Carcinoid syndrome and its sequelae

Abstract The carcinoid syndrome is a result of a combination of peptide and amines commonly secreted by advanced neuroendocrine tumours, usually of small bowel primary origin, with a large overall tumour burden. Characteristically, this syndrome is defined by presence of flushing, diarrhoea and wheezing, and serotonin is considered as the principle causative molecule. Carcinoid crisis carries a high mortality and is therefore considered a medical emergency. In addition, long-term sequelae of the carcinoid syndrome include multiple organ systems including the heart, gastrointestinal system, skin and neurological system. Management of carcinoid syndrome and its complications often requires a multi-faceted approach and should be carried out with simultaneous management of the neuroendocrine tumour. This review describes the pathophysiology, symptomatology, acute and chronic complications and management of the carcinoid syndrome.