大腸腺腫症における超微小病変の拡大pit pattern

Magnified Pit Pattern of the Ultramicro-lesion of the Adenomatous Polyposis Coli

要旨　経験したAPC5症例のうち，3症例に対し，拡大電子スコープを用いて多発する腫瘍性病変のpit patternによる診断を行った．観察しえた200個以上の腫瘍性病変は主として，ⅢL型pitで構成されており，数腺管のⅡb様，またはⅡa＋dep病変もamorphismのないⅢL型pitで構成されていた．APC5症例の中で，sm癌は，表面陥凹型由来と思われ，進行癌も小型のⅡa＋Ⅱc様癌であった．APCで進行癌に至る経路は，陥凹型のde novo発生も考慮する必要がある．一般臨床で発見されたⅡa＋dep 1,050病変でsm癌が存在せず，点墨下経過観察例でもほとんど変化しない事実からも，APCで多発するⅡa＋depは多くはlong standingな経過をたどるだろうと考えられた．実際，治療した中でⅡa＋depまたはⅡaで早期癌は存在しなかった．

　We evaluated pit pattern of the multiple lesion of the three out of five cases of APC which we experienced by the magnifying electric endoscopic examination. More than 200 neoplastic lesions of APC were examined, most of them were composed of type Ⅲ_L pits; even the type Ⅱb-like lesion being made of several ducts and the type Ⅱa ＋ dep lesion were composed of type Ⅲ_L pits without amorphism. In the group of five cases of APC, sm cancer was thought to be derived from the surface depressed type, and advanced cancer was a small type Ⅱa＋Ⅱc-like cancer. The mechanism of transformation of APC to advanced cancer should include de novo genesis of the depressed type. No sm cancer was found in the 1,050 type Ⅱa＋dep lesions in routine examinations, and there was almost no change in shape of the type Ⅱa＋dep lesions which had been followed with the marks by indian ink. Therefore, most of the type Ⅱa＋dep lesions which were common in APC may not change in a short period. Actually, we did not find early cancer in the type Ⅱa＋dep or Ⅱa lesions.