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What is Carcinoid syndrome is associated with all except? and explain in detail?
Vanillyl Mandelic acid (V.M.A) is an end product of catecholamine metabolism and is used for screening for pheochromocytoma. In carcinoid syndrome, the 5HT derivative histamine results in flushing episodes. Neuroendocrine tumors along the GI tract use tryptophan as the source for serotonin production, which limits the available tryptophan for niacin synthesis. In normal patients, only one percent of dietary tryptophan is conveed to serotonin; however, in patients with carcinoid syndrome, this value may increase to 70%. Carcinoid syndrome may thus produce Niacin deficiency and clinical manifestations of pellagra. 5HT derivative histamine released by carcinoid causes bronchospasm and rhonchi.