Clinical impact of narrow-band imaging magnifying endoscopy for 'basal layer type squamous cell carcinoma' in the esophagus.

A 61-year-old man had received endoscopic submucosal dissection (ESD) for early gastric cancer twice. Then he had undergone annual control esophagogastroduodenoscopy using narrow-band imaging (NBI) magnifying endoscope. At the esophagogastroduodenoscopy, we were not able to detect any significant finding in the esophagus by conventional endoscopy. Switching to NBI mode, a brownish area was showed in the middle esophagus. The lesion showing the brownish area was predicted to be mucosal squamous cell carcinoma (SCC) as a result of assessment of morphologic change of intraepithelial papillary capillary loop under magnifying NBI observation. Lugol chromoendoscopy displayed the lesion as unstained area corresponding to the brownish area visualized by NBI. The ESD was performed for the lesion. Histology from ESD specimen showed SCC with minimal invasion to lamina propria at multifocal sites. The SCC was surrounded by low-grade intraepithelial neoplasia. Most of the SCC showed a high degree of cytological and architectural atypia confined to the lower half of the epithelium. The type of SCC was called as 'basal layer type SCC' mainly by Japanese pathologists. We suggest that magnifying NBI endoscopy can be useful for detecting and diagnosing 'basal layer type SCC'.