大腸通常型腺腫，腺癌の拡大内視鏡診断─深達度診断を中心に

Magnifying Endoscopic Diagnosis for Standard Colorectal Adenoma and Carcinoma

要旨●拡大内視鏡観察による大腸腫瘍の深達度診断について，pit patternとNBI所見を中心に解説した．pit pattern分類は確立しているが，V_I型高度不整の診断基準が正確には定義されていないことを説明した．NBIに関しては，NICE分類，JNET分類などの新分類の内容を紹介した．NICE分類およびJNET分類共に“vessel pattern”のみでなく“surface pattern”を含めての総合評価が基本である．JNET分類Type 2B以外の病変はおおむねこれだけで十分深達度診断可能であるが，Type 2Bは診断精度がやや低いので色素を用いたpit pattern診断を追加すべきである．また，他のTypeでも診断に迷う場合やlow confidenceの場合は色素を用いたpit pattern診断を追加すべきである．

　This report reviewed the invasion depth for the diagnosis of colorectal neoplasia using magnifying colonoscopy and focused on pit pattern and NBI. Despite the establishment of the pit pattern classification（Kudo & Tsuruta）, the diagnostic criteria for severe irregular V_I type pit pattern remains unclear. As for NBI, we introduced the NICE and JNET classification. In these classifications, both vessel and surface patterns are essential for application. Except the JNET classification type 2B, each JNET category is sufficient for characterizing colorectal neoplasia. Furthermore, the diagnostic ability of type 2B is relatively low compared with that of other categories. Based on this fact, pit pattern diagnosis with chromoagents, such as indigo carmine or crystal violet, should be added to cases showing type 2B or in categories with a low confidence in the use of JNET classification.