carcinoid tumors

Definition of carcinoid tumor
National Cancer Institute

carcinoid tumor

(KAR-sih-noyd TOO-mer)
A slow-growing type of tumor usually found in the gastrointestinal system (most often in the small intestine and rectum), and sometimes in the lungs or other sites. Carcinoid tumors may spread to the liver or other sites in the body, and they may secrete substances such as serotonin or prostaglandins, causing carcinoid syndrome.

Source: NCI Dictionary of Cancer Terms