Detlef Bartsch

1 INTRODUCTION Vasoactive intestinal peptide–secreting tumors (VIPomas) are exceptionally rare functioning pancreatic neuroendocrine tumors (PanNET), first described by Verner and Morrison in 1958.1 The annual incidence is estimated to be approximately 1 in 10 million people, accounting for about 1%–3% of all PanNET.2-4 VIPomas are characterized by excessive secretion of vasoactive intestinal peptide (VIP), resulting in the classical watery diarrhea–hypokalemia–achlorhydria (WDHA) syndrome.1...

1 INTRODUCTION Both incidence and prevalence of neuroendocrine tumours (NETs) have been rising steadily, particularly over the past two decades.1 While this increase is largely driven by the growing detection of small, incidental lesions, the number of metastatic cases is also increasing.2 Metastatic disease still accounts for the presentation of most NETs, and its management often poses a significant challenge for clinicians.

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