A Spotlight on NET Syndromes – Carcinoid Syndrome
What is Carcinoid Syndrome? Carcinoid syndrome (CS) is the most frequent hormonal complication accompanying neuroendocrine neoplasms (NENs) and is defined by chronic diarrhoea and/or flushing in the presence of systemic elevated levels of serotonin or its metabolite 5-hydroxyindolacetic acid (5-HIAA). Importantly, other causes of these symptoms should be considered and investigated depending on the clinical presentation. CS is predominantly encountered in patients with well-differentiated NENs (neuroendocrine tumours, NETs) of intestinal origin, followed by lung NETs, and only in a minority of patients with pancreatic, ovarian, thymic, or unknown origin NETs. The main symptoms defining CS are skin flushing, secretory diarrhoea, bronchospasm, or…
