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amine precursor uptake & decarboxylation tumor (APUDoma)
Etiology:
- pancreatic islet cell (alpha-cell) carcinoma
- may be derived from other neuroendocrine sites [3]
Epidemiology: rare
Pathology:
1) secretion of gastrointestinal hormones
a) vasoactive intestinal polypeptide (VIP)
1] secretory diarrhea
2] hypokalemia
3] flushing
b) glucagon
1] diabetes mellitus
2] skin rash, especially migrating necrotizing erythema
c) somatostatin
1] gallstones
2] diabetes mellitus
3] steatorrhea
d) gastrin
1] esophagitis
2] peptic ulcer
e) pancreatic polypeptide (P-Poma)
-> no characteristic clinical syndrome
2) secretion of other endocrine peptides
a) GRFoma
b) CRFoma
c) neurotensinoma
d) parathyroidoma
e) vasopressinoma
f) MSHoma
3) 80% of tumors are multiple or malignant
Laboratory:
-> serum chemistries
a) gastrin
b) vasoactive intestinal polypeptide (VIP)
c) glucagon
d) somatostatin
e) pancreatic polypeptide
f) chromogranin A may serve as a marker for all APUDomas
Radiology:
1) computed tomography (CT) & spiral CT
2) octreotide radioisotope scan
-> most APUDomas express cell surface somatostatin receptors
3) endoscopic ultrasonography
4) gadolinium-enhanced magnetic resonance imaging (MRI)
5) angiography
Management:
1) prognosis is better than for adenocarcinoma of the pancreas
2) surgical resection for single & benign tumors
3) high dose proton pump inhibitor for gastrinoma
- omeprazole 40-240 mg/day
4) surgical debulking of tumor
a) VIPoma
b) glucagonoma
c) somatostatinoma
e) P-Poma
4) octreotide injections 50-300 ug SQ QD can control hormonal effects & lead to tumor regression in some patients
Specific
CRFoma
glucagonoma
GRFoma; GRHoma
neurotensinoma
pancreatic polypeptideoma (PPoma)
somatostatinoma
vasoactive intestinal polypeptide-secreting tumor (VIPoma)
Zollinger-Ellison (ZE) syndrome (gastrinoma)
General
neuroendocrine neoplasm
References
- Medical Knowledge Self Assessment Program (MKSAP) 11, 15, 16.
American College of Physicians, Philadelphia 1998, 2009, 2012
- Harrison's Principles of Internal Medicine, 14th ed.
Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 585
- Philippe J.
APUDomas: acute complications and their medical management.
Baillieres Clin Endocrinol Metab. 1992 Jan;6(1):217-28.
PMID: 131084