最大径10mm以下の大腸sm massive以深癌の内視鏡診断

Endoscopic Diagnosis of the Depth of Invasion of Colorectal Carcinoma Smaller Than 10 mm in Size with Massive Submucosal Invasion

要旨　最大径10mm以下のsm massive以深(400μm以上)に浸潤した大腸癌の通常内視鏡による深達度診断能について検討した．sm400μm以深癌の指標として，隆起型で緊満感，表面不整・粗糙所見，表面型で表面粗糙，陥凹の存在・深さ・形状(類円形)が有用であった．sm 1,500μm以深癌の指標としては，隆起型で上記所見に加えてひだ集中所見，表面型で陥凹の存在・深さ・形状(類円形)所見が有用であった．また，径11mm以上の病変との比較では，sm massive以深に浸潤した隆起型癌は大きさ別に検討しても内視鏡像に有意差は認めなかったが，表面型癌では，径10mm以下のsm massive以深癌と比較して径11～30mmのsm massive以深癌で壁硬化像，表面凹凸不整，粗糙，びらん，陥凹内白苔の所見を有意に高率に認めた．径10mm以下の病変のうち，通常内視鏡観察施行後に拡大観察を施行しⅤ型pit patternを呈した病変の深達度診断能について検討したが，通常および拡大観察の診断能に有意差は認めなかった．

　We assessed endoscopic findings for diagnosis of the depth of invasion in colorectal carcinoma smaller than 10 mm in size with submucosal (sm) massive invasion. Expansiveness, irregular surface, and roughness were useful indicators of sm invasion deeper than 400μm in a polypoid type lesion. Roughness and depressed area (deep and roundish) were useful indicators of sm invasion deeper than 400μm in a superficial type lesion. Expansiveness, irregular surface, roughness, and fold convergence were useful indicators of sm invasion deeper than 1,500μm in a polypoid type lesion. A depressed area (deep and roundish) was a useful indicator of sm invasion deeper than 1,500μm in a superficial type lesion.

　There was no significant difference in the endoscopic findings of sm massive invasion in polypoid type lesions between smaller than 10 mm and larger than 11 mm in size. However, wall rigidity, irregular surface, roughness and surface destruction were useful indicators in a superficial type lesion larger than 11 mm in size.

　There was no significant difference in diagnosis of the depth of invasion between ordinary and magnifying colonoscopic findings in the lesions with the V type pit pattern smaller than 10 mm in size.