Factors responsible for the carcinoid spectrum. A review

Current knowledge strongly supports the theory that the carcinoid spectrum reflects the clinical signs of production, by a carcinoid tumor or by metastatic lesions, of one or more humoral substances. Serotonin, the kinins, histamine (and perhaps other amines), adrenocorticotropic hormone and additional hormones are manufactured by these tumors. Elevated concentrations of serotonin, the kinins and histamine have been found in patients with the carcinoid syndrome, which includes right-sided valvular heart disease, peripheral vasomotor disturbances, bronchoconstriction, borborygmi and an unusual type of cyanosis.