0%), and mainly found on the right anterior wall (from 0 o’clock to 3 o’clock) of the esophagus (64.0%) (Fig. 5). There were no statistically significant differences in the grade of RE, type of gastric mucosal atrophy, check details and the presence or absence of hiatus hernia between cases of RE on the ridge of mucosal folds or in the valley between folds (Table 2). Although BE is an emerging health problem worldwide, it is also

plagued by controversy regarding its endoscopic diagnosis. A major problem is the significant interobserver variability, partly because of the lack of a universally accepted definition and grading system of SSBE.10,11 To improve the diagnostic concordance in SSBE endoscopically, we focused on the squamous islands and the specific position of columnar epithelium in relation to mucosal folds. Narrow band imaging is a recent optical technique that enhances the diagnostic capability

of endoscopic examination by characterizing tissues using narrow-bandwidth filters in a video system.13,14 Although chromoendoscopy with iodine solution is the gold standard technique for the diagnosis of squamous cell carcinoma of the esophagus,25,26 iodine solution can lead to a transient dysphagia related to esophagospasm, and cause nausea, epigastric discomfort, and allergic reactions.27,28 In the present study, NBI could detect squamous islands in 71 Tofacitinib clinical trial (94.7%) of 75 SSBE cases in which squamous islands were found by iodine chromoendoscopy. WL endoscopy detected only 48 (64%) of the 75 positive cases. Takubo et al. recently reported that the esophageal gland proper, a marker of esophageal mucosa, was found in

squamous islands of columnar epithelium, which suggested the value of squamous islands as a marker of BE.29 Although squamous islands are not reliably recognized by endoscopy with image-enhanced techniques in all cases of SSBE, a diagnosis of SSBE can be made when squamous islands are endoscopically evident in columnar mucosa at locations distant from the squamocolumnar junction. Although the number of identified squamous islands was lower with NBI than with iodine chromoendoscopy in the present study, endoscopic observation using NBI can be recommended as a modality for diagnosing BE because of its 95% detectability of columnar Histidine ammonia-lyase epithelium with squamous islands. Barrett’s esophagus has been generally accepted as a complication of chronic and severe GERD. We have consistently demonstrated that both mucosal breaks and tongue-like SSBE are predominantly found in the right anterior wall of the esophagus.16,17 These findings have been confirmed by other groups.30,31 The asymmetrical lower esophageal sphincter pressure may not effectively prevent gastroesophageal reflux on this side.19 Investigating more precisely the location of tongue-like SSBE and mucosal breaks was the aim of the present study and we found that both are mainly found on the ridges of mucosal folds on the right anterior wall of the esophagus.