食道表在癌の深達度診断―X線・内視鏡・超音波内視鏡による

Diagnosis of the Depth of Invasion in Superficial Esophageal Cancer by Roentgenography, Endoscopy and Endoscopic Ultrasonography

要旨　食道表在癌をX線・内視鏡・超音波内視鏡の各々の立場から深達度診断について検討した．①sm癌の肉眼分類では0-Ⅰ型，0-Ⅲ型および混合型が82％を占めた．②m癌の肉眼分類では0-Ⅱbまたは0-Ⅱc型が94％を占めた．0-Ⅱc～Ⅱb型m癌18病変と0-Ⅱc型sm癌（11病変）を対象としたX線・内視鏡所見の分析では，③ep癌とmm微小浸潤癌を1つのグループとみなした場合，他のmm癌との鑑別はある程度可能であった．④0-Ⅱc型sm癌はsm浸潤量が少なくmm癌の所見に類似していたが，⑤X線的には側面像の伸展不良の程度，内視鏡的には癌表面の色調と顆粒状所見に違いが認められた．また超音波内視鏡による深達度診断の現状についても述べた．

　Superficial esophageal cancer was examined by roentgenography, endoscopy and ultrasonographic endoscopy regarding its depth of invasion.

　Eighty-two percent of sm cancers were macrosopically 0-Ⅰ type, 0-Ⅲ type or mixed type. 0-Ⅱc type accounted for 18% of sm cancer and had relatively mild invasion compared with other types. On the other hand, 0-Ⅱc type and 0-Ⅱb type accounted for 94% of m cancer macroscopically. Radiological and endoscopic findings of 0-Ⅱc ～ 0-Ⅱb type superficial cancers were as follows :

　(1) The findings of ep cancer and mm minute invasive cancer were similar each other but they were relatively easily differentiated from other mm cancers.

　(2) Although the findings of 0-Ⅱc type sm cancer were similar to those of 0-Ⅱc mm cancer, there were differences in distensibility on lateral radiograph and characters in the surface color and granularity on endoscopy.

　(3) The depth of invasion in 0-Ⅱc type sm cancer and m cancer seems to pose diagnostic problems in the future.

　Findings on the depth of invasion by endoscopic ultrasonography were as follows :

　(1) Differentiation between ep cancer and mm cancer was virtually impossible.

　(2) Accuracy in diagnosing sm cancer was low (55%), but that for sm cancers excluding 0-Ⅱc type 78%.

　(3) There is diagnostic limitation in the currently used instruments. New development is highly expected in this regard.