Carcinoid syndrome

Definition:

A group of symptoms typically associated with carcinoid tumor (See also Bronchial adenoma).

Causes, incidence, and risk factors:

Carcinoid syndrome is the pattern of symptoms that typically are exhibited by people with carcinoid tumors. Carcinoid tumors are tumors that secrete excessive amounts of the hormone serotonin. Serotonin causes the blood vessels to widen (dilate). It also causes increased blood clotting because it stimulates platelets to aggregate (clump together). Serotonin is converted by the body to 5-HIAA. The precursor to serotonin is tryptophan, an amino acid that is also used by the body to manufacture niacin and certain proteins.

The most pronounced and bothersome symptoms include: bright red facial flushing, diarrhea (which may be explosively severe), and occasionally wheezing.

In children, carcinoid usually occurs in the appendix and removal of the appendix results in a complete cure.