Neuroendocrine Tumor of the Pancreas: Diagnosis

Approved by the Cancer.Net Editorial Board, 06/2019




This section describes options for diagnosing a pancreas NET. Not all tests listed below will be used for every person. Your doctor may consider these factors when choosing a diagnostic test:

  • The type of tumor suspected

  • Your signs and symptoms

  • Your age and general health

  • The results of earlier medical tests

Most pancreas NETs are found unexpectedly when people have x-rays or medical procedures done for reasons unrelated to the tumor. If a doctor suspects this type of tumor, he or she will ask for a complete medical and family history and perform a thorough physical examination. In addition, the following tests may be used to diagnose a pancreas NET:

  • Blood/urine tests. The doctor may take samples of blood and urine to check for abnormal levels of hormones, glucose, and other substances.

  • Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope and is required to make a diagnosis of NET. A pathologist then analyzes the sample(s) removed during the biopsy. A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease.

  • Molecular testing of the tumor. Your doctor may recommend running laboratory tests on a tumor sample to identify specific genes, proteins, and other factors unique to the tumor. Results of these tests can help determine your treatment options. This testing is less helpful in NETs than in other cancers.

  • 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. Additionally, a CT scan is used to see if a tumor has spread to the liver. 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.

  • Ultrasound. An ultrasound uses sound waves to create a picture of the internal organs. Tumors generate different echoes of the sound waves than normal. This means that when the waves are bounced back to a computer, creating images, the doctor can locate a mass inside the body. In some cases, a biopsy may be done during the procedure.

    There are different types of ultrasounds. During a standard transabdominal ultrasound, the probe is placed on the outside of the abdomen. However, these images are often not clear enough to diagnose small changes in the pancreas and other organs.

    During an endoscopic ultrasound, the probe is connected to the end of a thin, flexible, lighted tube called an endoscope. This tube is carefully slid down the esophagus into the stomach and duodenum, the top part of the small intestine. This type of ultrasound gives a clearer picture of the pancreas and other organs. Learn more about endoscopic techniques.

  • X-ray. An x-ray is a way to create a picture of the structures inside of the body, using a small amount of radiation. Sometimes, a pancreas NET may not show up on an x-ray because of its size or location, so the doctor may also recommend other types of scans. In some cases, the patient will be asked to swallow barium, which coats the mouth and throat, to provide better detail on the x-ray. This is called a barium swallow.

  • 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. Pancreas NETs are sometimes best shown using an MRI, especially if they have spread to the liver.

  • Nuclear medicine imaging. During this test, a small amount of a radioactive drug, called a tracer, is injected into a patient’s vein. The body is then scanned to show where the radioactivity has built up in the body. There are a few available methods of nuclear medicine imaging in NETs, including OctreoScan and 2 types of PET-CT scans.

    • OctreoScan. This imaging test uses octreotide linked with indium-111 as the tracer. This procedure is useful for identifying where a NET has spread, especially if it has spread to the liver. OctreoScan is slowly being replaced by the newer and more sensitive gallium-68 DOTATATE PET scan (see below).

    • Positron emission tomography (PET) or PET-CT scan. A PET scan is usually combined with a CT scan (see above), called a PET or PET-CT scan. The 2 types of tracers used in a PET scan include gallium-68 (68Ga) DOTATATE and (18F) fluorodeoxyglucose (FDG). The 68Ga DOTATATE PET is the primary scan used to look at slow-growing NETs (grades 1 and 2, see Stages and Grades). An FDG PET scan is sometimes used for faster-growing NETs (grade 3).

After diagnostic tests are done, your doctor will review all of the results with you. If the diagnosis is a pancreas NET, these results also help the doctor describe the tumor. This is called staging and grading.
