M Min, TH Dong, Y Liu, YL Bi, CY Ma - Chinese medical journal, 2019 

Background: Gastric intestinal metaplasia (GIM) is generally considered to be the main mucosal background for the development of gastric adenocarcinomas. Using linked color imaging (LCI), we noticed that the color pattern in areas of GIM was purple mixed with white on the epithelium with signs of mist that were detected by the non-magnifying LCI observation. We have termed this endoscopic finding “Purple in Mist” (PIM). The aim of this study was to investigate whether PIM could be a useful optical sign for predicting GIM.

Methods: We prospectively evaluated consecutive patients undergoing endoscopy for various indications. The endoscopist used the LCI system to carefully observe the gastric antrum, body and angulus. When a PIM was identified in the surface layer, targeted biopsies were subsequently taken from this part. If the suspected area had no PIM on the surface, targeted biopsies were also taken.

Results: Sixty-three consecutive patients were included in this study. The prevalence of intestinal metaplasia (IM) was 29/63 (46%). In PIM-positive patients, the prevalence of IM was 23/26 (89%). Of these patients, 146 biopsy specimens were included in this study. For the diagnosis of IM, compared to histological assessment, the LCI finding had an accuracy of 91.1% (95%CI: 86.5%–95.7%), a sensitivity of 89.8% (95%CI: 81.3%–98.3%), a specificity of 91.8% (95%CI: 86.3%–97.2%), a positive predictive value of 84.6% (95%CI: 74.8%–94.4%), and a negative predictive value of 94.7% (95%CI: 90.1%–99.2%).

Conclusions: A positive PIM finding in a suspicious lesion on LCI would complement LCI diagnosis of possible IM because of the positive predictive value of PIM. PIM could be a novel endoscopic marker for IM.