Stomach
Polyps
Oxyntic gland adenoma


Topic Completed: 14 July 2020

Minor changes: 14 July 2020

Copyright: 2020, PathologyOutlines.com, Inc.

PubMed Search: Oxyntic gland (adenoma OR polyp)

Natalia Liu, M.D.
Hanlin L. Wang, M.D., Ph.D.
Page views in 2020 to date: 750
Cite this page: Liu N, Wang HL. Oxyntic gland adenoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/stomachoxynticglandadenoma.html. Accessed August 13th, 2020.
Definition / general
  • Benign gastric neoplasm composed of gland forming epithelial cells with predominantly chief cell differentiation resembling oxyntic glands
  • Risk of progression to gastric adenocarcinoma of fundic gland type with submucosal invasion
Essential features
Terminology
  • Many terms have been proposed for this polyp and its related invasive lesion, including:
    • Oxyntic gland polyp / adenoma
    • Oxyntic gland neoplasm
    • Gastric dysplasia of chief cell predominant type
    • Chief cell predominant gastric polyp
    • Chief cell hyperplasia with structural and nuclear atypia
    • Chief cell proliferation of the gastric mucosa
    • Chief cell adenoma
    • Gastric neoplasia of fundic gland (chief cell predominant) type
    • Gastric adenocarcinoma of fundic gland type
    • Gastric adenocarcinoma of fundic gland mucosa type
    • Gastric adenocarcinoma with chief cell differentiation
    • Chief cell predominant adenocarcinoma
ICD coding
  • ICD-O: 8210/2 - adenomatous polyp, high grade dysplasia
  • ICD-O: 8210/0 - adenomatous polyp, low grade dysplasia
  • ICD-11: 2E92.1 & XH3DV3 - benign neoplasm of stomach and adenoma, NOS
Epidemiology
Sites
  • Stomach, usually upper third (80%)
Etiology
  • Unknown
  • Not associated with Helicobacter pylori infection, atrophic gastritis or intestinal metaplasia
  • Questionable association with acid reduction therapy in patients with gastrointestinal reflux disease (World J Gastroenterol 2016;22:10523)
Clinical features
  • Usually incidental endoscopic finding
Diagnosis
  • Endoscopy
Prognostic factors
  • No recurrence following endoscopic excision in all reported cases
  • Risk of progression to submucosal invasion (gastric adenocarcinoma of fundic gland type) (World J Gastroenterol 2016;22:10523)
  • No risk of nodal or distant metastasis
Case reports
  • 49 year old man who was incidentally found to have a polypoid whitish elevation with a smooth surface in the gastric fundus measuring 1.1 cm (Case Rep Pathol 2016;2016:8646927)
  • 73 year old man with 6 mm slightly elevated, yellowish lesion with irregular surface vessels detected at the greater curvature of the upper body. (World J Gastroenterol 2015;21:5099)
Treatment
  • Complete excision
Clinical images

Contributed by Natalia Liu, M.D. and Hanlin L. Wang, M.D., Ph.D.
Flat raised nodule

Flat raised nodule

Gross description
Microscopic (histologic) description
  • Usually arising within the lower zone of oxyntic mucosa
  • Clusters of irregular glands typically separated by radiating wisps of smooth muscle (Mod Pathol 2020;33:206)
  • Dilated, branched, fused and anastomosed glands can be seen
  • Composed predominantly of columnar epithelial cells with chief cell differentiation characterized by basophilic cytoplasm and relatively uniform round nuclei (World J Gastroenterol 2016;22:10523)
  • Can have minor components of parietal cells and mucus cells
  • No more than mild nuclear atypia (World J Gastroenterol 2016;22:10523)
  • No mitosis, necrosis, desmoplasia or lymphovascular invasion
  • Mucosal surface may be spared and covered by gastric foveola and nonneoplastic oxyntic glands
  • If submucosal invasion is present, should be classified as gastric adenocarcinoma of fundic gland type
Microscopic (histologic) images

Contributed by Natalia Liu, M.D. and Hanlin L. Wang, M.D., Ph.D.
Architecture

Low power architecture

Irregular glands

Irregular glands

Predominantly chief cell differentiation

Predominantly chief cell differentiation

Cytology description
  • Bland cytologic features, uniform round nuclei, inconspicuous nucleoli, abundant basophilic cytoplasm (Mod Pathol 2020;33:206)
Molecular / cytogenetics description
  • Missense or nonsense mutations in Wnt / beta catenin signaling pathway (APC, CTNNB1, AXIN1, AXIN2) in ~50% of cases (Hum Pathol 2013;44:2438)
  • GNAS mutations in 19% of cases, almost mutually exclusive with mutations in Wnt / beta catenin pathway (Hum Pathol 2014;45:2488)
Sample pathology report
  • Stomach, polyp, biopsy:
    • Oxyntic gland adenoma (see comment)
    • Comment: The biopsy shows bland appearing glandular proliferation in the lower portion of the oxyntic mucosa. The epithelial cells lining the glandular structures exhibit features of chief cell differentiation. No features of invasive carcinoma are identified but there is insufficient submucosal tissue present for evaluation. The findings are consistent with a diagnosis of oxyntic gland adenoma, which is regarded as a benign lesion. Complete excision of the lesion is considered curative as no recurrence or metastasis has been documented in reported cases in the literature. Given its potential risk of progression to gastric adenocarcinoma of fundic gland type, endoscopic follow up is recommended.
Differential diagnosis
  • Well differentiated adenocarcinoma:
    • More prominent glandular anastomosis with lateral extension
    • More prominent nuclear atypia
    • Increased mitotic activity
    • Desmoplasia
    • Presence of intestinal metaplasia
    • Presence of dystrophic goblet cells
  • Well differentiated neuroendocrine tumor:
    • Nested or organoid growth pattern
    • Salt and pepper nuclear features
    • Positive immunostains for both chromogranin and synaptophysin
  • Pyloric gland adenoma:
    • Tightly packed pyloric type tubular glands
    • Cuboidal to low columnar epithelial cells showing pale or lightly eosinophilic cytoplasm with a ground glass appearance
    • Positive immunostains for both MUC5AC and MUC6
  • Fundic gland polyp:
    • Cystically dilated oxyntic glands lined by hypertrophic or flattened parietal cells admixed with chief cells and mucus cells
Board review style question #1

Which of the following is true about this gastric polyp?

  1. GNAS mutations occur in majority of this type of polyp
  2. It carries a risk of progression to submucosal invasion
  3. It is predominantly composed of columnar epithelial cells with parietal cell differentiation
  4. It is usually seen in the gastric antrum
  5. It stains positive for both MUC5AC and chromogranin
Board review answer #1
B. It carries a risk of progression to submucosal invasion

Comment Here

Reference: Oxyntic gland adenoma
Board review answer #2
What histologic feature is typically seen in an oxyntic gland adenoma?

  1. It frequently shows cystically dilated glands lined by hypertrophic parietal cells
  2. It frequently shows H. pylori gastritis in background gastric mucosa
  3. It frequently shows irregular glands separated by smooth muscle bundles
  4. It frequently shows lymphovascular invasion
  5. It frequently shows mitotic figures
Board review answer #2
C. It frequently shows irregular glands separated by smooth muscle bundles

Comment Here

Reference: Oxyntic gland adenoma
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