Magnifying colonoscopy:: interobserver agreement in the assessment of colonic pit patterns and its correlation with histopathological findings

Background and study aims Magnifying colonoscopy (MC) is recognized as an aid to the differential diagnosis between neoplastic and nonneoplastic lesions. This study evaluated interobserver agreement of experienced endoscopists in the assessment of colonic pit patterns through the Kudo's classification and correlated morphological aspects with histopathological findings. Materials and methods A total of 213 magnification chromoendoscopic pictures of colonic lesions were collected from 161 consecutive patients and presented to three independent observers who expressed opinion about predominant pit pattern. All lesions were excised and sent for histopathological study. Results Kappa statistics showed that the general agreement index with respect to the aspects of the pits was good among the three observers (0.561). Regarding prediction of histopathology according to the pit pattern diagnosis, overall accuracy was 84%, sensitivity was 91.4%, specificity was 67.2%, positive predictive value was 86.6%, and negative predictive value was 79.3%. Conclusion Although the interobserver reproducibility of the colonic pit pattern is good for experienced endoscopists, MC must not be used to replace the histopathological analysis, since it does not differentiate with the necessary safety neoplastic from nonneoplastic lesions.