Can gastric polyps be tubular adenomas?

Gastric Tubular Adenomas: Characteristics and Management

Yes, gastric polyps can definitely be tubular adenomas, and these lesions require careful management due to their significant risk of malignant transformation. 1

Types and Prevalence of Gastric Adenomas

Gastric adenomas are a specific type of gastric polyp with the following characteristics:

• Usually single (82% of cases) and small (<2 cm)
• Most commonly located in the antrum and incisura angularis
• Have a velvety pink lobulated appearance endoscopically
• Can be sessile or pedunculated
• Prevalence in Western countries varies between 0.5% and 10% 1

Histologically, gastric adenomas can be classified as:

• Tubular adenomas (most common type, containing >80% tubular elements)
• Villous adenomas (containing >80% villous elements)
• Tubulovillous adenomas (mixture of tubular and villous elements) 1

Clinical Significance and Risk Factors

Gastric adenomas carry significant clinical importance:

• They are typically associated with a background of gastric atrophy and intestinal metaplasia 1
• Coexistence of synchronous gastric adenocarcinoma has been found in up to 30% of patients with gastric adenomas 1
• 50% of adenomas >2 cm contain foci of adenocarcinoma 1
• They have a high risk of progression to cancer 2

Risk factors for gastric adenomas include:

• Familial adenomatous polyposis (FAP) - patients with FAP have an increased risk for gastric adenomas 3
• Younger age (in FAP patients) 3
• Concomitant chronic gastritis 3

Endoscopic Features and Diagnosis

Gastric adenomas can be challenging to identify endoscopically:

• In the antrum, they appear flat and subtle
• In the body or fundus, they are polypoid and may be difficult to differentiate from fundic gland polyps 3
• NBI (Narrow Band Imaging) features include:
  • Paler color relative to background mucosa
  • Slit-like crypt opening
  • Regular white opaque substance (corresponds to absorbed subepithelial lipid droplets)
  • Tubular, villous, or ridged mucosal structure 1

Management Recommendations

All gastric adenomas should be completely resected when clinically appropriate due to their significant risk of progression to cancer. 2

Management algorithm:

1. Confirm diagnosis of adenoma and degree of dysplasia histologically before treatment
2. Carefully evaluate the entire stomach to identify:
   • Synchronous neoplasia (present in 30% of cases)
   • Gastric atrophy
   • Intestinal metaplasia 1
3. Perform endoscopic resection:
   • For sessile polyps >15 mm: En bloc excision with endoscopic submucosal dissection (ESD) is advisable as the risk of invasive neoplasia is high and ESD reduces recurrence compared to EMR
   • For smaller lesions: Snare polypectomy or endoscopic mucosal resection (EMR) 2
4. Follow-up surveillance:
   • Perform follow-up gastroscopy 6-12 months after endoscopic resection
   • Continue yearly surveillance gastroscopy depending on the number of polyps, their size, and the highest grade of dysplasia 1

Important Caveats and Pitfalls

• Gastric adenomas can be easily missed during endoscopy due to their subtle appearance, especially in the antrum 3
• Endoscopists should have a high degree of suspicion for gastric adenomas and a low threshold to biopsy suspicious lesions 3
• Enhanced endoscopic imaging (NBI, i-Scan, FICE) should be used when there is diagnostic uncertainty following white light examination 2
• Proper documentation of polyp characteristics (number, location, size, morphology) is essential for appropriate management 2
• Adenomas in the setting of FAP may be particularly difficult to identify as they can be masked by numerous fundic gland polyps 3

By following these recommendations, clinicians can appropriately manage gastric tubular adenomas and reduce the risk of progression to gastric cancer, thereby improving patient morbidity, mortality, and quality of life.