (CT) scan uses special x-ray equipment to make 3D and cross-sectional images of organs, tissues, bones and blood vessels inside the body. A computer turns the images into detailed pictures.

A CT scan is used to find a salivary gland tumour and get more information about its size, shape and location. It is also used to find out if the tumour has grown into tissues around the salivary gland, nerves in the face or nearby lymph nodes.

Doctors may also use CT scan to guide them to a tumour during a biopsy. CT scan of the chest is used to look for cancer that has spread to the lungs.

Find out more about CT scans.

Magnetic resonance imaging (MRI) uses powerful magnetic forces and radiofrequency waves to make cross-sectional images of organs, tissues, bones and blood vessels. A computer turns the images into 3D pictures.

An MRI is becoming more common as a diagnostic test for tumours in a parotid gland. It is used to find a tumour and get more information about its size, shape and location. MRI is also used to find out if the tumour has grown into tissues around the salivary gland, nerves in the face or nearby lymph nodes. MRI is better than a CT scan for telling if a salivary gland tumour is non-cancerous or cancerous.

Find out more about MRIs.

An ultrasound uses high-frequency sound waves to make images of parts of the body. An ultrasound may help identify the type of salivary gland tumour. It may also give the doctors information about the blood supply to the tumour and to guide a biopsy.

Find out more about ultrasounds.

During a biopsy, the doctor removes tissues or cells from the body so they can be tested in a lab. A report from the pathologist will show whether or not cancer cells are found in the sample.

Fine needle aspiration (FNA) uses a very thin needle and syringe to remove a small amount of fluid or cells from a lump or a mass.

Incisional biopsy removes a small piece of tissue from a lump in a salivary gland through a surgical incision, or cut. It may be done if the doctor can't get enough tissue from FNA to make a diagnosis.

If the imaging tests and biopsy don't help doctors make a diagnosis, the whole lump may be removed during surgery, and then tested for cancer cells.

Find out more about biopsies.

Cells and tissues are analyzed in the lab to look for cancer. A report from a pathologist will show whether or not cancer cells are found in the sample, and what type of cancer has been found.

Molecular genetic studies look for certain changes (mutations) in the genes of salivary gland cells. These changes affect the type of treatment given. Specific targeted therapy drugs are used for specific gene mutations. Molecular tests for salivary gland cancer look for the following gene change.

NTRK gene fusions are caused when a piece of the neurotrophic tyrosine receptor kinase (NTRK) gene breaks off and joins with another gene. This change causes abnormal proteins called TRK fusion proteins, which may cause cancer cells to grow.

Find out more about cell and tissue studies and genetic changes and cancer risk.

To make the decisions that are right for you, ask your healthcare team questions about a diagnosis.