gastric carcinoid

Classification

• type 1 lesions (65%)
  • occur in the setting of chronic atrophic gastritis
  • generally identified as incidental finding on endoscopy for non-specific gastrointestinal signs & symptoms
  • gastrin from G-cells in the gastric antrum stimulate growth of type 1 gastric carcinoid
• type 2 gastric carcinoid tumors occur in the context of ZE syndrome, MEN1, neurofibromatosis-1
• type 3 gastric carcinoid tumors (20%)
  • unfavorable prognosis

Epidemiology

• < 5% of carcinoid tumors

Laboratory

• serum gastrin
  • in type 1, serum gastrin may be as high as 550 pg/mL
  • serum gastrin elevated in type 2
  • serum gastrin is normal in type 3

Diagnostic procedures

• upper gastrointestinal endoscopy every 6-12 months for at least 3 years for small (<= 2cm) type 1 lesion

Complications

• metastasis
  • rare in type 1
  • more common in type 3

Management

• endoscopic resection of small (< 1 cm) type 1 gastric carcinoid tumors with < 5 lesions is curative & further treatment or surveillance is unnecessary
• for type 1 gastric carcinoid tumors <= 2 cm
  • upper gastrointestinal endoscopy every 6-12 months for at least 3 years
  • 5 year survival > 95%
• type 1 gastric carcinoid tumors > 5 cm
  • gastric antrectomy reduces G-cell mass that produces gastrin which stimulates growth of type 1 gastric carcinoid
• type 2 gastric carcinoid tumors
  • octreotide is used for control of flushing & diarrhea that occur in the context of ZE syndrome or MEN1 associated with type 2 tumors
• type 3 gastric carcinoid tumors
  • total gastrectomy

More general terms

• carcinoid (argentaffinoma)