Endoscopic findings using narrow-band imaging to distinguish between basal cell hyperplasia and carcinoma of the pharynx

Narrow-band imaging (NBI) has been reported to be useful for detecting superficial-type esophageal or head and neck squamous cell carcinoma (SCC), and in the present study we have used NBI to detect non-carcinomatous lesions, such as basal cell hyperplasia (BCH) accompanied by microvascular irregularities; these non-carcinomatous lesions were pathologically discriminated from squamous cell carcinoma of the pharynx. The aim of the present study was to clarify the endoscopic characteristics of BCH that contribute to the discrimination of superficial-type head and neck SCC (HNSCC). We examined the key endoscopic findings capable of distinguishing BCH from SCC using 26 BCH and 37 superficial-type SCC of the pharynx that had been pathologically diagnosed at our institution between January 2008 and July 2012. The clinicopathological factors were also compared. The size of the BCH lesions was significantly smaller (P < 0.001), and their intervascular transparency was more clearly observed (P < 0.001). Intra-epithelial papillary capillary loop (IPCL) shapes were less variable and monotonous (P < 0.001), and the distribution of the IPCL was more regular with an interval comparable to that of SCC (P < 0.001), although no significant differences in the sharpness of the lesion border, dilatation of IPCL and tortuosity of the IPCL were seen between the BCH and SCC lesions. This study revealed that BCH was an independent entity in terms of not only pathological findings, but also endoscopic findings observed using NBI, such as the regular distribution of IPCL and the preserved intervascular transparency.