Neuroendocrine Tumors


The role of "markers" in the diagnosis / differential diagnosis of GEP-NET
1. CHROMOGRANINs (CgA + CgB) in serum (primary vesicular - LDCV - large dense-core vesicles)

CgA positiv in plasma in 94% (70-100%) CgB : pos. immunhistochemistry in benign insulinomas
false positiv: renal failure, hepatic failure, atrophical gastritis, proton pump blocker therapy (gastrin), inflammatory bowel disease
cleavage products of CgA:: Pancreastatin: inhibits insulin, glucagon, PTH, parietal cells, exocrine pancreas
Vasostatin: suppresses vasoconstriction, PTH, stimulates cell adhesion
Parastatin: inhibits PTH
Chromostatin: inhibits catecholamines
2. Synaptophysin (vesicular - SSV - small synaptic-like vesicles)
Monoamine Transporters (vesiculär - VMAT-1, VMAT-2)
3. Pancreatic Polypeptide (PP) : positiv in up to 74% of GEP-NET
4. nuclear Ki67-expression, vascular - perineural invasion
5. Neuron-specific enolase (NSE), cytosolic
6. HCG-subunits, glycoproteins