A morphologic analysis of sessile serrated polyps observed during routine colonoscopy (with video)

Background: Proximal colorectal cancer may arise from sessile serrated polyps (SSPs), which are often inconspicuous during colonoscopy. The gross morphologic characteristics of SSPs have not been systematically described, and this omission may contribute to colonoscopists overlooking them.

Objectives: To analyze the gross morphologic characteristics of SSPs detected during routine colonoscopy.

Design: Retrospective analysis of high-resolution endoscopic video clips depicting SSPs in situ.

Setting: Outpatient gastroenterology practice.

Patients: A total of 124 subjects undergoing surveillance or screening colonoscopy after split-dose bowel preparation.

Interventions: Analysis of 158 SSPs performed by using validated descriptors.

Main outcome measurements: The prevalence of morphologic characteristics related to polyp shape, color, and texture.

Results: A total of 158 SSPs were studied. For 7 visual descriptors, a κ coefficient of ≥ 0.7 was achieved, indicating good to excellent intraobserver agreement. The most prevalent visual descriptors were the presence of a mucous cap (63.9%), rim of debris or bubbles (51.9%), alteration of the contour of a fold (37.3%), and interruption of the underlying mucosal vascular pattern (32.3%). The most common "sentinel signs" were the presence of a mucous cap and alteration of the contour of a mucosal fold (each 24.6%), rim of debris or bubbles (21.7%), and a dome-shaped protuberance (20.3%). When comparing SSPs with adenomatous polyps, the frequencies of 5 of 7 morphologic characteristics and the distribution of sentinel signs differed (P < .01).

Limitations: Single-site, retrospective analysis.

Conclusions: SSPs exhibit distinct, variable morphologic characteristics. Many do not display classic features such as a mucous cap. Enhanced appreciation of these morphologic characteristics may improve SSP detection and thereby colorectal cancer prevention.