What is the recommended management for a patient with a colonoscopy showing a tubular adenoma (adenomatous polyp) with focal high-grade dysplasia (abnormal cell growth)?

Management of Tubular Adenoma with Focal High-Grade Dysplasia

Patients with tubular adenoma with high-grade dysplasia should have their next follow-up colonoscopy in 3 years, assuming complete removal of the adenoma and a high-quality baseline examination. 1, 2

Risk Stratification and Surveillance Recommendations

The presence of high-grade dysplasia in an adenoma places the patient in a higher-risk category that requires more intensive surveillance:

• High-grade dysplasia is considered an advanced adenoma feature that significantly increases the risk of developing colorectal cancer 1, 2
• The US Multi-Society Task Force on Colorectal Cancer and American Cancer Society guidelines specifically recommend a 3-year surveillance interval for patients with adenomas showing high-grade dysplasia 1
• This recommendation applies regardless of the size of the adenoma, as high-grade dysplasia is an independent risk factor for advanced neoplasia 1, 2

Verification of Complete Removal

Complete removal of the adenoma is critical for effective risk reduction:

• If the high-grade dysplasia adenoma was removed piecemeal, a shorter follow-up interval of 2-6 months is recommended to verify complete removal 1
• Once complete removal has been confirmed, the standard 3-year surveillance interval should be implemented 1
• Completeness of removal should be based on both endoscopic and pathologic assessments 1

Quality of Baseline Colonoscopy

The effectiveness of surveillance depends on the quality of the baseline examination:

• A high-quality baseline colonoscopy is defined as a procedure with:
  • Complete examination to the cecum with photo documentation of cecal landmarks 1
  • Adequate bowel preparation for visualization of polyps >5 mm 1
  • Minimum withdrawal time of six minutes from the cecum 1
• Inadequate bowel preparation or incomplete examination warrants a repeat colonoscopy before planning a long-term surveillance program 1

Subsequent Surveillance Intervals

The surveillance interval after the first follow-up colonoscopy depends on the findings:

• If the 3-year follow-up colonoscopy is normal or shows only 1-2 small tubular adenomas with low-grade dysplasia, the interval for subsequent examination should be extended to 5 years 1, 2
• If high-risk features are found again at the follow-up examination, another 3-year interval is recommended 1, 2

Clinical Significance and Prognosis

High-grade dysplasia in adenomas carries important prognostic implications:

• Patients with high-grade dysplasia in adenomas >1 cm have approximately a 7% risk of developing further adenomas with high-grade dysplasia or adenocarcinoma during follow-up 3
• The relative risk of advanced neoplasia within 5.5 years is 6.87 for patients with adenomas showing high-grade dysplasia compared to those with no neoplasia at baseline 4

Common Pitfalls and Caveats

• Incomplete removal: Failure to completely remove adenomas with high-grade dysplasia is associated with an increased risk of interval colorectal cancer 1
• Inadequate follow-up documentation: Endoscopists should make clear recommendations to primary care physicians about when the next colonoscopy is indicated 1
• Patient comorbidities: Discontinuation of surveillance colonoscopy should be considered in persons with serious comorbidities with less than 10 years of life expectancy 1
• Multiple adenomas: If the patient has multiple adenomas (>10) in addition to high-grade dysplasia, consider the possibility of an underlying familial syndrome and a shorter follow-up interval 1