大腸腫瘍の拡大観察―VI型pit patternの分析および診断に関するコンセンサス―工藤班研究成果を踏まえて

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．その結果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，かつsm癌の指標が明確になった．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 give us a lot of benefits in every aspect. In terms of magnifying endoscopy, when we use the colonic pit pattern, we are able to estimate with a high degree of accuracy the histology of the lesion without taking biopsies from it.

　It was known that there were some subtle differences among the institutions where pit pattern diagnoses were used, so the members of Kudo's group started from 2002 the discussion to difine the pit patterns, especially type V pit pattern.

　The subdividions of the typeV pit pattern were agreed up at the Hakone Pit pattern Symposium, in April, 2004. It was determined that the VN pit pattern exhibited only an area of apparent nonstructure. According to further discussion about the VI pit pattern among several institution, we defined the VI type as constituted by destroyed and badly damage pits as a high grade irregularity.

　With the classification based on the Hakone consensus, lesions, which exhibit a new type VN pit pattern are considered to be sm massive cancers. The hightly irregular VI pit pattern has also become one of the indexes of sm massive cancers.