Decreased numbers of vascular networks and irregular vessels on narrow-band imaging are useful findings for distinguishing intestinal lymphoma from lymphoid hyperplasia

Background No method for sufficiently making the differential diagnosis of intestinal lymphoma resembling lymphoid hyperplasia (LH) on endoscopy has yet been established. Objective The aim of this study was to evaluate the usefulness of narrow-band imaging (NBI) in diagnosing intestinal lymphoma. Design Prospective study. Setting Single-center study. Patients Sixty-one patients with primary or systemic lymphoma were enrolled in this study. Interventions The terminal ileum and entire colon were observed by using conventional endoscopy. NBI was subsequently performed when small polypoid lesions were detected. A decrease in the number of vascular networks (DVNs) and the presence of irregular vessels on the surface of the epithelia were defined as characteristic findings of intestinal lymphoma. The diagnostic accuracy of these 2 findings in distinguishing intestinal lymphoma from LH was examined. Main Outcome Measurements The ability to use NBI to distinguish intestinal lymphoma from LH. Results Two hundred ninety-four small polypoid lesions, including 59 lymphomas and 235 LH lesions, were detected. The rates of detecting DVNs and the presence of irregular vessels were significantly higher in the lymphoma samples (81.4% and 62.7%) than in the LH samples (25.5% and 4.7%). Based on these findings, the diagnostic accuracy, sensitivity, specificity, and positive and negative predictive values for differentiating intestinal lymphoma from LH were 88.8%, 62.7%, 95.3%, 77.1%, and 91.1%, respectively, which are significantly higher than those of conventional endoscopy. Limitations Single-center study. Conclusion DVNs and the presence of irregular vessels on NBI are thus considered to be useful findings for differentiating intestinal lymphoma from benign LH.