Fundic Gland Polyp

Definition

Polyp occurring in the body/fundus of the stomach characterized by dilation of the fundic glands

Sessile polyp of the gastric fundus/body
- May be multiple
- Usually small <1 cm
Histologically identical polyps with varying clinical presentations
- Sporadic
  - Usually an incidental finding
- Familial adenomatous polyposis
  - Present in about half of FAP patients
- Following treatment with proton pump inhibitors (PPI)
  - Increased risk x 4
  - Increases with time
  - Frequently multiple
- Rare sporadic non-FAP polyposis
  - Defined as ≥10 polyps
  - Non-familial
Irregular proliferation of deep fundic glands
- Multiple budding from the glands
- Overlying pits shortened
Cystic dilation of glands
- Lining must include chief and parietal cells
- May include foveolar mucous cells
Smooth muscle may surround cysts
- Long thin bundles
- Extend from muscularis mucosae to superficial lamina propria
Scant stromal inflammation
Focal dysplasia may occur in polyps of FAP patients (40%)
- Rare in other patients (3%)
Carcinoma develops rarely in North American FAP patients with fundic gland polyps
- Marginally, if at all, increased above the general population
- Rare cases suggest origin from within a fundic gland polyp
- Carcinoma is much more frequent in Japan and Korea
  - Up to 10x increase over general population
Very rare familial cases of gastric carcinoma associated with gastric fundic gland polyposis without colonic polyposis or FAP

Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Original posting/last update : 11/29/09, 3/7/16