Topic Completed: 1 August 2012

Minor changes: 13 November 2020

Copyright: 2003-2021,, Inc.

PubMed Search: stomach adenomas

Elliot Weisenberg, M.D.
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Cite this page: Weisenberg E. Adenomas. website. Accessed December 2nd, 2021.
Definition / general
  • 8 - 10% of all gastric polyps
  • Flat and depressed adenomas may occur
  • Relatively rare in Western populations; incidence increases with age, generally parallels that of gastric adenocarcinoma, M:F = 3:1
  • Associated with autoimmune gastritis, intestinal metaplasia, familial adenomatous polyposis
  • Considered to be analogous to colonic dysplasia-associated masses arising in setting of chronic inflammatory bowel disease, as they arise in a background of atrophic gastritis (metaplastic or autoimmune)
  • Only rarely associated with reactive / chemical gastropathy or post-antrectomy
Prognostic factors
  • Precursor lesion of gastric adenocarcinoma
  • Up to 30 - 40% contain focus of carcinoma at time of diagnosis, risk higher in larger tumors, especially if > 2cm, flat or depressed
  • Up to 30% risk of carcinoma in adjacent mucosa
  • 3% progress to carcinoma in 7 years (higher risk of carcinoma than colonic adenomas)
  • Intestinal type may have higher risk (Am J Surg Pathol 2002;26:1276)
  • APC mutations, MSI may occur
  • Complete excision, biopsy of nonpolypoid antrum and body, endoscopic surveillance, H. pylori eradication
Gross description
  • Usually single, up to 4 cm, sessile or pedunculated
  • Rarely are depressed mucosal lesions
Microscopic (histologic) description
  • Polypoid projections of dysplastic epithelium (by definition) with pseudostratification, nuclear abnormalities, mitotic figures overlying cystically dilated glands without dysplastic changes
  • Villous or tubular or both
  • Contains scattered endocrine cells, Paneth cells
  • Associated with atrophy and intestinal metaplasia
  • High grade: Cribriforming, irregularly shaped crowded glands with branching and budding and marked cytologic atypia

  • Intestinal type (majority):
    • Focal goblet cells or Paneth cells
    • More likely to show high grade dysplasia or adenocarcinoma within the polyp or a separate adenocarcinoma
    • Associated with intestinal metaplasia and H. pylori gastritis

  • Gastric type:
    • Lined entirely by gastric mucin cells on PAS / Alcian blue stain
    • Distributed throughout stomach, 82% solitary, not associated with coexisting carcinoma, background mucosa usually normal

  • Indeterminate: Cannot determine due to lack of mucin production
Positive stains
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