表層拡大型食道表在癌の内視鏡診断―診断のコツと発育過程への考察

Endoscopic Diagnosis of Extensively Spreaded Type of Superficial Esophageal Cancer

要旨　目立った隆起や陥凹を示さない5cm以上に及ぶ表層拡大型食道癌は，表在癌切除例223例中20例を占め，m癌8例，sm癌12例であった．全例男性で，胸部中部食道を中心に存在し，多発病巣を有するものが40％を占めた．リンパ節転移は35％に認められ，m1～m2 0％，m3～sm1 11.1％，sm2～sm3 66.7％，脈管侵襲は60％に認められ，m1～m2 0％，m3～sm1 55.6％，sm2～sm3 77.8％となり，いずれも表在癌全体と差を認めなかった．予後も原病死は3年後に死亡した1例のみであった．内視鏡観察では食道内腔をよく水洗して観察し，軽い発赤や混濁に注意し，ヨード染色を行う．ヨード染色で初めて認識できるもの，網目状・豹紋状に染色されるものは深達度が浅く，中央部付近に深い部分があるので注意を要する．深達度は一段深目に読んだほうがよい．表層拡大型食道癌の発育伸展過程について検証し，仮説を立てた．

　The extensively Spreaded type of superficial esophageal cancer is defined as almost flat (0-Ⅱ) type cancer without marked elevation or depression and more them 5 cm in length. We encountered 20 cases of such cancers in 223 cases of superficial esophageal carcinomas, eight mucosal and 12 submucosal cancers. All cases were male, chiefly located in the middle of the thoracic esophagus, and 40% of them had multiple lesions. Lymph node metastasis was recognized, in 35% of them, m1～m2 0%, m3～sm1 11.1%, and sm2～sm3 66.7%. Lymph vessel invasion was also recognized in 60% of them, m1～m2 20%, m3～sm1 55.6% and sm2～sm3 77.8%. These findings are almost the same as those of all superficial cancers. Prognosis of these cases was relatively good and death occurred after three years because of esophageal cancer in only one case.

　As for endoscopic examination, it is useful for washing up mucus from the surface of esophageal mucosa, picking up reddish flecks and locating the turbid area, and useful for iodine staining. The lesions recogniged only with iodine staining or observed as an unstained area with brown spotty flecks were invaded in shallow layer of mucosa (m1). Usually, the deepest point exists at the center of the lesion. The depth of invasion should be diagnosed as one layer deeper than it seems.

　The growth and progress of extensively spreaded type of superficial esophageal cancer was investigated and a hypothesis about it was formulated.