25th May 2025

Carcinoid Syndrome

Carcinoid syndrome is a paraneoplastic syndrome caused by the release of neuroendocrine hormones including serotonin. It is more common with midgut NETs and in those with liver metastases. It causes flushing, wheeze, pellagra, abdominal pain and palpitations. It can be diagnosed by 24 hour urinary 5-HIAA. Treatment is by managing the underlying tumour.