Neuroendocrine tumors of the gastroentero-pancreatic systemD44.9
Synonym(s)
DefinitionThis section has been translated automatically.
The gastroenteropancreatic neuroendocrine tumors (acronym "GEP-NET") which are also known under various terms such as carcinoid, islet cell tumor or gastrinoma, among others. GEP-NETs originate from the neuroendocrine cells of the gastroenteropancreatic (GEP) system. This endocrine cell system and its tumors are characterized by the expression of cell type-specific peptide hormones and different types of tumors. neurotransmitters such as synaptophysin and chromogranin-A. The increased secretion of these hormones often leads to path-breaking hypersecretion syndromes (e.g. flush symptoms) with corresponding clinical symptoms. Such functionally active GEP-nets are called gastrinoma, insulinoma or glucagonoma depending on the secretion product.
ClassificationThis section has been translated automatically.
WHO classification of NETs/proliferation-based grading:
- Highly/well differentiated neuroendocrine tumor (G1) -Ki-67 index: =/<2%
- Highly/well differentiated neuroendocrine tumor (G2) -Ki-67-Index: 3-20%
- Low/well differentiated neuroendocrine tumor (G3) =NEC -Ki-67 index > 20% (large-cell and small-cell variant)
Classification of NETs according to localization:
- NET of the stomach
- NET of the duodenum and proximal jejunum
- NET of the ileum and the appendix
- NET of the colon and rectum
- NET of the pancreas
Occurrence/EpidemiologyThis section has been translated automatically.
The incidence of gastroenteropancreatic neuroendocrine tumors is estimated at 1-2/100,000 per year.
Clinical featuresThis section has been translated automatically.
The clinical picture of neuroendocrine tumors is directly dependent on their respective secretion product:
- Insulinoma (secretion of insulin)
- Glucagonoma (secretion of glucagon)
- Somatostatinoma (secretion of somatostatin)
- VIPom (secretion of vasoactive intestinal polypeptide)
- Gastrinom (secretion of gastrin)
- NET of jejunum, ileum, ascending colon (secretion of serotinin, neurotensin; in metastasis flush syndrome)
- NET of colon transversum, colon descendens, sigmoid colon, rectum (non-functional secretion of chromium granin A)
DiagnosisThis section has been translated automatically.
The clinical symptoms of patients with GEP-NET depend on the hormonal activity of the tumours and on the localisation and extent of the tumour:
- Insulinoma: recurrent hypoglycaemia, which manifests itself in adrenergic symptoms such as tachycardia, anxiety, sweating and palpitations. In the absence of carbohydrate intake, a neuroglycopenic symptom with loss of consciousness may occur.
- Gastrinomas: recurrent duodenal ulcerations and gastroesophagial reflux are the leading symptoms of duodenal or pancreatic gastrinomas. Rarely only diarrhea occurs.
- Glucagonoma: the combination of necrolytic-migratory erythema, pronounced weight loss and glucose intolerance characterize the glucagonoma.
- VIPom (VIP = acronym for vasocative intestinal polypeptide): abdominal cramps, aqueous diarrhoea with consecutive dehydration, weight loss.
- NET of the ileum and appendix: diarrhea, abdominal cramps and typical flush, especially in the face, neck and thorax region, are symptoms of metastasized ileal NET. The solitary appendical carcinoid is a mostly benign incidental finding.
LiteratureThis section has been translated automatically.
- Perren A et al (2010): Classification and pathology of gastroenteropancreatic neuroendocrine tumors. Visceralmed 26: 234-240