Suspicious aspects include a large nodule, depression and loss of pit pattern, and a masslike appearance (Fig. 2).13 The presence of any of these signs should lead to a careful consideration of whether endoscopic resection is appropriate. Unfortunately, these techniques, which are reasonably reliable in noncolitic colons, perform less well in colitis, because the scarring may lead to pseudodepression and inflammation distorts pit patterns. The nonlifting sign, which in combination with macroscopic

appearance gives a good estimate of likely invasion in the assessment of noncolitis-associated lesions, is by definition poor in colitis. Submucosal scarring impedes mucosal lift14 and also disrupts the mucosal layers needed

to clearly assess invasion at endoscopic ultrasonography. In noncolitis cases, submucosal scarring can Sorafenib clinical trial be seen in lesions with a previous attempt at resection, recurrence on a scar from previous EMR, or nongranular type LSTs.15 In colitis cases, if the patient has a tubular colon with evidence of scarring, postinflammatory polyps, loss of vascular pattern, or active inflammation, the submucosal scarring is likely to be severe and typically involves the entire lesion. Location of the lesion near technically difficult areas such as the appendix orifice, ileocecal valve, at a flexure, especially on the inside of the bend, and at the anal verge should also be considered.16 Although polyps check details in all these positions can be resected in noncolitic colon by experienced endoscopists, the technical difficulty is substantially increased. In combination with the other inherent challenges that colitic lesions present, this may make the likelihood of a successful resection so low that an Alanine-glyoxylate transaminase endoscopic attempt is not appropriate. The final stage is to consider endoscopic access. This is one of the few areas in which working in a colitic colon may have advantages because a scarred and tubular colon makes for a straight endoscope and associated

accurate tip movements and a lack of haustral folds to be negotiated. Before starting, endoscopists should be satisfied that they can easily reach all areas of the lesion with submillimeter precision. There is no specific combination of factors or scoring system that suggests that lesions are or are not safely and effectively resectable. Ultimately, at least at present, it comes down to the experience and judgment of the assessing endoscopist. Given the fine nature of these judgments, the authors recommend that if possible the endoscopist who is going to do the resection procedure should perform the endoscopy for lesion assessment before resection. Lifting or the failure of lifting of lesions in colitis is one of the major obstacles to resection.