Clinical and endoscopic evaluations of sessile serrated adenoma/polyps with cytological dysplasia

Background and Aim Although sessile serrated adenoma/polyps (SSA/Ps) are considered to be premalignant lesions and rapidly progress to carcinomas after they develop cytological dysplasia (CD), a treatment strategy for SSA/Ps in Asian countries is still being debated and has not yet been established. The present study aimed to propose a treatment strategy for SSA/Ps. Methods Histopathological data of patients, who underwent colonoscopy at our center between January 2011 and December 2016, were reviewed. Data of patients with ≥ 1 SSA/P were retrieved, and clinicopathological characteristics were retrospectively analyzed. Results A total of 281 patients with 326 SSA/Ps, including 258 patients who had 300 SSA/Ps without CD (SSA/Ps‐CD[−]) and 23 patients who had 26 SSA/Ps with CD (SSA/Ps‐CD[+]), were evaluated in this study. Although SSA/Ps‐CD(+) were often found in older female patients and in the proximal colon, there were no significant differences between SSA/Ps‐CD(−) and SSA/Ps‐CD(+). Endoscopic morphological findings, such as large or small nodules on the surface and partial protrusion of the lesions, were significantly more common in SSA/Ps‐CD(+) than in SSA/Ps‐CD(−). Although the diagnostic ability of nodule/protrusion in lesions to predict CD within SSA/Ps was very high with an accuracy of 93.9% and a negative predictive value of 95.4%, sensitivity was low at 46.2%. SSA/Ps‐CD(+) were significantly larger than SSA/Ps‐CD(−), and the rate of CD within SSA/Ps significantly increased with lesion size (≤ 5 mm, 0%; 6–9 mm, 6.0%; ≥ 10 mm, 13.6%). Conclusion The study proposes removing all SSA/Ps ≥ 6 mm in order to remove high‐risk SSA/Ps‐CD(+), with high sensitivity.