表面型早期癌の併存をみた上行結腸多発大腸癌の1例

Simultaneous Multiple Cancers of the Ascending Colon with Superficial Early Cancer, Report of a Case

要旨　患者は68歳，女性．血便を主訴に当センターを初診した．注腸X線および大腸内視鏡査を施行したところ，上行結腸肝彎曲部に大きさ約20mmのⅡa＋Ⅱc様病変を認めた．立ち上がりは緊満感のある正常粘膜で覆われ，中央部には厚い白苔が付着した深い陥凹を認め，深達度ss以深の進行癌と術前診断した．更にそのすぐ肛門側に大きさ15mmのⅡa病変を認めた．表面は平坦で凹凸不整や明らかな陥凹面を有さず深達度mの早期癌と診断した．また，上行結腸のほぼ中央部に大きさ9mmで表面が顆粒状を呈する可動性良好な隆起性病変を認めた．明らかな浸潤癌の所見はなく腺腫ないしは粘膜内癌と診断した．以上から多発大腸癌の診断で右半結腸切除術を施行した．Ⅱa＋Ⅱc様病変は深達度ssの粘液癌，Ⅱa病変は深達度mの高分化腺癌，上行結腸中央部の病変は，粘液結節を形成し深達度sm₃まで浸潤した中分化腺癌であった．病理組織学的には粘液結節を有する2つの癌と表面型m癌の同時三重多発癌であったが，上行結腸中央部の病変はre-trospectiveな検討でも深達度sm₃の診断は困難であった．癌の深達度診断および発育進展を考えるうえで興味ある症例と思われ報告した．

　The patient was a 68-year-old woman, who visited our Center, complaining of hemorrhagic stool. Barium enema radiograph and endoscopy of the large intestine revealed a lesion, about 20 mm in size and Ⅱa+Ⅱc, in the ascending colon near the liver curvature. The foot of the lesion was solid and covered with normal mucosa, and a deep dent in the center was covered with thick white fur. Preoperative diagnosis was advanced cancer, deeper than ss. Another lesion was found on the rectum side, 15 mm in size and Ⅱa, close to the above lesion. The surface was smooth with no irregularities or any apparent dent, which was diagnosed asearly-stage cancer of m. Moreover, approximately in the middle of the ascending colon, a raised lesion of 9 mm, easily maneuverable, with a granular surface, was observed. There was no sign of invasion, and it was di-agnosed as adenoma or intra-mucoua cancer. Right-harf colectomy was performed, and it was revealed that the Ⅱa+Ⅱc lesion was mucous cancer of ss, the Ⅱa lesion was a well differentiated adenocarcinoma of m, and the lesion in the middle of the ascending colon was a mod-erately differentiated adenocarcinoma of sm3 with formation of mucous nodules. Histopathologically the lesions were simultaneous multiple (triple) cancers, i.e., 2cancers with mucous nodules and one superficial cancer of m. The diagnosis of the lesion in the middle of the ascending colon as sm, i was difficult even in the retrospective examination. The case was thought to be interestng for the morphological diagnosis of cancer and for understanding its growth and progression. We re-port this case in this paper.