American Board of Internal Medicine (ABIM) Certification Practice Exam

What indicates the need for repeat colonoscopy in patients with high-grade dysplasia adenomas?

1. 6 months

2. 1 year

3. 3 years

4. 5 years

The correct answer is: 3 years

The indication for repeat colonoscopy in patients with high-grade dysplasia adenomas is typically 3 years after the initial identification of these lesions. High-grade dysplasia in adenomas is associated with an increased risk of colorectal cancer, which warrants closer surveillance. The rationale behind this timeframe stems from guidelines established by various gastroenterology associations, which recommend that after the detection of high-grade dysplasia, a follow-up colonoscopy should be performed to monitor for any progression of dysplasia or the presence of additional neoplastic lesions. A 3-year interval allows for an adequate period to monitor changes in the adenoma status, ensuring that any developing malignancies can be detected and managed in a timely manner. In contrast, shorter intervals, like 6 months or 1 year, may lead to unnecessary procedures without clear benefit, while a longer interval, such as 5 years, may increase the risk of progression to colorectal cancer due to insufficient monitoring. Thus, the 3-year follow-up aligns with best practices in colon cancer surveillance following the detection of high-risk adenomatous lesions.