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J Gastroenterol 2009; 44:103–112 DOI 10.1007/s00535-008-2298-y

Review Squamous intraepithelial neoplasia of the esophagus: past, present, and future
MICHIO SHIMIZU1, KOJI NAGATA1, HIROSHI YAMAGUCHI1, and HIROTO KITA2
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Department of Pathology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka 350-1298, Japan Department of Gastroenterology, Saitama MedicalUniversity International Medical Center, Hidaka, Japan

With regard to the esophagus, the term “squamous dysplasia” has been used in European countries, the United States, and China, while its use is controversial in Japan. Recently, “low-grade intraepithelial neoplasia” and “high-grade intraepithelial neoplasia” have been used as inclusive terms for dysplasia and carcinoma in situ in the WorldHealth Organization classification. Endoscopically, it is often difficult to identify squamous intraepithelial neoplasia by conventional endoscopy, but application of iodine is useful for the diagnosis of such a lesion. In addition, new types of endoscopic techniques, including magnifying endoscopy, narrow-band imaging (NBI), and endocytoscopy are helpful to detect squamous intraepithelial neoplasia.NBI is very useful for identifying the intrapapillary capillary loop pattern. Regarding the pathological criteria of squamous dysplasia and squamous cell carcinoma, the views of Japanese and Western pathologists have differed significantly. Before the term “intraepithelial neoplasia” was introduced, severe dysplasia as diagnosed by Western pathologists was in fact the same as squamous cellcarcinoma in situ or noninvasive carcinoma as diagnosed by Japanese pathologists. This problem has been solved by the introduction of the Vienna classification; however, there are still some issues that need to be resolved. One of them is the presence of basal layer type squamous cell carcinoma in situ, which is often underdiagnosed as lowgrade intraepithelial neoplasia by Western pathologists. Endoscopictreatments such as endoscopic mucosal resection and endoscopic submucosal dissection have recently become possible choices for squamous intraepithelial neoplasia; however, these techniques are not in widespread use in the West. We believe that a consensus meeting between Japanese and Western pathologists as well as endoscopists should be held promptly to reach a common ground for the nomenclature.Received / Accepted: September 5, 2008 Reprint requests to: M. Shimizu

Key words: esophageal squamous intraepithelial neoplasia, squamous cell carcinoma in situ (CIS), endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), narrow-band imaging (NBI)

Introduction Of the esophageal cancers, squamous cell carcinoma is the most common carcinoma in Japan. However, in theUnited States, esophageal squamous cell carcinoma is relatively uncommon, with the incidence of adenocarcinoma being higher and rapidly increasing. Adenocarcinomas of the esophagus usually arise in the setting of Barrett’s esophagus.1,2 Therefore, dysplasia in the esophagus, even in English gastrointestinal textbooks,3,4 usually refers to glandular dysplasia, especially in Barrett’s esophagus, andnot squamous dysplasia. Even when searching for articles on esophageal dysplasia, we found that most papers deal with glandular dysplasia in relation to adenocarcinoma derived from Barrett’s esophagus.5 Thus, squamous dysplasia of the esophagus is very rare in the English literature, and most articles are contributed from China or Japan.6–9 In 2000, the World Health Organization (WHO) classificationintroduced the term “intraepithelial neoplasia” for the esophagus.10 Since then, many articles have been using the term “intraepithelial neoplasia” rather than dysplasia or carcinoma in situ (CIS).11,12 In this review article, we specifically focus on and review squamous dysplasia, not glandular dysplasia. Then, we focus on the squamous intraepithelial neoplasia, including the difference in the...