carcinoid /kär″sinoid/ [Gk, karkinos + eidos, form] , a small yellow tumor derived from argentaffin cells in the GI mucosa that secrete serotonin and other catecholamines. Carcinoid tumors spread slowly locally but may metastasize widely. Also called argentaffinoma, Kulchitsky cell carcinoma. See also argentaffin cell, carcinoid syndrome.
