Anal neoplasm in colonoscopy: What endoscopists need to know

The question of whether a colonoscopist should evaluate anal diseases is relevant. Endoscopists need to be aware of the possibility of anal neoplasms during a colonoscopy, as they can be easily overlooked if not properly examined. Specifically, one must clarify the responsibility of the colonoscopist in the diagnosis of anal neoplasms. Anal cancer is relatively rare, accounting for less than 2% of all cases annually. Owing to its rarity, population screening for anal cancer is not indicated, and monitoring is limited to high-risk groups. However, the number of anal cancer cases in high-risk groups has increased over the past four decades worldwide.

To assess the results of anal examinations performed during routine colonoscopy and emphasize the importance of diagnosing anal neoplasms.

This was a retrospective study of 16836 patients who were screened by colonoscopy and received a detailed anal examination by videoanoscopy between 2006 and 2024. Among several other findings, the presence of anal neoplasms and suspicious anal cancer lesions was observed. All examinations, including complete anal examination, inspection, digital rectal examination, and videoanoscopy, were performed, and images were recorded and reported. The examinations were individually viewed by the work group, and the findings were analyzed.

Among the 22676 colonoscopies performed, 16836 patients were identified, and 88 lesions suspected of neoplasia (0.52%) were found. Among them, there were 23 cases of neoplasia (0.13%), 9 cases of confirmed squamous cell carcinoma of the anal canal (0.05%), 5 cases of adenocarcinoma in the anal canal (0.03%), 3 cases of rare neoplasms (0.01%), and 6 cases of adenoma (0.03%).

The systematic performance of anal examinations and anoscopy during routine colonoscopy allows the identification of numerous anal diseases, including incidental cases of anal cancer.