Presentation of the<unk> . The<unk>  occurs in approximately 5% of<unk>  tumors and becomes manifest when vasoactive substances from the tumors enter the systemic circulation escaping hepatic degradation. If the primary tumor is from the gastrointestinal tract (hence releasing serotonin into the hepatic portal circulation),<unk>  generally does not occur until the disease is so advanced that it overwhelms the liver's ability to metabolize the released serotonin. * Flushing: The most important clinical finding is flushing of the skin, usually of the head and the upper part of thorax. * Diarrhea: It may be associated with abdominal cramping. This symptom is due to the action of serotonin, histamine, and gastrin * Abdominal pain: It is due to hepatomegaly, small bowel obstruction or lack of oxygen to small bowel. * Bronchoconstriction, which may be histamine or serotonin-induced, affects about 15% of those having<unk>  and often accompanies flushing, sneezing, and shortness of breath. *<unk>  heart disease: About 19% to 60% of the those affected by<unk>  develop<unk>  heart disease. Serotonin induces fibrosis in valves of the right heart especially tricuspid valve.
Carcinoid syndrome
Anaphylaxis
Carcinosis
Stress ulcer
Portal hypertension
Madarosis
Amyloidosis
Alcohol intolerance