胆道癌取扱い規約からみた胆管癌の病理と悪性度

Histological Grading of malignancy of extrahepatic bile duct carcinomas

要旨　胆管癌160症例，162病変の肉眼型と組織学的予後因子（ly，v，pn，n，s，hw，dwとKi－67免疫染色による細胞増殖能）との相関，および癌の細胞異型度とp53蛋白過剰発現について検討した．早期癌（n＝9）では，ly₁が1例11％にみられたのみで，v，pn，nはすべて陰性であった．進行癌（n＝153）では，lyが75％，vが44％，pnが84％，n（n＝137）が40％にみられた．これら組織学的予後因子と肉眼型との間に，相関はなかった．漿膜面癌露出は，全例浸潤型癌でみられた．びまん浸潤型は上部胆管に，その他の肉眼型は中下部に多く，上中下部にまたがる広範囲癌は，浸潤型癌に多かった．乳頭限局型・結節限局型・乳頭浸潤型・結節浸潤型の癌では，びまん浸潤型癌に比べて，癌先進部深達度がmである頻度が高かった．びまん浸潤型では，同深達度がssであることが多く，m癌先進部との差は，肝側で平均13.8mm，十二指腸側で8.3mmであった．Ki－67陽性率は，肉眼型，組織型，浸潤とは特に関係なかったが，細胞異型度と相関し，高・低異型度癌の間で有意差を認めた（p＜0.05）．p53蛋白過剰発現は胆管癌の58.0％（29/50）にみられたが，細胞異型度と組織型と関係なく，予後因子としてよりむしろ診断基準に有用と考えられた．

　We studied the correlation between gross type and histological prognostic factors of extrahepatic bile duct carcinomas and also the correlation between their cytological atypia and p53-protein overexpression, using 162tumors (9early cancers and 153 advanced cancers) in our files concerning the digestive organ. Early carcinomas revealed no lymphatic permeation (+), venous permeation (+), perineural invasion (+) and lymph nodal metastasis (+) except in one case with lymphatic permeation. Contrary to this, advanced carcinomas revealed as high as 75.2% of lymphatic permeation (+), 44.4% of venous permeation (+), 83.7% of perineural invasion (+) and 40.1% lymph nodal metastasis (+). None of these histological prognostic factors were able to be correlated to macroscopic types. Diffusely infiltrating cancers significantly occurred in the superior portion of the extrahepatic bile duct and extended further proximally and distally at the subserosa. The Ki-67 index of proliferation was significantly higher in carcinomas with high-grade atypia than in carcinomas with low-grade atypic. It was found that p53-protein was overexpressed in 58.0% (29/50) of carcinomas regardless of their cytological atypia. The Ki-67 index of proliferation seems to be one of the histological prognostic markers for extrahepatic bile duct cancers, but p53-protein overexpression, though not one of the markers, seems to be a useful tool for a diagnosis of carcinoma.