**Neuroendocrine Tumors** **Glucagonoma** * Pancreatic α cells → glucagon * Clinical features: * Insulin resistance * Secondary diabetes * Weight loss * Necrolytic migratory erythema → characteristic skin rash * Chronic diarrhea * OVT * Depression * Diagnostics: * ↑ glucagon > 500 pg/mL * ↑ BSL * Normocytic normochromic anemia * CT to localize tumor * Treatment & Management: * Glycemic control * Tumor resection * Somatostatin analog * Octreotide if tumor is inoperable **VIPoma** * MOST COMMON APUDoma not α or β cells * VIP secretion → associated with MEN1 Syndrome * Pathophysiology: * VIP → relaxation of gastric & intestinal SM → CAMP → secretory diarrhea * Vasodilation * ↓ water absorption * Similar to cholera toxin * ↓ gastric acid production * Clinical features: * WDHA syndrome * Watery diarrhea * Hypokalemia * Achlorhydria * tea-colored watery > 700ml/day → dehydration * diarrhea → weight loss → abdominal pain → nausea → vomiting → achlorhydria → ↓ iron & B₁₂ absorption → anemia * Diagnostics: * ↑ serum gastrin > 150 pg/ml * ↑ basal acid output * Hypergastrinemia or hyperchlorhydria * CT scan to localize 1° tumor * Treatment & Management: * Tumor resection * Octreotide → ↓ VIP secretion **Somatostatinoma** * rare neuroendocrine tumor of δ-cells/D cells - located @ pancreas or GIT * ↓ gastric acid and pepsin secretion * ↓ pancreatic exocrine secretions * ↓ bile secretion into duodenum * ↓ gallbladder contraction * ↓ pancreatic insulin secretion * ↓ gastric acid secretion * ↓ pancreatic exocrine secretion * Clinical features: * abdominal pain * weight loss * glucose intolerance/DM (due to ↓ insulin) * achlorhydria * steatorrhea (due to ↓ pancreatic exocrine) * cholelithiasis (due to ↓ gallbladder contraction) * induced protein secretion * Diagnostics = * ↑ somatostatin * ↑ BSL * Imaging to localize tumor * Treatment & Management = * Tumor resection * Curative * If no metastasis is present * Octreotide → ↓ GH * If tumor is inoperable * Chemotherapy