Value of narrow band imaging endoscopy in early mucosal head and neck cancer

Background. The purpose of this study was to show the investigated prevalence rate of brownish spots of early cancer under narrow band imaging (NBI) in different sites/types of the epithelium. Methods. In all, 125 adults with early mucosal cancer underwent NBI examination. Four types of epithelium were categorized: keratinized thick stratified squamous (type 1), nonkeratinized thin (type 2a) or very thick (type 2b) stratified squamous, and pseudo-stratified ciliated columnar epithelium (type 3). Results. The prevalence rate of brownish spots in early cancer of the nasopharynx, oral cavity, oropharynx, hypopharynx, and epiglottis were 11.1%, 15.9%, 21.4%, 100%, and 100%, respectively. Type 2a epithelium (odds ratio [OR], 76.45; 95% confidence interval [CI], 9.26-631.14) was a significant predictive factor for the brownish spots. Conclusion. The brownish spots have higher reliability for screening in early cancer of the mouth floor, hypopharynx, and epiglottis, but not in other mucosal sites. Mucosal sites with type 2a epithelium have a higher tendency of demonstrating brownish spots.