径10mmの早期癌類似進行癌（肛門管癌）の1例

Advanced Anal Cancer Mimicking an Early Cancer, Report of a Case

要旨　患者は70歳，女性．主訴は排便・排ガス後の出血．1988年末から肛門出血を自覚したが放置していた．1989年3月近医を受診し，肛門部隆起性病変を指摘され当科紹介となった．anal vergeから1.5cm，9°方向に径10mmの，中心に陥凹を有するやや硬い隆起性病変（Ⅱa＋Ⅱc）を認め，生検の結果，中分化腺癌であった．超音波内視鏡（EUS）では，肛門管右壁に径約10mmの腫瘤像を認め，pm層への浸潤が疑われた．腫瘍径と年齢を考慮し，肛門機能を温存すべく局所切除を施行したところ，病理組織所見で筋層に達する大きさ10×10mmのpapillotubular adenocarcinomaで，深達度a₁，ly（＋），v（－）であった．ly（＋）であったため根治術の適応と判断し，腹会陰式直腸切断術を追加施行した．腫瘍径の小さい肛門管癌の治療方針決定にEUSは必須の検査法と考えられた．

　A 70-year-old female with a complaint of anal bleeding with defecation was admitted to our surgical department. A slightly elevated tumor with a central depression, 10 mm in size, mimicking a type Ⅱa＋Ⅱc lesion was found in the upper part of the anal canal. Endoscopic ultrasonographic examination suggested invasion to the pm-layer, however, we initially selected local excision of the tumor because of its size and her age. Histological examination of the removed specimen disclosed invasion to the muscular layer with lymphatic infiltration. Miles' operation was performed. We would like to emphasize the important role of EUS for the diagnosis of small tumors in the anal canal.