Diagnosis

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), X-ray and nuclear medicine scans, 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. A 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.

  One way of collecting a tissue sample involves using a needle to draw cells out of the tumor. Another option may be through 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.