Hyperplastic, adenomatous, and hamartomatous
•
Fundic gland polyps: Now most common type
Associated with use of proton pump inhibitor (PPI) medication
Sometimes considered a variant of hyperplastic polyps
•
Hyperplastic polyps
Virtually no malignant potential
Typical: Small, multiple, sessile (< 1 cm)
Location: Fundus and body
•
Adenomatous polyps
Less common (< 20% of benign polyps)
Increased risk of malignant change
Usually solitary, > 1 cm
•
Hamartomatous polyps
Peutz-Jeghers syndrome
Can occur as isolated finding (sporadic)
TOP DIFFERENTIAL DIAGNOSES
•
Retained food and pills
•
Gastric carcinoma (polypoid type)
•
Gastric metastases and lymphoma
•
Gastric gastrointestinal stromal tumor
•
Ectopic pancreatic tissue
CLINICAL ISSUES
•
Prevalence of gastric polyps in patients who have upper endoscopy = 6% (2009 study)
•
Fundic (77%), hyperplastic (17%), malignant (2%), adenomas (< 1%)
•
Much higher percentage of fundic polyps than in earlier studies
Caused by increased use of PPI medications
•
Syndromic polyps have high association with cancer risk in stomach and other organs
e.g., familial polyposis, Peutz-Jeghers syndrome
TERMINOLOGY
Definitions
•
Protruding, space-occupying lesion within stomach
Encompass a broad spectrum of conditions that may originate in gastric mucosa or submucosa
IMAGING
General Features
•
Best diagnostic clue
Radiolucent filling defect, ring shadow, or contour defect on barium study
•
Morphology
Hyperplastic polyps: Smooth, sessile
–
Fundic gland polyps: Always sessile, multiple, small
Adenomatous polyps: Usually single with lobulated or cauliflower-like surface
Hamartomas: Cluster of broad-based polyps
•
Other general features
Polyps classified based on pathology
Fundic gland polyps
–
Variant of hyperplastic polyps (< 1 cm)
–
Have become most common type of gastric polyp
–
Associated with use of proton-pump inhibitor medication
Hyperplastic polyps
–
Virtually no malignant potential
–
Typical: Small, multiple, sessile (< 1 cm)
Location: Fundus and body
–
Atypical large: Solitary, pedunculated (2-6 cm), location in body and antrum
–
Atypical giant: Polyp (6-10 cm) multilobulated mass, location in body and antrum
Adenomatous polyps
–
Less common (< 20% of benign polyps); dysplastic lesions
–
Increased risk of malignant change via adenoma-carcinoma sequence
–
Usually solitary, occasionally multiple, > 1 cm
Location: Mostly antrum > body
–
Histologically: Tubular (75%), tubulovillous (15%), villous (10%)
–
Gastric adenomatous polyps 30x less common than gastric cancer
–
Carcinoma in situ and invasive carcinoma: Seen in 50% of adenomatous polyps > 2 cm
–
30-40% associated with atrophic gastritis, pernicious anemia, and cancer
–
Higher risk of coexisting gastric cancer than risk of malignant change in polyp
Polyposis syndromes involving stomach
–
Familial adenomatous polyposis (FAP) syndrome
> 50% of patients have gastric adenomatous or fundic gland polyps
–
Hamartomatous polyposis (e.g., Peutz-Jeghers syndrome [PJS])
Have increased risk of gastric and other cancers
–
Cronkhite-Canada, Cowden, etc.
All rare but associated with gastric polyps