We examined diminutive
colonic polyps to identify relationships between thermal
electrocoagulation or resection
trauma cytologic artifacts, type of thermal
electrocoagulation,
polyp size, and the interobserver variation among 3 pathologists. The 3 pathologists independently evaluated 119
colonic polyps 5 mm or less in maximum dimension for diagnosis and degree of thermal
electrocoagulation or resection
trauma cytologic artifacts. The maximum dimension of the
polyps and type of thermal
electrocoagulation were recorded. The average percentage of
polyps in which a definitive diagnosis could not be made because of cytologic artifacts was 16.5% (range, 11.8%-19.3%). Decreasing
polyp size was associated linearly with the inability to make a definitive diagnosis owing to cytologic artifacts.
Polyps smaller than 2 mm significantly more often could not be definitively diagnosed by at least 1 pathologist owing to cytologic artifacts, including some
polyps that were excised 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 make them especially susceptible to cytologically injurious forces.