Review Note
Last Update: 02/18/2024 05:30 AM
Current Deck: Part 2::1. Subsites::Gastrointestinal tract::Carcinoid tumour
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Fields:
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GI | Carcinoid | 1.6.5 | Specific sites | Stomach
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Definition
- Usually well-differentitated, non-functioning enterchromaffin-like cell carcinomas (ECL).
- 3 types are recognized:
- Type I (80%) – associated with autoimmune chronic atrophic gastritis Pathogenesis: ECL cells stimulated yb high gastrin levels associated with chronic atrophic gastritis.
- Type II (5%) – associated with MEN-1 and Zollinger-Ellison syndrome (caused by a separate gastrin-producing neoplasm, usually in the pancreas or samll intestine) Pathogenesis: Hypergastrinaemia caused by gastrin-producing neoplasm stimulates ECL cells in stomach
- Type III (15%) – sporadic. Ocucr in absence of atrophic gastritis, Zollinger-Ellison syndrome or MEN1.
- Also EC, serotonin-producing, G-cell, gastrin producing, small and large cell
Epidemiology
- I: Account for up to 20-40% of all GI carcinoids.
- A: Mean age of 60 years.
- S: Females much more common than males : 2.5:1.
- G: Higher incidence in Japan due to high incidence of chronic atrophic gastritis.
- Small cell is uncommon and is commoner in men.
Aetiology
- Gastrin: trophic for ECL-cells in humans and experimental animals.
- Autoimmune chronic atrophic gastritis:
- Due to antibodies to parietal cells of oxyntic mucosa. Leads to chronic atrophic gastritis and increased gastrin production.
Localisation
- ECL-cell carcinoids are found in mucosa of the body-fundus.
- Type I and II lesions are usually small and multiple.
- Type III lesions are generally solitary.
Pathology
Macro:
- Small circumscribed polyps
- Type II: thickened gastric wall due to hypertrophic-hypersecretory gastrophathy
- Type III larger and more infiltrative.
- ECL:
- Glandular, trabecular or rarely insular patterns
- Bland nuclei with salt and pepper chromatin, rare mitotic figures, prominent vessels, no necrosis
- Type III more aggressive with mitoses and necrosis
- EC-cell, serotonin producing: vary rare in stomach: rounded nests of closely packed small tumour cells with peripheral palisading.
- Gastrin-cell: thin trabecular-gyriform or solid nest pattern. Cells are uniform with scanty cytoplasm. Immunoreactive for gastrin.
- Small cell: small packed cells with hyperchromatic nuclei and nuclear moulding.
- Large cell neuroendocrine: large cells with organoid, nesting, trabecular, rosette-like and palisading patterns. Cytoplasm is more abundant and nuclei are more vesicular with prominent nucleoli.
- +ve for chromogranin, keratin, neuron-specific enolase; CK7-, CK20-
- Dense core secretory granules
BB
- Type I
- Indolent
- Usually <1cm size
- LN mets <5%
- Liver mets 2.5%
- Type II
- Indolent
- LN mets 30%
- Liver mets 10%
- Type III
- Most aggressive
- 70% have LN and distant mets
- Median survival 28 months
Management
- Type I
- Endoscopic resection for small tumours (majority) → endoscopic surveilance every 6-12 months
- Tumours increasing significantly in size / multiple tumours - consider antrectomy
- Type II
- Endoscopic resection → surveillance
- Can use octreotide/lanreotide if symptomatic
- Type III
- Radical resection and lymphadenectmoy
- Consider smaller wedge resection and no lymphadenectomy for smaller tumours with no evidence of nodal disease
Further information, not for memorising (no card)
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