Malignant Pancreatic Vipoma

**Semantic type:** Neoplastic Process

**Definition:** A pancreatic neuroendocrine tumor producing vasoactive intestinal peptide (VIP). It is associated with watery diarrhea, hypokalemia, and hypochlorhydria or achlorhydria. It displays vascular invasion and metastasizes to other anatomic sites. One third of cases are metastatic at the time of diagnosis.