Barrett食道の考え方―最近の進歩を踏まえて

The Recent Advances and Concept of Barrett's Esophagus

要旨　Barrett食道の診断にはesophagogastric junction（EGJ）の同定が重要であるが，それは困難である．それを解決する方法としては柵状血管の下端を認識することが現時点では最も妥当と考えられる．一方Barrett食道は食道の扁平上皮が円柱上皮で置換された状態であるが，その組織学的特徴は噴門腺粘膜，ならびにそれに杯細胞化生を伴った上皮で基本的には胃の形質を有している．またその発生に関してはいまだ明らかになっていないが，最近になり扁平上皮からの異分化，食道噴門腺の露出，multilayered epitheliumからの分化などが示唆されている．

　Although essential for diagnosis of Barrett's esophagus, identification of the esophagogastric junction (EGJ) is extremely difficult. Currently, the best approach to identify EGJ is to determine the lower end of the longitudinal vessels. Barrett's esophagus is a condition in which the normal squamous epithelium of the esophagus is replaced by a columnar epithelium, which exhibits the histological characteristics of the cardiac gland mucosa associated with goblet cell metaplasia and which thus represents the characteristics of the gastric epithelium. The pathogenesis of this disease is still poorly understood, but several mechanisms, such as disdifferentiation from the squamous epithelium, exposure of the esophageal cardiac glands, and differentiation from the multilayered epithelium, have been suggested.

　1) Division of Clinical Laboratory, National Cancer Center Hospital, Tokyo