Endoscopic prediction of advanced histology in diminutive and small colorectal polyps

Most polyps detected during colonoscopies are diminutive or small, and they rarely have advanced histology. Real-time prediction of advanced histology would help clinicians to assess the need for pathological evaluation. Here, we investigated endoscopic predictors of advanced histology in diminutive and small polyps.

Consecutive patients with adenomatous polyps (<10 mm) removed endoscopically from January 2013 to December 2014 at a single tertiary cancer center were eligible for inclusion. Two endoscopists reviewed all endoscopic images to identify significant findings associated with advanced histology using multivariate models. The sensitivity, specificity, and negative predictive value of the identified endoscopic predictors for advanced histology were calculated.

Of 6170 polyps (4746 diminutive) removed from 2611 patients, 320 (5.2%) showed advanced histology, including five submucosal invasive cancers. In multivariate analysis, advanced histology was significantly associated with the following: loss of lobulation (odds ratio [OR] 61.7; 95% confidence interval [95% CI]: 19.1-199.0); heterogeneity in mucosal patterns (OR 29.0; 95% CI: 14.6-57.3); non-polypoid growth (OR 15.7; 95% CI: 4.4-55.5); white spots (OR 13.5; 95% CI: 7.8-23.5); and surface redness (OR 6.6; 95% CI: 3.0-14.5); and irregular capillary pattern (OR 4.8; 95% CI: 2.5-9.1). These significant predictors successfully predicted all submucosal invasive cancers as advanced histology. The sensitivity, specificity, and negative predictive values were 37.2%, 97.8%, and 96.6%.

We identified six endoscopic predictors for advanced histology in diminutive or small colon polyps. Diminutive and small polyps lacking these predictors would not be considered to have advanced histology.