Carcinoid syndrome is a group of symptoms associated with carcinoid tumors. These are tumors of the small intestine, colon, appendix, and bronchial tubes in the lungs.
Flush syndrome; Argentaffinoma syndrome
Carcinoid syndrome is the pattern of symptoms sometimes seen in people with carcinoid tumors. These tumors are rare, and often slow growing. Most carcinoid tumors are found in the gastrointestinal tract and lungs.
Carcinoid syndrome occurs in very few people with carcinoid tumors, after the tumor has spread to the liver or lung.
These tumors release too much of the hormone serotonin, as well as several other chemicals. The hormones cause the blood vessels to open (dilate). This causes carcinoid syndrome.
The carcinoid syndrome is made up of four main symptoms including:
Symptoms are sometimes brought on by physical exertion, or eating or drinking things such as blue cheese, chocolate, or red wine.
Surgery to remove the tumor is usually the first treatment. It can permanently cure the condition if the tumor is completely removed.
If the tumor has spread to the liver, treatment involves either of the following:
When the entire tumor can't be removed, removing large portions of the tumor ("debulking") can help relieve the symptoms.
Octreotide (Sandostatin) or lanreotide (Somatuline) injections are given to people with advanced carcinoid tumors that can't be removed with surgery.
People with carcinoid syndrome should avoid alcohol, large meals, and foods high in tyramine (aged cheeses, avocado, many processed foods), because they may trigger symptoms.
Some common medicines, like selective serotonin reuptake inhibitors (SSRIs), such as paroxetine (Paxil) and fluoxetine (Prozac), may make symptoms worse by increasing levels of serotonin. However, DO NOT stop taking these medicines unless your provider tells you to do so.
Learn more about carcinoid syndrome and get support from:
The outlook in people with carcinoid syndrome is sometimes different from the outlook in people who have carcinoid tumors without the syndrome.
Prognosis also depends on the site of tumor. In people with the syndrome, the tumor has usually spread to the liver. This lowers the survival rate. People with carcinoid syndrome are also more likely to have a separate cancer (second primary tumor) at the same time. Overall, the prognosis is usually excellent.
Complications of carcinoid syndrome may include:
A fatal form of carcinoid syndrome, carcinoid crisis, may occur as a side effect of surgery, anesthesia or chemotherapy.
Contact your provider for an appointment if you have symptoms of carcinoid syndrome.
Treating the tumor reduces the risk of carcinoid syndrome.
National Cancer Institute website. Gastrointestinal carcinoid tumors treatment (Adult) (PDQ) - health professional version. www.cancer.gov/types/gi-carcinoid-tumors/hp/gi-carcinoid-treatment-pdq. Updated September 16, 2020. Accessed October 14, 2020.
Öberg K. Neuroendocrine tumors and related disorders. In: Melmed S, Auchus, RJ, Goldfine AB, Koenig RJ, Rosen CJ , eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 45.
Wolin EM, Jensen RT. Neuroendocrine tumors. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 219.