3．病理からみた比較深達度診断

Comparative Diagnosis of Depth of Cancer Invasion in the Gastrointestinal Tract

要旨　消化管（食道，胃，大腸）の深達度診断の違いを検討するために，各臓器の構造の違い，癌の組織型の違い，肉眼像の違いを検討した．構造の違い：食道は，上皮が重層扁平上皮で，脈管に富む粘膜固有層の幅が広い．胃は，腺上皮で部位によって異なる上皮を有し加齢とともに変化し，粘膜固有層が狭い．大腸は，単一管状腺管から成る上皮で，粘膜固有層が狭い．癌の組織型と深達度：食道は，扁平上皮癌で，肉眼的に隆起性が多く，深達度が高さによって推定できる．胃は，腺癌で，高分化から低分化までみられ，消化性潰瘍がある点で，他の臓器とは異なった深達度診断が必要である．大腸は，高分化腺癌で，隆起性の場合は腺腫を合併するために深達度診断が困難であるが，表面型の場合は，消化性潰瘍がない点を除いては，胃の分化型とほぼ同様の考えで，形態とpit patternを併用することによって深達度診断が比較的容易である．

　To estimate the diagnostic discrepancy of depth of cancer invasion among gastrointestinal tract organs (esophagus, stomach and colon), we show the characteristic points of normal structure, histological appearance of cancer and macroscopic appearance of cancer in each organ.

　Esophagus: The epithelium is stratified squamous epithelium and the lamina propria with many vessels is wide. Histological type of cancer is squamous carcinoma and macroscopically, many tumors show a protruded lesion, and the depth of cancer invasion is diagnosed by the height of the protrusion. Stomach: The epithelium is glandular epithelium and the lamina propria with scanty vessels is narrow. Peptic ulcer is a characteristic feature of the stomach. Histologically, the cancer is adenocarcinoma with differentiation from well to poor. The histology of this type of cancer and peptic ulcer makes the diagnosis of depth of cancer invasion difficult. Colon: The epithelium is simple columnar epithelium and the lamina propria with scanty vessels is narrow. Histologically, almost all cancers are well to moderately differentiated adenocarcinoma. Macroscopically protruded type cancers contain an adenoma component (carcinoma in adenoma), so diagnosis of depth of cancer invasion is difficult. The macroscopic feature and endoscopic pit pattern diagnostic method makes it possible to diagnose macroscopically flat type cancer that has no adenoma component.

　The endoscopic pit pattern diagnostic method is useful for diagnosis of cancer and depth of cancer in the colon.