Tests and diagnosis

By Mayo Clinic Staff

Your doctor will assess your signs and symptoms in order to rule out other causes of skin flushing and diarrhea. If no other causes are found, your doctor may suspect carcinoid syndrome. To confirm a diagnosis, your doctor may recommend further tests, including:

  • Urine test. Your urine may contain a substance made when your body breaks down serotonin. An excess amount of this substance could indicate that your body is processing extra serotonin, the chemical most commonly excreted by carcinoid tumors.
  • Blood test. Your blood may contain high levels of certain substances, including the protein chromogranin A, which is released by some carcinoid tumors.
  • Imaging tests. Imaging tests also may be used to locate the primary carcinoid tumor and determine whether it has spread. Your doctor may start with a computerized tomography (CT) scan of your abdomen, because most carcinoid tumors are found in the gastrointestinal tract.
Jul. 10, 2012