Serotonin-Secreting Neuroendocrine Tumours of the Pancreas.

Primary 5-HT-secreting pNETs are mostly metastatic to the liver; patients are not amenable to resective surgery. Despite high 5-HIAA urinary levels, few patients present with carcinoid syndrome. A five-year survival rate of 42.9% may be achieved with multimodal treatment.