Tests and diagnosis
By Mayo Clinic staffYour 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.
References
- A review of carcinoid cancer. Carcinoid Cancer Foundation. http://www.carcinoid.org/pcf/docs/review.html#SYN. Accessed April 10, 2010.
- How are gastrointestinal carcinoid tumors diagnosed? American Cancer Society. http://www.cancer.org/docroot/CRI/content/CRI_2_4_3X_How_is_gastrointestinal_carcinoid_tumors_diagnosed_14.asp?sitearea=. Accessed April 10, 2010.
- Carcinoid tumor. American Society of Clinical Oncology. http://www.cancer.net/patient/Cancer+Types/Carcinoid+Tumor?sectionTitle=Symptoms. Accessed April 10, 2010.
- Sitaraman SV, et al. Clinical features of the carcinoid syndrome. http://www.uptodate.com/home/index.html. Accessed April 12, 2010.
- Sitaraman SV, et al. Treatment of carcinoid tumors and the carcinoid syndrome. http://www.uptodate.com/home/index.html. Accessed April 12, 2010.
- Connolly HM. Carcinoid heart disease. http://www.uptodate.com/home/index.html. Accessed April 12, 2010.
- Ghevariya V, et al. Carcinoid tumors of the intestinal tract. Southern Medical Journal. 2009;102:1032.
- Bhattacharyya S, et al. Carcinoid heart disease. Circulation. 2007;116:2860.
- Moynihan TJ (expert opinion). Mayo Clinic, Rochester, Minn. April 19, 2010.

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