早期胆道癌の定義と診断―臨床の立場から

Definition and Diagnosis of Early Cancer of the Biliary Tract: From the clinical viewpoint

　文章というものは，何度書いても，いつも“序破急”の序に苦労する．ペンを握ることは，いつもながら，大変苦しい作業を強いられることになるのであるが，袋小路から抜け出すための，ささやかな模索を試みることは，大変生き甲斐があると考えている．そのため，暇がない，忙し過ぎると愚痴をこぼしながらも，書くことを否めないのである．

　ごく最近読んだ伊東俊太郎著「科学と現実」（中央公論社）には，“同一の長さの時間も年をとるに従って短く感ぜられる”というウィリアム・ジェイムスが指摘した事実は，ジャネーの法則“或る人の生涯の，或る時期における一定時間の心理的長さは，その人のその時までの生涯の長さの逆数に比例する”として表現されているそうである．

　We have attempted to define and diagnose accordingly early cancer of the biliary tract by analyzing what we believe to be cases of early cancer of the biliary tract from a clinical standpoint. We have based our attempt on both reported cases and those experienced by us after we divided biliary tract cancer into cancer of the bile duct and gallbladder cancer.

　Early cancer of the bile duct is defined as such when the cancer invasion is limited within the submucosal connective tissue and the cancer itself has developed in the bile duct without any metastasis to the adjacent organs or lymph nodes. Cancer of the bile duct invading the muscularis propriae is treated as of another category to be placed, in the future, in its proper place of relatively early cancer of the bile duct. In order to detect early cancer of the bile duct we should not neglect the indefinite subjective complaints referable to those of the biliary tract and the study of the liver function test and any abnormality in the enzymes of the biliary tract, of course, in addition to US, ERCP, PTC, etc.

　Early cancer of the gallbladder is defined as cancer localized within the gallbladder whose cancer invasion is confined within the mucosa or muscle layer. At present, only a small number of early cancers of the gallbladder have been diagnosed as such before the operation. We should try and find protruded lesions within the gallbladder by US in patients with indefinite subjective complaints. For qualitative diagnosis ERCP is most suitable in such cases.