Fig. 1

Fluorescence imaging with EP-HMRG of the four representative cases (cases #1, #15, #17, and #18). a Endoscopic imaging with white light before endoscopic submucosal dissection (ESD). b Endoscopic imaging with white light after ESD. The squamocolumnar junction (SCJ) is shown as a green line (case #1). c Fluorescence imaging after EP-HMRG spraying. The ROI of the tumor is the solid circle, while the ROI of non-tumor is the dotted circle. d Resected specimen mapping for the tumor region. The adenocarcinoma is shown as red lines. e Time course of the fluorescence intensity of the tumor lesion and non-tumor region after spraying EP-HMRG. f Hematoxylin and eosin staining and immunohistochemical examination investigating DPP-IV expression in the tumor and non-tumor regions. g Immunohistochemical examination investigating DPP-IV expression in the tumor and non-tumor regions. Scale bars of b–d, 5 mm. Scale bars of f and g, 200 μm