Concordance between nice classification and histopathology in colonic polyps: a tertiary center experience.

Background: Narrow-Band imaging International Colorectal Endoscopic (NICE) could reduce histopathology study requirements in colorectal polyp evaluation. Local and regional studies are required to validate its utility.

Objectives: To evaluate concordance between NICE classification and histopathology.

Design: Prospective analytic study performed in the Hospital Universitario San Ignacio, Bogotá (Colombia) between 2021 and 2022.

Methods: Concordance between NICE I, II and III classification and histopathology [Hyperplastic Polyp (HP), adenoma and deep submucosal invasive cancer (DSIC)] was evaluated using weighted kappa. Diagnostic performance was evaluated for NICE I-II versus NICE III for DSIC versus adenoma/HP. A subgroup analysis was performed for polyps ⩾10 mm and those located in the rectum, sigmoid, and left colon.

Results: A total of 238 polyps from 135 patients were evaluated. Median age 67 years (IQR 58.5-74.5), 54.4% males. 23 (17.1%) had ⩾3 polyps. Of polyps, 52.1% were located on rectum, sigmoid and left colon. A total of 182 (76.5%) were <10 mm. NICE and histopathology evidenced a fair-moderate concordance (quadratic weighted kappa 0.36, linear weighted kappa 0.43). NICE classification (NICE I-II versus III) compared to histopathology (DSIC versus adenoma/HP) evidenced a sensitivity of 90.9% and specificity of 99.1%. For DSIC diagnosis specificity was ⩾95% on polyps ⩾10 mm and those left sided located.

Conclusion: NICE and histopathology concordance is suboptimal. However, NICE III for DSIC diagnosis evidence good specificity. Therefore, NICE III polyps require a prompt histopathological evaluation and follow-up. Good operative characteristics stand in polyps ⩾10 mm and left sided located. NBI formal training is recommended in gastroenterology units in Latin America.