Proportion of esophageal keratinized area ≥ 30% reduces accuracy of preoperative endoscopic evaluation in early esophageal squamous cell carcinoma

Figure 1 Endoscopic appearance of early esophageal squamous cell carcinomas and esophageal keratosis. A: Esophageal keratosis (white arrows) on the surface of normal esophageal epithelium under white light endoscopy (WLE); B: Nonepithelial keratosis in early esophageal squamous cell carcinoma (ESCC) (orange arrows) under WLE; C: Nonepithelial keratosis early ESCC (orange arrows) under narrow-band imaging with magnifying endoscopy (NBI-ME) (orange arrows); D: Proportion of esophageal keratinized (yellow arrows) area < 30% in early ESCC (orange arrows) under WLE; spontaneous bleeding was visible (black arrows) in the lesion area; E: Proportion of esophageal keratinized (yellow arrows) area < 30% in early ESCC (orange arrows) under low-power NBI-ME; spontaneous bleeding was visible (black arrows) in the lesion area; F: Proportion of esophageal keratinized (yellow arrows) area < 30% in early ESCC (orange arrows) under high-power NBI-ME; spontaneous bleeding was visible (black arrows) in the lesion area; G: Proportion of esophageal keratinized (yellow arrows) area ≥ 30% in early ESCC (orange arrows) under WLE; H: Proportion of esophageal keratinized (yellow arrows) area ≥ 30% in early ESCC (orange arrows) under low-power NBI-ME; I: Proportion of esophageal keratinized (yellow arrows) area ≥ 30% in early ESCC (orange arrows) under high-power NBI-ME.