Histopathologic features and fragmentation of polyps with cold snare defect protrusions.

BACKGROUND AND AIMS: Cold snare defect protrusions (CSDPs) include muscularis mucosa (MM) and submucosa tissue. CSDPs are thought to result from fragmentation of the specimen during shallow excision. Our aim in this study was to clarify whether CSDPs are associated with polyp fragmentation.

METHODS: We retrospectively analyzed 1026 neoplastic colorectal polyps resected by cold snare polypectomy for which the presence or absence of CSDPs was assessed from the endoscopic image. All prepared specimens were reviewed and assessed for the presence or absence of polyp fragmentation, and the proportion of MM on the stump was measured. In addition, the risk factors for CSDP occurrence were evaluated.

RESULTS: CSDPs occurred in 116 of the 1026 polyps (11.3%). Polyp fragmentation was significantly associated with the occurrence of CSDP on univariate analysis (odds ratio [OR], 3.74; P < .001) and multivariate analysis (OR, 3.13; P < .001). The proportion of MM >50% was significantly lower in the CSDP group than in the non-CSDP group (51.5% vs 70.9%, P < .001). CSDPs were significantly associated with a large polyp size (OR, 1.32; P = .007) and a large specimen size (OR, 1.24; P < .001) on multivariate analysis.

CONCLUSIONS: The occurrence of CSDP was associated with less MM on the stump and fragmentation of the specimen. Clinically, the presence of CSDP is a good indicator of polyp fragmentation.