Colorectal dysplasia in inflammatory bowel disease: a clinicopathologic perspective.

Surveillance for neoplasia in colitis is the most challenging diagnostic colonoscopic procedure. The detection and treatment of colorectal dysplasia in inflammatory bowel disease remain problematic to the point that unsuspected colorectal cancers (CRCs) are still identified. Excellent bowel preparation and use of high-resolution colonoscopes with chromoendoscopy facilitate the detection and characterization of subtle neoplasia. This approach is superior to taking random biopsy specimens and should be the standard of care for surveillance but requires adequate training. Suspicious lesions should be assessed carefully and described using objective terminology. The terms dysplasia-associated lesions/masses and flat dysplasia are best avoided because they may be open to misinterpretation. Most suspicious lesions detected during surveillance can be removed endoscopically, precluding the need for surgery. Nevertheless, endotherapy in colitis can be difficult as a result of underlying inflammation and scarring. Lesions that are not endoscopically resectable need to be removed surgically, although the possibility that some lesions might be amenable to local resection (including lymphadenectomy) rather than subtotal colectomy may need to be re-evaluated. Despite surveillance programs, patients still present clinically with CRC. This may occur because lesions are missed (possibly because of the failure to use optimal techniques), lesions are not adequately removed, patients fail to return for colonoscopy, or CRCs arise rapidly in mucosa that is minimally dysplastic and the CRCs are not recognized as being potentially invasive even on biopsy. Future advances in, for example, stool DNA assays, use of confocal endomicroscopy, or use of endoscopic ultrasound, may help in the identification of high-risk patients and the assessment of dysplastic lesions.