ON THIS PAGE: You will find a list of the common tests, procedures, and scans that doctors can use to find out what’s wrong and identify the cause of the problem. To see other pages in this guide, use the colored boxes on the right side of your screen, or click “Next” at the bottom.
Doctors use many tests to diagnose a tumor and find out if it has metastasized (spread). Some tests may also determine which treatments may be the most effective. For most types of tumors, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has spread. This list describes options for diagnosing this type of cancer, and not all tests listed will be used for every person. Your doctor may consider these factors when choosing a diagnostic test:
- Age and medical condition
- Type of cancer suspected
- Signs and symptoms
- Previous test results
Most carcinoid tumors are found unexpectedly when people have x-rays or medical procedures done for reasons unrelated to the tumor. For example, many carcinoid tumors of the appendix are found during an appendectomy (surgery to remove the appendix), while duodenal (the top of the small intestine) and stomach carcinoid tumors are usually found during an endoscopy (see below).
If a doctor suspects a carcinoid 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 carcinoid tumor:
Blood/urine tests. The doctor may need samples of the patient’s blood and urine to check for abnormal levels of hormones and other substances. Urine tests check the measurement of 5-HIAA (see Overview ). Measurements for serotonin levels may also be taken. A doctor may be able to diagnose a carcinoid tumor from a urine test alone. A blood test to measure chromogranin-A may be needed since the serum serotonin level often changes and may not be as useful as a chromogranin-A test.
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. The sample removed during the biopsy is examined by a pathologist (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 will help decide whether your treatment options include a type of treatment called targeted therapy (see Treatment ).
Endoscopy . This test allows the doctor to see the lining of the upper digestive system with a thin, lighted, flexible tube called an endoscope. The person may be sedated as the tube is inserted through the mouth, down the esophagus, and into the stomach and small bowel. If an abnormality is found, a biopsy will be performed.
A colonoscope  is a type of endoscope that is inserted through the anus and into the colon. It can be used to diagnose a tumor in the lower section of the digestive system.
Endoscopic ultrasound . An ultrasound uses sound waves to create a picture of the internal organs. This procedure is often done at the same time as an upper endoscopy. In an endoscopic ultrasound, a transducer (a machine that produces the sound waves) is inserted into the upper digestive tract through the mouth. The endoscopic ultrasound can show enlarged lymph nodes, which may help indicate a tumor or the stage of the disease.
Bone scan . A bone scan uses a radioactive tracer to look at the inside the bones. The tracer is injected into a patient’s vein. It collects in areas of the bone and is detected by a special camera. Healthy bone appears gray to the camera, and areas of injury, such as those caused by cancer, appear dark.
X-ray. An x-ray is a way to create a picture of the structures inside the body. For instance, a chest x-ray may be taken to look for a carcinoid tumor in the lungs. Sometimes, a carcinoid tumor may not show up on a chest x-ray because of its size or location so the doctor may also recommend other types of scans.
Barium x-rays. In a barium swallow, a person swallows a liquid containing barium, and then a series of x-rays are taken. The barium coats the lining of the esophagus, stomach, and intestines so abnormalities are easier to see on the x-ray. If there is an abnormality, an endoscopic biopsy can help make the diagnosis of cancer.
A barium enema  may be given before x-rays are taken to show the inner surface of the large intestine. During this test, a barium solution is given through the anus and flows throughout the colon, and then the x-rays are taken.
Computed tomography (CT) scan . A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. A CT scan can also be used to measure the tumor’s size. Additionally, a CT scan is used to see if the tumor has spread to the liver and to detect a carcinoid tumor in the retroperitoneal (the area behind the abdomen) lymph nodes. Sometimes, a contrast medium (a special dye) is injected into a patient’s vein or given orally (by mouth) to provide better detail.
Magnetic resonance imaging (MRI) . An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. A contrast medium may be injected into a patient’s vein or given orally (by mouth) to create a clearer picture. MRI often produces clearer images of carcinoid tumor than CT scanning.
Radionuclide scanning (OctreoScan). A small amount of a radioactive hormone-like substance that is attracted to carcinoid tumors is injected into a patient’s vein. A special camera is then used to show where the radioactivity has built up in the body. This procedure is useful for identifying where a carcinoid tumor has spread, especially if it has spread to the liver.
Positron emission tomography (PET) scan . A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive substance is injected into a patient’s body. This substance is absorbed mainly by organs and tissues that use the most energy. Because a tumor 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. However, because a carcinoid tumor grows very slowly, a PET scan may not be as helpful as other tests for diagnosis.
After these diagnostic tests are done, your doctor will review all of the results with you. If the diagnosis is cancer, these results also help the doctor describe the cancer; this is called staging.
Choose “Next” (below, right) to continue reading this guide to learn about the different stages for this type of cancer. Or, use the colored boxes located on the right side of your screen to visit any section.