| Theme | Prevalence of the IIc type colorectal neoplasm | |
|---|---|---|
| Title | Relevance of the depressed and flat adenoma in the United Kingdom | |
| Publish Date | 2004/01 | |
| Author | Bjorn J. Rembacken | Consultant Gastroenterologist, General Infirmary at Leeds Great George Street |
| [ Summary ] | The great majority of small adenomas never grow, advance or turn cancerous. The risk that a small sessile adenoma would harbour high-grade dysplasia is very small (0.1%). Although colonoscopy detect more than 95% of polyps, it appears to be less than perfect in protecting against the subsequent development of colorectal cancer. A likely reason for this is that some adenomas are either more difficult to detect or more aggressive than the polypoid adenomas. The lesions that we have detected in the United Kingdom are similar to those found in Japan. In addition, the frequency of polypoid, flat and depressed adenomas are strikingly similar. Apart from colonic polyps, what lesions must not be missed at colonoscopy? Perhaps the most frequently missed lesion is the flat, carpet-like tubulo-villous adenoma, usually found in the rectum or caecum. Although these lesions are large, they can easily be missed if the bowel preparation is sub-optimal. Small, smooth flat adenomas are less common but more difficult to detect as they only appear as small erythematous plaques. Small depressed lesions are uncommon but always significant as they commonly harbour early cancer even when small. We need to shift our attention away from simply finding and harvesting all diminutive colorectal lesions toward the detection of the more significant flat or depressed adenomas. |
|