The effect of electrothermal cautery-assisted resection of diminutive colonic polyps on histopathologic diagnosis

We examined diminutive colonic polyps to identify relationships between the rmal electrocoagulation or resection trauma cytologic artifacts, type of th ermal electrocoagulation, polyp size, and the interobserver variation among 3 pathologists. The 3 pathologists independently evaluated 119 colonic pol yps 5 mm or less in maximum dimension for diagnosis and degree of thermal e lectrocoagulation or resection trauma cytologic artifacts. The maximum dime nsion of the polyps and type of thermal electrocoagulation were recorded. T he average percentage of polyps in which a definitive diagnosis could not b e made because of cytologic artifacts was 16.5% (range, 11.8%-19.3%). Decre asing polyp size was associated linearly, with the inability to make a defi nitive diagnosis owing to cytologic artifacts. Polyps smaller than 2 mm sig nificantly more often could not be definitively diagnosed by at least 1 pat hologist owing to cytologic artifacts, including some polyps that were exci sed without thermal electrocautery. Interobserver variation increased with decreasing polyp dimension. Two millimeters seems to represent a cut point, below which the likelihood that a definitive diagnosis can be made can be increased if thermal electrocoagulation is used. This small size seems to m ake them especially susceptible to cytologically injurious forces.