食道上皮内腫瘍の臨床病理学的特徴

Clinicopathological Characteristics of Esophageal Squamous Intraepithelial Neoplasia

要旨●食道上皮内腫瘍は内視鏡的に，①癌の近傍にあり，ヨード染色で淡染を示す病変，②白色光像，NBI像で発見可能だが，ヨード染色で淡〜正染を示す病変，③内視鏡像で発見困難かつヨード染色で正染を示す病変の3種類に大別される．上皮内腫瘍の大部分は①であるが，臨床病理学的に問題となるのは，内視鏡的に発見されるが生検で癌とまで病理診断できない②の病変である．上皮内腫瘍の病理診断には，腫瘍性，良悪性の鑑別が重要であり，具体的には，領域性，細胞異型，細胞の配列に注目して診断する．本稿では，病理診断する際の注目すべき種々の所見を示し，具体的な診断過程を提示した．

　Esophageal SIN（squamous intraepithelial neoplasia）is endoscopically classified into three types：（1） SIN that exists adjacent to a squamous cell carcinoma showing weak iodine staining ; （2） SIN that can be detected on white-light and narrow-band imaging with positive iodine staining ; and（3） SIN that is difficult to detect on endoscopic images with positive iodine staining. Most SINs are the former type ; however, the first type has clinical issues because it is detected endoscopically but cannot be pathologically diagnosed as SIN using biopsy. Furthermore, for the pathological diagnosis of SIN, distinguishing between neoplastic tumors from benign/malignant tumors is important. Specifically, diagnosis should be made by focusing on regionality, cell atypia, and cell arrangement. This study provided various notable findings for the pathological diagnosis of SIN.