Simple SummaryInflammatory bowel disease (IBD) patients with long-standing and extensive colitis have an enhanced risk of developing colorectal cancer and, therefore, they must undergo surveillance colonoscopies at regular intervals. The presence of polyps in an area inside colitis, commonly referred to as “pseudopolyps”, seems to increase the risk of CRC in IBD, but it is unclear whether there are some subsets of pseudopolyp-like lesions that might eventually undergo neoplastic transformation. In the present study, we evaluated the frequency and predictors of dysplasia in IBD-associated pseudopolyp-like colorectal lesions. Our study shows that more than one-fifth of pseudopolyp-like lesions are dysplastic, and the majority of such neoplastic lesions are greater than 5 mm and located in the right colon. Therefore, lesions with such morphologic features must be removed even if they are present in an area inside colitis.AbstractCurrent endoscopic surveillance programs do not consider inflammatory bowel disease (IBD)-associated post-inflammatory polyps (pseudopolyps) per se clinically relevant, even though their presence seems to increase the risk of colorectal cancer (CRC). However, it remains unclear whether the link between pseudopolyps and CRC is indirect or whether some subsets of pseudopolyp-like lesions might eventually undergo neoplastic transformation. This study aimed to assess the frequency and predictors of dysplasia in pseudopolyp-like lesions in a population with long-standing colonic IBD. This was a retrospective, single-center study including patients with a colonic IBD (median disease duration of 192 months) and at least a pseudopolyp-like lesion biopsied or resected in the period from April 2021 to November 2022. One hundred and five pseudopolyps were identified in 105 patients (80 with ulcerative colitis and 25 with Crohn’s disease). Twenty-three out of 105 pseudopolyp samples (22%) had dysplastic foci, and half of the dysplastic lesions were hyperplastic. Multivariate analysis showed that the age of the patients (odds ratio (OR) 1.1;p= 0.0012), size (OR 1.39;p= 0.0005), and right colonic location (OR 5.32;p= 0.04) were independent predictors of dysplasia, while previous exposure to immunosuppressors/biologics and left colonic location of the lesions were inversely correlated to dysplasia (OR 0.11;p= 0.005, and OR 0.09;p= 0.0008, respectively). No differences were seen between ulcerative colitis and Crohn’s disease patients. Lesions with a size greater than 5 mm had a sensitivity of 87% and a specificity of 63% to be dysplastic. These data show that one-fourth of pseudopolyp-like lesions evident during surveillance colonoscopy in patients with longstanding IBD bear dysplastic foci and suggest treating such lesions properly.