Endosopic autofluorescence imaging is useful for the differential diagnosis of intestinal lymphomas resembling lymphoid hyperplasia.

Background: A method for the differential diagnosis of intestinal lymphomas resembling lymphoid hyperplasia (LH) by endoscopy remains to be clearly established. Objective: To evaluate the usefulness of autofluorescence imaging (AFI) in diagnosing intestinal lymphoma. Setting: Single-center study. Design: Prospective study. Patients: One hundred forty-three samples obtained from the intestinal tissues of 21 patients with malignant lymphoma were included in the study. Interventions: The terminal ileum and entire colon were observed using conventional endoscopy equipped with AFI. The AFI images were taken by 3 endoscopists and then were evaluated by 3 predominant color intensities; green, magenta, and blended. To quantify the strength of fluorescence captured by AFI, the area of the obtained biopsy specimens on images was manually traced, the signal density of either magenta or green was measured, and then the ratio of the reverse gamma value of green divided by that of magenta was defined as the Fluorescence index (F index). Main Outcome Measurements: The ability to use AFI to distinguish intestinal lymphoma from normal or LH. Results: The cell density is inversely proportional to the F index. The F index of lymphoma was significantly lower than that of normal mucosa or LH. The visual classification of AFI showed the overall accuracy in diagnosing lymphoma was 91.5%, and was well correlated with the F index. Limitations: Single-center study. Conclusions: AFI-embossed lymphoma lesions seemed as magenta and could be discriminated from LH or normal mucosa with a high overall accuracy through perception of the cell density of the lesion. Therefore, AFI is considered to be an effective procedure for determining the accurate stage and appropriate therapy in intestinal lymphoma.