Colitis-Associated Dysplasia in Inflammatory Bowel Disease: Features and Endoscopic Management

Patients with long-standing inflammatory bowel disease (IBD) involving the colon are at higher risk of developing colorectal dysplastic or neoplastic lesions. While from sporadic colorectal cancer follows an "adenoma-carcinoma" sequence, IBD colitis-associated carcinogenesis is mainly related to an "inflammation-dysplasia-carcinoma" sequence. Currently, specific endoscopic surveillance strategies involving dye spray and virtual chromoendoscopy have been standardized, aiming for early CRC diagnosis. When detected, colitis-associated dysplasia should be classified according to standard classification, thus allowing for better treatment. Indeed, most IBD-associated dysplastic lesions can be treated with endoscopic resection, even though available procedures are usually more challenging than those in the general population. The higher frequency of severe submucosal fibrosis and the difficulty in the definition of lesions' margins account for this issue. Current endoscopic resection techniques include polypectomy, endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). Recent evidence suggests the relevance of en bloc resection, as this may be associated with lower rates of recurrence. Therefore, particularly for larger (>20 mm) lesions, ESD should be preferred, even though it is considered the most difficult technique due to frequent severe submucosal fibrosis. Considering the growing number of new endoscopic resective techniques, including underwater EMR or ESD, which in the general population have been suggested to lower procedure-related risks and may also allow a larger spread of advanced endoscopic resection in IBD. However, additional data are needed to assess the medium- and long-term efficacy of endoscopic resection of visible dysplasia in IBD patients, which are burdened by a high risk of local and, more importantly, metachronous recurrence.