術前に診断しえた10×8mmの大腸pm癌の1例

Small Colonic Cancer Invading the Muscularis Propriae, Report of a Case

要旨　患者は65歳，女性．主訴は腹痛．入院中の注腸および内視鏡検査によって，小さなS状結腸癌が発見された．注腸X線検査では中心部にバリウム斑を伴う類円形の陰影欠損を，内視鏡検査では浅い陥凹を伴う扁平隆起を認めた．超音波内視鏡では壁深達度PM′と診断した．病理学的には，10×8mmのⅡa＋Ⅱc様病変（癌のみでは径5mm）で，深達度pmの高分化腺癌であった．腺腫の共存はなかった．脈管侵襲，リンパ節転移は認められなかった．免疫組織学的には，CEAおよびCA 19-9は腫瘍全体に陽性反応を示し，CA 15-3は主に腫瘍浸潤部（先進部）で陽性反応を示した．

　A 65-year-old woman was admitted for abdominal pain. Barium enema and endoscopic examinations revealed a small, flat-elevated lesion of the sigmoid colon with a central shallow ulceration. Histological diagnosis of the lesion was well differentiated adenocarcinoma. Endoscopic ultrasonographic examination (EUS) showed the small lesion invading the muscularis propriae. Sigmoidectomy was performed.

　Macroscopic examination showed a Ⅱa＋Ⅱc-like lesion, 10×8 mm in size. Microscopically, well (partially moderately) differentiated adenocarcinoma invading the muscularis propriae. No adenomatous portion was found in the tumor. There was no vessel involvement and the resected lymph nodes showed no evidence of metastasis. Immunohistochemically, CEA and CA 19-9 were diffusely positive within the tumor. Positive staining of CA 15-3 was seen only in an invasive area of the tumor.