Background and study aim: Although focal cancer occasionally coexists with gastric hyperplastic polyps, previous studies have reported that white light endoscopy (WLE) and biopsy sampling cannot effectively predict the coexistence of cancer. The aim of this study was to elucidate efficacious predictors for cancer coexistence.
Patients and methods: This retrospective single academic center study analyzed consecutive patients with gastric polyps diagnosed as hyperplastic before endoscopic resection. Using an image catalog of WLE and magnifying endoscopy combined with narrow band imaging (ME-NBI) performed as part of the preresection work-up, three endoscopists independently assessed the coexistence of cancer and the presence of predefined ME-NBI findings in the microvasculature (MV) and fine mucosal structure (FMS).
Results: Twelve of 64 gastric polyps (19%) resected from 51 patients enrolled in the study showed the coexistence of neoplasia. Polyps with coexisting neoplasia were significantly larger than those without (22.6 ± 10.1 vs. 15.5 ± 7.7 mm, respectively). Multivariate analysis of factors significantly associated with the coexistence of neoplasia identified lesion size and three specific endoscopic findings, that is, WLE diagnosis of cancer coexistence, ME-NBI findings of abnormal MV and micrification (size reduction) of the FMS. Combining lesion size (≥20 mm) and ME-NBI findings of FMS micrification had a diagnostic accuracy of 100% sensitivity and 58% specificity for coexisting neoplasia. However, combinations of WLE diagnosis and any other criteria could not achieve a diagnostic sensitivity of 100%.
Conclusion: ME-NBI enhances the prediction of cancer coexistence in gastric hyperplastic polyps, with lesion size (≥20 mm) and FMS micrification the most effective predictive findings.