Hyperplastic Polyp of the Stomach
Definition
- Reactive gastric polyp composed of irregular elongate and cystic foveolae set in an edematous stroma
Alternate/Historical names:
- Gastritis polyposa
- Hyperplasiogenic polyp
- Hyperplastic-adenomatous polyp
- Inflammatory hyperplastic polyp
- Regenerative polyp
- Retention polyp
Diagnostic Criteria
- May occur throughout the stomach
- 80% solitary
- Elongated, irregular, branched gastric pits
- Frequently cystic dilation of glands
- Lined by mature foveolar epithelium
- May be hypertrophic and resemble goblet cells
- May contain foci of intestinal metaplasia
- Rarely contains chief or parietal cells
- Edematous, inflamed stroma
- Frequent plasma cells, lymphocytes, eosinophils
- Frequent surface erosion
- Frequent vascular congestion
- May contain smooth muscle fibers from an irregular muscularis mucosae
- May be fibrotic
- Features may be similar to mucosal prolapse polyps of intestine
- Erosion of surface may produce atypical features
- Neutrophils and granulation tissue
- Regenerative epithelial atypia may be prominent
- May appear adenomatous in areas
- Atypical stromal cells may be present
- May have pleomorphic nuclei and atypical mitotic figures
- Usually arise in a setting of chronic gastritis
- Most frequently with Helicobacter
- Some cases with associated autoimmune gastritis
- Intestinal metaplasia frequently present
- Polyps of the esophagogastric junction not associated with chronic gastritis
- Adenomatous change may infrequently occur in the polyp
- Reported incidence 1-5%
- Usually associated with intestinal metaplasia
- Carcinoma is rarely reported to develop within the polyp
- One report describes nearly 2% incidence of carcinoma (Ahn 2014)
- Carcinoma may occur elsewhere in the stomach
- Reported incidence as high as 6% of cases
- May be synchronous or metachronous
- In most cases appears to reflect the background gastritis rather than derivation from the polyp
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting/last update: 11/29/09, 1/1/15
