2）通常内視鏡による診断

Diagnosis of Colorectal Lesions Using Conventional Endoscopy

要旨　通常内視鏡観察において大腸病変を発見した際には，より多くの所見や情報を得るためにインジゴカルミン撒布を行うことが望まれる．まず質診断に関し，腫瘍・非腫瘍の鑑別には病変の色調や表面性状を，腺腫・癌の鑑別に関しては陥凹や二段隆起，色調不均一などの所見に注目して診断を行う．診断が困難な場合には，NBIやpit pattern観察など，他の検査手段を用いて診断を進める．癌が疑われる場合の深達度診断においては，病変表面の性状や病変周囲正常粘膜の所見に着目して診断を行う．しかし，隆起型SM癌をはじめ，深達度診断の確定を迷う病変では，NBIやpit pattern観察などを用いて，より確実な診断を行うことが望まれる．

　We assessed the clinical usefulness of conventional endoscopy for diagnosis of colorectal lesions. Observation of the color and shape of the lesions is useful for differential diagnosis of neoplastic or non-neoplastic lesions. For the differential diagnosis of adenoma or carcinoma, observation of the presence of depression, nodule on nodule and heterogeneity of color is useful. For differential diagnosis of M to SM slight cancer or SM massive cancer, observation of the presence of remarkable depression, submucosal tumor like appearance at the edge of a polypoid lesion, or observation of expansive appearance and poor extension at the circumference of the lesion is useful. Overall accuracy for the differential diagnosis of M to SM slight cancer or SM massive cancer using conventional endoscopy is 77.6%. Conventional endoscopy is useful for diagnosis of colorectal lesions.