Clinical and endoscopic characteristics of sessile serrated lesions with dysplasia/carcinoma

Abstract

Background/aims: Some sessile serrated lesions (SSLs) progress into dysplasia and colorectal cancer, however, the clinical and endoscopic characteristics of SSLs with dysplasia remain to be determined. In this study, we elucidated these characteristics in SSLs with dysplasia/carcinoma, compared with those of SSLs without dysplasia.

Methods: We retrospectively collected the clinical, endoscopic, and pathological data of 254 SSLs from 216 patients endoscopically resected between January 2009 and December 2020.

Results: All SSLs included 179 without dysplasia and 75 with dysplasia/carcinoma, including 55 with low-grade dysplasia, 10 with high-grade dysplasia, and 10 with submucosal cancer. In clinical characteristics, SSLs with dysplasia/carcinoma were significantly associated with advanced age, metabolic diseases, and high-risk adenomas. In endoscopic characteristics, SSLs with dysplasia/carcinoma were significantly associated with the distal colon, large size, polypoid morphology, surface-changes, no mucus cap, and narrow-band imaging international colorectal endoscopic classification (NICE) type 2/3. In the multivariate analysis, high-risk adenomas (odds ratio [OR], 2.98; p = 0.01), large size (OR, 1.18; p < 0.01), depression (OR, 11.74; p = 0.03), and NICE type 2/3 (OR, 14.97; p < 0.01) were significantly associated with SSLs with dysplasia/carcinoma.

Conclusion: SSLs had a higher risk of dysplasia in the distal colon than in the proximal colon. SSLs with large size, depression, and adenomatous surface-patterns, as well as those in patients with high-risk adenomas, increased the risk of dysplasia/ carcinoma. This suggests that the clinical and endoscopic characteristics can aid in the diagnosis and management of SSLs with dysplasia/carcinoma.

Keywords: Carcinoma; Clinical and endoscopic characteristics; Dysplasia; Sessile serrated lesions.

Figure 1

Flow chart of patient enrolment. EMR, endoscopic mucosal resection; ESD, endoscopic submucosal dissection; NBI, narrow-band imaging.

Figure 2

Five surface findings of sessile serrated lesions with/without dysplasia/carcinoma. (A, B) Granular surface. (C, D) Focal nodular elevation. (E, F) Depression. (G, H) Redness. (I, J) Mucus cap.

Figure 3

A case of sessile serrated lesion with invasive carcinoma. (A, B) Endoscopic findings; (A) flat elevated lesion with some hyperemic and granular surfaces and (B) in near focus view, narrow-band imaging (NBI) international colorectal endoscopic classification (NICE) type 1/Kudo pit pattern (KPP) II-O (yellow arrows) and NICE type 2/3/KPP III/IV (blue arrows). (C, D) Gross findings of resected specimen; (C) 20 mm sized flat and elevated lesion with focal nodular elevation and (D) a depression in focal nodular elevation. (E–G) Histologic findings with hematoxylin and eosin staining (H&E) of the resected specimen; (E) transitional area from sessile serrated lesion to dysplasia (yellow arrow) and invasive carcinoma (blue arrow) (H&E, ×1), (F) high-power field of the right side of (E), serrated changes (yellow arrow) and architectural distortion like dilation and branching (blue arrow) of crypt in basal layer near muscularis mucosa (H&E, ×60), and (G) high-power field of the left side of (E), moderately differentiated adenocarcinoma invading the submucosal layer (blue arrows) (H&E, ×200).