Importance of nonpolypoid (flat and depressed) colorectal neoplasms in screening for CRC in patients with IBD.

Patients with inflammatory bowel disease colitis have an increased risk of developing colorectal cancer compared with the general population. Colonoscopic surveillance remains challenging because the cancer precursor (dysplasia) can have a varied and subtle endoscopic appearance. Although historically the dysplasia was often considered endoscopically invisible, today with advanced endoscopic understanding, technique, and imaging, it is almost always visible. The frequency of different dysplasia morphologies and true clinical significance of such lesions are difficult to determine from retrospective series, many of which were performed prior to the current endoscopic era.