Ⅰp・Ⅰsp型早期大腸癌の深達度診断―ピオクタニン染色による拡大内視鏡所見の解析を中心に

A Novel Detection Method of Invasive Colorectal Cancers of Pedunculated and Subpedunculated Types by Means of Magnifying “Chromocolonoscopy” Using Crystal Violet

要旨　拡大内視鏡によるⅠp・Ⅰsp型早期大腸癌の深達度診断指標を明らかにすべく，pit patternの不整さとピオクタニン染色によるpit間部分の染色性（SA pattern）の2つを指標に，組織所見との関係を検討した．フラクタル解析したpit patternの不整さは，腺管構造の複雑さ（p＜0.0001），細胞異型（p＝0.0412）を反映し高異型度癌の診断指標となりえたが，sm浸潤長との直接の相関は認めなかった．一方，SA patternはsm癌浅層の組織所見である表層上皮（p＝0.0001），粘膜内部（p＝0.0004），粘膜筋板（p＝0.0005），desmoplasia（p＝0.0059）の各状態を反映し，さらにsm浸潤度（p＝0.0008）を反映しうる指標であることが示された．

　In order to clarify the method of detacting pedunculated and subpedunculated colorectal cancers infiltrating as far as the submucosa, complexity of pit pattern and staining pattern of the area between pits (SA pattern) were investigated by means of magnifying chromocolonoscopy using crystal violet.

　Complexity of the pit pattern evaluated by means of fractal dimension was investigated from the viewpoint of its correlation with glandular and cellular atypia. SA pattern was also examined from the viewpoint of its correlation with histologic changes accompanied by cancer invasion.

　Close correlation was found between complexity of pit pattern and histologic findings, such as glandular (p＜0.0001) and cellular atypia (p＝0.041) . Close correlation was also found between SA pattern and histologic findings of invasive cancers, such as changes in surface epithelium (p＝0.0001), mucosal layer (p＝0.0004), muscularis mucosae (p＝0.0005), desmoplasia (p＝0.0059) and, moreover, vertical depth of submucosal invasion (p＝0.0008).

　Magnifying endoscopic examination using crystal violet staining proved to be useful not only in diagnosing invasive colorectal cancers but in diagnosing histologic grandular and cellular atypia and, histologic changes of invasive cancers.