Tests and diagnosis

By Mayo Clinic Staff

Tests and procedures used to diagnose carcinoid tumors include:

  • Blood tests. If you have a carcinoid tumor, your blood may contain high levels of hormones secreted by a carcinoid tumor or byproducts created when those hormones are broken down by the body.
  • Urine tests. People with carcinoid tumors have excess levels of a chemical in their urine that's produced when the body breaks down hormones secreted by carcinoid tumors.
  • Imaging tests. Imaging tests, including a computerized tomography (CT) scan, magnetic resonance imaging (MRI), positron emission tomography (PET), octreotide scan and X-ray, may help your doctor pinpoint the carcinoid tumor's location.
  • A scope or camera that sees inside your body. Your doctor may use a long, thin tube equipped with a lens or camera to examine areas inside your body.

    An endoscopy, which involves passing a scope down your throat, may help your doctor see inside your gastrointestinal tract. Bronchoscopy, using a scope passed down your throat and into your lungs, can help find lung carcinoid tumors. Passing a scope through your rectum (colonoscopy) can help diagnose rectal carcinoid tumors.

    To see inside your small intestine, your doctor may recommend a test using a pill-sized camera that you swallow (capsule endoscopy).

  • Removing tissue for laboratory testing. A sample of tissue from the tumor (biopsy) may be collected to confirm your diagnosis. What type of biopsy you'll undergo depends on where your tumor is located.

    In some cases a surgeon may use a needle to draw cells out of the tumor. In other cases, a biopsy may be collected during surgery. The tissue is sent to a laboratory for testing to determine the types of cells in the tumor and how aggressive those cells appear under the microscope.

Dec. 20, 2012