Adenoid Cystic Carcinoma: Diagnosis

Approved by the Cancer.Net Editorial Board, 12/2021

ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors use to find the cause of the 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 adenoid cystic carcinoma is treated

There are many tests used for diagnosing adenoid cystic carcinoma (AdCC). 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

In addition to a physical examination, the following tests may be used to diagnose AdCC:

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 pathology of the salivary gland may be complicated, even among experienced pathologists. This is why it is important that the tissue is examined by a head and neck pathologist who is experienced in diagnosing salivary gland diseases.

The biopsy can be performed in different ways: using a fine needle biopsy or by surgically removing part or all of the tumor. A fine needle biopsy is also called fine needle aspiration or FNA. This procedure uses a thin needle to remove fluid and cells from the suspicious area. An AdCC tumor is characterized by a distinctive pattern in which bundles of epithelial cells surround and/or infiltrate ducts or glandular structures within the organ. Frequently, diagnosis of AdCC is made after the surgical removal of a tumor first thought to be benign.

Imaging tests. Imaging techniques, primarily magnetic resonance imaging (MRI) or computed tomography (CT) scan, are useful to help doctors see the size and location of the tumor before surgery. A positron emission tomography (PET) scan may also be used to determine if the tumor has spread to other parts of the body. Each scan is described in more detail below.

  • Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. 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 patient’s vein or given as a pill or liquid to swallow. An MRI is very useful for identifying perineural spread of AdCC. Perineural spread is growth of the tumor along nerve branches.

  • 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.

  • 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 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. However, the amount of radiation in the substance is too low to be harmful. 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.

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. 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.