Prevalence and Anatomic Distribution of Serrated and Adenomatous Lesions in Patients with Inflammatory Bowel Disease.

Background. Sessile serrated adenomas/polyps (SSA/Ps) and traditional serrated adenomas (TSAs) have not been well characterized in patients with inflammatory bowel disease (IBD). This study assesses the prevalence and anatomic distribution of SSA/Ps, TSAs, and conventional adenomas/dysplasia (Ad/Ds) in IBD patients. Methods. IBD patients with serrated, adenomatous, or hyperplastic lesions between 2005 and 2009 were identified in the regional tertiary-care hospital database. Clinicopathological information was reviewed and the histology of biopsies was reevaluated. Results. Ninety-six Ad/Ds, 25 SSA/Ps, and 4 TSAs were identified in 83 patients. Compared to Ad/Ds, serrated lesions were more prevalent in females (p = 0.046). The prevalence of Ad/Ds was 4.95%, SSA/Ps was 1.39%, and TSAs was 0.31%. No relationship was identified between lesion type and IBD type. Comparing all IBD patients, the distribution of lesion types was significantly different (p = 0.02) with Ad/Ds more common distally, SSA/Ps more common proximally, and TSAs evenly distributed. Among Crohn's disease (CD) patients, a similar distribution difference was noted (p < 0.001). However, ulcerative colitis (UC) patients had a uniform distribution of lesion types (p = 0.320). Conclusions. IBD patients have a lower prevalence of premalignant lesions compared to the general population, and the anatomic distribution of lesions differed between CD and UC patients. These findings may indicate an interaction between lesion and IBD pathogenesis with potential clinical implications.