What is the recommended interval for colonoscopy follow-up after removal of a 1.2cm tubular adenoma?

Recommended Colonoscopy Surveillance Interval After Removal of 1.2cm Tubular Adenoma

The correct answer is C: 3 years. A 1.2cm tubular adenoma meets high-risk criteria (adenoma ≥10mm), mandating surveillance colonoscopy at 3 years after complete removal 1, 2, 3.

Risk Stratification

This patient's polyp characteristics place them in the high-risk category based on size alone:

• Size ≥10mm (1.2cm in this case) is the defining high-risk feature 1
• The tubular histology and presumed low-grade dysplasia (standard for tubular adenomas unless otherwise specified) do not change this classification 2, 3
• A single high-risk adenoma requires the same 3-year surveillance as multiple high-risk features 1

Evidence-Based Surveillance Algorithm

For High-Risk Adenomas (This Patient):

• 3-year surveillance colonoscopy is the standard recommendation after complete removal of any adenoma ≥10mm 1, 2, 3, 4
• This applies regardless of whether the patient has 1 or multiple adenomas, as long as at least one meets high-risk criteria 1

Critical Prerequisite:

• This 3-year interval assumes complete removal of the adenoma with high-quality baseline colonoscopy (cecal intubation with photo documentation, adequate bowel preparation, minimum 6-minute withdrawal time) 2, 3, 4
• If piecemeal removal was performed, short-interval follow-up at 2-6 months is needed first to verify complete removal 1

Why Not the Other Options?

Option A (No need): Incorrect

• Only applies to small rectal hyperplastic polyps, not adenomas 1

Option B (6 months): Incorrect

• Reserved only for sessile adenomas removed piecemeal to verify complete removal 1
• Not indicated for standard polypectomy of a 1.2cm polyp

Option D (10 years): Incorrect

• Only appropriate for low-risk adenomas (1-2 tubular adenomas <10mm with low-grade dysplasia) 1, 2, 3, 4
• This patient's 1.2cm adenoma exceeds the size threshold for low-risk classification

Subsequent Surveillance Strategy

If the 3-year surveillance shows:

• Normal findings or only 1-2 small tubular adenomas (<10mm): Extend next interval to 5 years 1, 2, 3
• High-risk adenomas again detected: Maintain 3-year surveillance intervals 2, 3, 4

Common Pitfalls to Avoid

• Don't confuse size thresholds: The critical cutoff is 10mm, not 1cm—this patient's 1.2cm (12mm) adenoma clearly exceeds this 1, 2
• Don't apply low-risk intervals to high-risk findings: The 7-10 year interval only applies to 1-2 adenomas <10mm 1, 2, 3
• Don't recommend surveillance without confirming quality baseline examination: Inadequate bowel prep or incomplete examination invalidates risk stratification and requires repeat colonoscopy before establishing surveillance schedule 2, 4