Variation between Pathological Measurement and Endoscopically Estimated Size of Colonic Polyps

Abstract

Background and Aims: Accurate determination of colonic polyp size is vital to an appropriate surveillance. The main aim of this study was to evaluate variation between the polyp size reported by the endoscopist and its pathological measurement. Methods: A retrospective analysis of all colonic adenomatous polyps resected in a 12-month period was performed at our center. Endoscopic and pathological size for each polyp were compared, and overestimation rates, underestimation rates, and endoscopic-pathological variation (EPV) were calculated. Results: Among the 573 polyps that were included, the mean endoscopic and pathological sizes were 8.00 and 6.66 mm, respectively. The most frequent error, in 62.1%, was overestimation by the colonoscopist. Overestimation and EPV were associated with resection technique (higher in endoscopic mucosal resection and smaller with biopsy forceps) and colonoscopist. They were not associated with years of experience in colonoscopy. Overestimation was more frequent in larger polyps. Conclusions: Our study shows significant discordance between endoscopic and pathological size of colonic polyps with a clear tendency for endoscopic overestimation. Larger polyps are more difficult to accurately assess than smaller ones. This propensity for error was not related to colonoscopist’s years of experience and seems to be an individual tendency.

Underwater vs Conventional Endoscopic Mucosal Resection of Large Sessile or Flat Colorectal Polyps: A Prospective Randomized Controlled Trial

“…Second, lesion size was estimated macroscopically, but it is known that endoscopists usually overestimate polyp size by as much as 20%, especially when the lesion is larger than 1 cm. [64][65][66] To overcome this limitation, lesion size was measured with an opened snare. Third, all patients remained in the hospital for a minimum of 48 hours after the procedure; adverse events within this time were systematically monitored.…”

What size cutoff level should be used to implement optical polyp diagnosis?

“…Study limitations include the post hoc nature of the analysis, and the fact that polyp size was based on endoscopists' measurements. Endoscopists tend to overestimate polyp size compared with the size measured during pathological examination [32,33]. However, the method reflects general clinical practice and will remain a limitation until better techniques are widely available to improve realtime polyp measurement during colonoscopy.…”

Usefulness and Educational Benefit of a Virtual Scale Endoscope in Measuring Colorectal Polyp Size

“…Nonetheless, most endoscopists rely on subjective visual estimation to determine CPS during colonoscopy. Previous reports have indicated that endoscopists, particularly those with less experience, often make incorrect CPS estimations [7][8][9][10][11][12]. A lack of information about the distance between the tip of the colonoscope and the polyp and the technology bias that occurs as a result of image distortion from the colonoscope's fisheye lens, where objects at the center of the display appear magnified and objects at the periphery appear small and warped [13], make it increasingly difficult to estimate CPS.…”