大腸腫瘍性病変の通常内視鏡診断はどこまで病理診断に迫れるか

Diagnostic Ability of Conventional Endoscopy in Colorectal Neoplasms

要旨　通常内視鏡による大腸腫瘍性病変の異型度および深達度診断能をⅠs型とⅡ型の腺腫と早期癌を対象にして検討した．対象を，表面陥凹（Ⅱc）の有無により，Ⅰs型，Ⅰs＋Ⅱa型，Ⅱa型を表面陥凹（－）型，Ⅰs＋Ⅱc型，Ⅱa＋Ⅱc型，Ⅱc＋Ⅱa型を表面陥凹（＋）型に分類した．組織診断は軽度・中等度異型腺腫をA群，高度異型腺腫とm，sm₁癌をB群，sm_2,3癌をC群に分類した．結果，通常内視鏡で撮影された写真の見直しによる推定組織診断の正診率は，表面陥凹（－）型；A群94％，B群77％，C群92％，表面陥凹（＋）型；A群96％，B群92％，C群100％であった．

　Diagnostic ability of the grade of dysphasia and depth of invasion were investigated in a retrospective study using the endoscopic picture of conventional endoscopy. The elevated sessile type (Ⅰs) and superficial type (Ⅱ) of adenomas and early cancers were included in this study. The lesions were classified as being with or without central depression. Therefore, Ⅰs, Ⅰs ＋ Ⅱa, Ⅱa type lesions were classified into a central depression (－) group and Ⅰs ＋ Ⅱc, Ⅱa ＋ Ⅱc, Ⅱc ＋ Ⅱa type were classified into a central depression (＋) group. Histopathologically, mild or moderate dysplasia were classified into group A, severe dysplasia, intramucosal cancer, or sm₁ cancer were classified into group B, and sm₂ or sm₃ cancer were classified into group C.

　The results were as follows. The rate of correct diagnosis in the central depression (－) group was 94％ (97/103 lesions) in the histopathologic group A, 77％ (37/48 lesions) in group B, and 92％ (11/12 lesions) in group C. And the rate in the central depression (＋) group was 96％ (51/53 lesions) in group A, 92％ (12/13 lesions) in group B, and 100％ (22/22 lesions) in group C.