amine precursor uptake & decarboxylation tumor (APUDoma)

Etiology

• pancreatic islet cell (alpha-cell) carcinoma
• may be derived from other neuroendocrine sites

Epidemiology

rare

Pathology

• secretion of gastrointestinal hormones
  • vasoactive intestinal polypeptide (VIP)
    • secretory diarrhea
    • hypokalemia
    • flushing
  • glucagon
    • diabetes mellitus
    • skin rash, especially migrating necrotizing erythema
  • somatostatin
    • gallstones
    • diabetes mellitus
    • steatorrhea
  • gastrin
    • esophagitis
    • peptic ulcer
  • pancreatic polypeptide (P-Poma)
    • no characteristic clinical syndrome
• secretion of other endocrine peptides
  • GRFoma
  • CRFoma
  • neurotensinoma
  • parathyroidoma
  • vasopressinoma
  • MSHoma
• 80% of tumors are multiple or malignant

Laboratory

• serum chemistries
  • gastrin
  • vasoactive intestinal polypeptide (VIP)
  • glucagon
  • somatostatin
  • pancreatic polypeptide
  • chromogranin A may serve as a marker for all APUDomas

Radiology

• computed tomography (CT) & spiral CT
• octreotide radioisotope scan
  • most APUDomas express cell surface somatostatin receptors
• endoscopic ultrasonography
• gadolinium-enhanced magnetic resonance imaging (MRI)
• angiography

Management

• prognosis is better than for adenocarcinoma of the pancreas
• surgical resection for single & benign tumors
• high dose proton pump inhibitor for gastrinoma
  • omeprazole 40-240 mg/day
• surgical debulking of tumor
  • VIPoma
  • glucagonoma
  • somatostatinoma
  • P-Poma
• octreotide injections 50-300 ug SQ QD can control hormonal effects & lead to tumor regression in some patients

More general terms

• neuroendocrine neoplasm

More specific terms

• CRFoma
• glucagonoma
• GRFoma; GRHoma
• neurotensinoma
• pancreatic polypeptideoma (PPoma)
• somatostatinoma
• vasoactive intestinal polypeptide-secreting tumor (VIPoma)
• Zollinger-Ellison (ZE) syndrome (gastrinoma)