Most pancreatic cancers, including nonfunctional pancreatic neuroendocrine tumors (NETs), do not cause symptoms until they become large or spread to other parts of the body. For example, if cancer spreads to the liver, it may cause liver enlargement, abdominal pain, poor appetite, and jaundice. If it spreads to the lungs, it may cause breathing problems or coughing. Conditions other than cancer may cause these signs and symptoms. If you have any of these, see your doctor to find out the reason.
Some pancreatic NETs produce and release hormones. These are called functional NETs, and they may cause symptoms, based on which hormone they release, including:
- Insulinomas: low blood sugar and related symptoms (like weakness and confusion); fast heartbeat; if blood sugar gets very low, unconsciousness, coma, and seizures
- Glucagonomas: high blood sugar, diabetes, diarrhea, weight loss, nutrition problems, and skin rash on the face, stomach, or legs
- Gastrinomas: recurring stomach ulcers, diarrhea, weight loss, and gastroesophageal reflux
- Somatostatinomas: diarrhea, diabetes, abdominal pain, nausea, poor appetite, and jaundice
- Vasoactive intestinal peptide tomors (VIPomas): diarrhea, digestion problems, high blood sugar, and low potassium (which may cause weakness, cramps, numbness, tingling, and other symptoms)
- Pancreatic polypeptidomas (PPomas): abdominal pain, enlarged liver, and diarrhea
If you have signs or symptoms that could be from pancreatic NETs, your doctor will start by asking about your medical history and family history and doing a physical exam. You may also need one or more of these procedures.
- Computed tomography scan (CT scan). This imaging test uses X-rays to generate cross-sectional pictures of the body. These pictures can help a doctor see if there is an abnormal growth in the pancreas.
- Magnetic resonance imaging (MRI). An MRI uses radio waves to create detailed pictures of the body. Like CT scans, MRIs can help a doctor detect abnormal growths.
- Somatostatin receptor scintigraphy (OctreoScan). For this test, a doctor injects into the blood a hormone-like substance that is bound to a radioactive substance. This travels through the body and attaches to proteins on the tumor cells of many NETs. A scan shows where the radioactivity has collected, which helps the doctor identify tumors.
- Endoscopic ultrasound. Ultrasound uses sound waves to create a picture of an organ, like the pancreas, or other internal structure. It can be done by placing an ultrasound probe against the skin of the abdomen from the outside, or it can be done by attaching the ultrasound probe to an endoscope—a thin, flexible tube that is threaded down the throat, through the stomach, and into the small intestine (endoscopic ultrasound).
- Endoscopic retrograde cholangiopancreatography (ERCP). This is another way of getting information about the pancreas from the inside. An endoscope is passed through the mouth down into the small intestine. The tube has a camera so the doctor can see these structures. The doctor injects dye into the tube, so the area shows more clearly on an X-ray. During an ERCP, the doctor may also put a small brush into the pancreas (through the endoscope) in order to take out cells for a biopsy (to look at the cells under a microscope and see if they are cancer).
- Angiography. To detect blood vessels that serve a possible tumor or may be compressed by a tumor, a doctor may inject a dye into a nearby artery and then take X-rays, where the dye shows up. This is angiography. It may be helpful for finding small NETs.
Samples of blood can be checked to measure the level of hormones, which may be abnormal with some NETs, and to check for a substance called chromogranin-A (CgA), which goes up with most pancreatic NETs.
A biopsy is the only way to definitively diagnose pancreatic NETs. So if your symptoms and any scans or tests lead your doctor to suspect you have pancreatic cancer, the doctor takes a sample of cells so a pathologist can examine the cells for cancer. Sometimes the sample is taken by inserting a thin needle through the abdomen into a suspected tumor to withdraw some cells (fine-needle aspiration).
A biopsy may also be done surgically. Often the surgeon makes small incisions in the abdomen (laparoscopy) and then inserts a thin, flexible scope and biopsy instruments. Sometimes the surgeon needs to make a larger incision in the abdomen (laparotomy). The surgeon may do a fine-needle aspiration or use a larger needle to take a bigger sample of cells (core needle biopsy). During a surgical biopsy procedure, the surgeon can also view the pancreas and surrounding organs. This can help your team determine the next step in your care.