What is the recommended follow-up colonoscopy screening interval for a 40-45 year-old man with a history of a 1.5 cm tubular adenoma, where 1.3 cm of the lesion was removed during the procedure?

Incomplete Polypectomy Requires Short-Interval Follow-Up at 3-6 Months

Given that only 1.3 cm of a 1.5 cm tubular adenoma was removed (leaving 0.2 cm of residual polyp tissue), the next colonoscopy should be performed at 3-6 months to verify complete removal before establishing a standard surveillance schedule. 1

Critical Issue: Incomplete Resection

• The scenario describes incomplete polypectomy—only 86% of the lesion was removed (1.3 cm of 1.5 cm), leaving residual adenomatous tissue in the colon 1
• Patients with sessile adenomas removed piecemeal or incompletely should have follow-up at short intervals (2-6 months) to verify complete removal 1
• This short-interval recommendation takes precedence over standard surveillance intervals because incomplete removal is a known risk factor for interval colorectal cancer 1

Why Standard Surveillance Intervals Don't Apply Here

• The standard 3-year surveillance interval for adenomas ≥10 mm explicitly assumes complete removal of neoplastic tissue at baseline 1
• If there is any question about complete removal, early follow-up colonoscopy is warranted rather than waiting 3 years 1
• The 2020 US Multi-Society Task Force guidelines emphasize that high-quality baseline examination with complete polyp removal is a prerequisite for applying standard surveillance intervals 1

Algorithm for This Clinical Scenario

1. Immediate step: Schedule colonoscopy at 3-6 months to assess the polypectomy site 1
2. At 3-6 month colonoscopy:
   • If residual adenoma is found, remove it completely 1
   • Document complete removal both endoscopically and pathologically 1
3. After confirmed complete removal:
   • Since the original adenoma was ≥10 mm (1.5 cm), schedule next surveillance at 3 years 1
   • This 3-year interval applies because adenomas ≥10 mm carry 2-3 times higher risk of advanced neoplasia at follow-up compared to smaller adenomas 1

Common Pitfall to Avoid

• Do not apply the 3-year surveillance interval immediately after incomplete polypectomy 1
• The British Society of Gastroenterology specifically warns that piecemeal resection requires 6-month follow-up before initiating standard surveillance 2
• Failure to verify complete removal can result in missed residual adenomatous tissue that may progress to cancer during what the patient believes is an appropriate surveillance interval 1

Answer to Multiple Choice Question

The correct answer is A) 3-6 months 1, 2

The other options would only be appropriate if complete removal had been documented at the initial procedure, which is not the case here 1