浸潤形式からみたPG type隆起型早期大腸癌—0-Is，Isp病変の特徴について

Colorectal Submucosal Cancer of Protruded and Polypoid Growth Type from the Viewpoint of Infiltration Type（on the Features of 0-Is, Isp Lesions）

要旨●隆起型早期大腸癌（T1癌）を粘膜筋板残存の程度，粘膜内癌部または推定粘膜内癌部分の有無から浸潤形式を4群に分類し，その臨床・内視鏡・病理学的特徴について検討した．従来，隆起型早期大腸癌の深達度の正診率は表面型早期大腸癌と比較して低いと言われてきたが，今回の検討でも深達度T1の隆起型早期大腸癌の深達度診断の正診率は表面型と比較して低く，特に粘膜内癌部が残存し，表層にDR（desmoplastic reaction）が露出していない病変において低い傾向を認めた．隆起型早期大腸癌の正診率の向上には拡大内視鏡を用いたpit pattern診断のみならず，通常内視鏡所見，特に緊満感に留意した評価も重要である．また必要に応じて超音波内視鏡検査や消化管X線造影検査など，他のmodalityでの検索も積極的に行う必要があると考えられた．

　We investigated the clinical, endoscopic, and pathological features of submucosal colorectal cancer classified into four groups based on the degree of remaining of mucosal muscle plate and the intramucosal or estimated intramucosal carcinoma portion.

　The rate of diagnostic accuracy based on the degree of the depth in the protruded type is low compared to the surface type. In this study, we also confirmed that the diagnostic accuracy rate was lower than that of the surface type, in particular, the lesions remaining in the intramucosal or estimated intramucosal carcinoma portion and the lesions not accompanied by desmoplastic reaction.

　Both pit pattern observations using a magnifying endoscope and ordinary endoscopic observations, such as assessing fullness, are important for improving the diagnostic accuracy rate of protruded-type early colorectal cancer, which determines the diagnosis based on depth. In difficult cases, actively searching for other diagnostic modalities such as ultrasound endoscopy and lower intestinal GU series was necessary.