Squamous metaplasia without atypia.

An 89-year-old man presented with a 1-month history of anemia. The results of a physical examination were normal. Diagnostic gastrointestinal endoscopy showed advanced atrophic gastritis, multiple ulcer scars, and a whitish, slightly depressed lesion 15mm in size in the lesser curvature of the antrum (●" Fig.1). Squamous metaplasia without atypia was diagnosed based on examination of the specimen obtained from the depressed lesion (●" Fig.2). On narrow-band imaging (NBI) of the same site, dot-like vascular structures were observed (●" Fig.3). NBI magnification indicated the presence of intra-epithelial papillary capillary loop (IPCL)-like vascular structures, reflecting the squamous epithelium, which is usually observed in pharyngeal and esophageal areas, not the stomach (●" Fig.4). In previous reports, the endoscopic appearance of gastric squamous metaplasia has been described as that of whitish lesions [1,2]. Although the pathogenesis of the patient’s squamous metaplasia was unclear, it is well documented that atrophic mucosa and ulcerative lesions are caused by chronic inflammation in the stomach. It was also considered relevant that multipotent stem cells and squamous metaplasia appear in the stomach during the process of ulcer healing [2,3]. We have reported this case because squamous metaplasia without atypia is rarely seen in the stomach. Moreover, the findings obtained by magnified endoscopy combined with NBI have not been reported for squamous metaplasia to date.