3. 箱根コンセンサス・工藤班会議の総括―VI pit patternの分析および診断に関するコンセンサス

The Subdivision of the Type V Pit Pattern―The Results of 4 years' Research in Kudo's Pit Pattern Conference

要旨　2002年からの厚生労働省がん研究助成金「大腸癌腫瘍性病変における腺口構造の診断学的意義の解明に関する研究」班（工藤班）を通じて，大腸癌のV型pit patternは概念の統一化と細分化がなされた．2004年，明らかな無構造領域を有するpit patternをVN型，不整腺管構造を有するpit patternをVI型とした箱根シンポジウムのコンセンサスが得られた．さらに，pitの内腔狭小，辺縁不整，輪郭不明瞭，stromal areaの染色性の低下・消失，scratch sign等の所見を参考にしてVI型高度不整は"既存のpit patternが破壊，荒廃したもの"と定義された．2001年4月から2006年4月までの当院におけるsm癌114病変のpit patternと粘膜筋板，desmoplastic reaction（DR）の検討によりVN型pit patternは全例sm深部浸潤癌であり，腫瘍表層部のDRを示している所見と考えられた．またVI高度不整の所見である内腔狭小や辺縁不整はsm深部浸潤癌の指標の1つと言える．V型pit pattenの分類により大腸腫瘍の内視鏡診断はよりいっそう簡便になり，大腸pit pattern診断は観察から治療方法が直結した診断学になった．

　The development of new technology in Gastrointestinal endoscopy gives us a lot of benefits in every aspect. In terms of magnifying endoscopy, when we used the colonic pit pattern, we were enabled to estimate the histology of the lesion without taking biopsies from it.

　It is known that there have been some subtle differences among various institutions using pit pattern diagnosis, so we started a discussion in to define definition of the pit pattern, especially in type V pit pattern, in Kudo's group.

　The subdivisions of the type V pit pettern were consolidated at the Hakone Pit pattern Symposium, in April, 2004. It was determined that the VN pit pattern exhibited only the area of apparent nonstructure. According to further discussion about among the several institution the VI pit pattern, we defined the VI type with destroyed and desert pits as a high grade irregularity.

　With the classification based on the Hakone consensus, lesions, which exhibited a new type VN pit pattern were considered to be sm massive cancer. The highly irregular VI pit pattern also became one of the indexes of sm massive cancer.