Carcinoid Syndrome

Abstract

Carcinoid syndrome occurs in approximately 20% of patients with neuroendocrine tumours. Its pathophysiology is not completely understood; however, it is thought to arise from secretion of serotonin and kinins from the neuroendocrine tumour cells. In patients with liver metastases these hormones are not metabolized by the liver and consequently lead to the symptoms of carcinoid syndrome. The most common symptoms are diarrhoea, flushing, abdominal pain, and wheezing. Management of carcinoid syndrome is centred around control of tumour growth and symptoms. First line treatment is with somatostatin analogues, more recently Telotristat ethyl has been licensed for refractory syndrome. A number of complications can arise secondary to serotonin and kinin secretion these include nutritional deficiency, mesenteric fibrosis, and carcinoid heart disease. Carcinoid crisis which comprises of severe haemodynamic instability can occur during times of stress or surgery. Careful preoperative management needs to be considered prior to surgery in this cohort of patients.