Carcinoid syndrome

Carcinoid syndrome is a paraneoplastic syndrome made up of the signs and symptoms that occur secondary to neuroendocrine tumors, which were formerly called carcinoid tumors. The syndrome arises when such tumors, most often found in the gut, release biologically active substances into the blood. The usual symptoms are flushing and diarrhea, and less frequently heart failure, vomiting and bronchoconstriction. Because it results from substances released by a tumor rather than from the tumor mass itself, it is classed as a syndrome accompanying neoplasm. The Wikipedia lead is brief, so this entry records only what that lead supports, leaving diagnosis and treatment to later research.