右側結腸に同時および異時性に表面型大腸癌が多発した1例

Multiple Superficial Colorectal Carcinomas in the Right Side Colon, Report of a Case

要旨　患者は75歳，男性．1996年9月，便通異常を主訴に近医受診．大腸内視鏡検査（CF）にて上行結腸にポリープを指摘され，当院紹介となる．当院のCFにて，上行結腸に13×10mmのⅡa＋Ⅱcと，近傍に13mmのⅡa（LST-NG）を認めた．また，横行結腸にも，12mmのⅡa（LST-NG）を認めた．横行結腸のⅡaに対しては，ポリペクトミーが施行されたが，上行結腸のⅡa＋Ⅱcは，sm massiveと診断し，同年10月11日，上行結腸切除術が行われた．病理結果は，Ⅱa＋Ⅱcは高分化腺癌（sm₂，ly₀，v₀，n₀）であり，近傍のⅡaも高分化腺癌（m，ly₀，v₀），更にポリペクトミーされた横行結腸肝彎曲部のIlaも高分化腺癌（m，ly₀，v₀）であった．また，術後9か月に行われたCFで，横行結腸に12mm大のⅡaを認め，EMRを施行したところ，高分化腺癌（m，ly₀，v₀）であった．更に，術後2年1か月後に行われたCFにて横行結腸に10mm大のⅡaを認め，EMRにて，高分化腺癌（m，ly₀，v₀）の診断を得た．以上，同時，異時性に5つの大腸癌の発生を認めた症例を経験した．いずれも肉眼型は表面型であり，発生部位は右側結腸に限局していた．

　Colorectal polyps were detected in a 75-year-old man by colonoscopy at a nearby hospital, when he visited there complaining of abdominal discomfort. Endoscopic examination revealed two superficial colorectal cancers type Ⅱa+Ⅱc (13 mm in size) and type Ⅱa (13 mm in size) in the ascending colon, and one type Ⅱa cancer (12 mm in size) in the transverse colon. Preoperative di-agnosis was early colorectal cancer of type Ⅱa+Ⅱc with massive invasion to the submucosal layer. Type Ⅱa in the transverse colon was removed endoscopically before the operation and histological examination showed that it was a well-differentiated adenocarcinoma with intramucosal invasion. Partial colectomy was performed, and histological diagnosis was that the type Ⅱa+Ⅱc cancer was a well-differentiated adenocarcino-ma with massive invasion of the submucosal layer (sm₂, ly₀, v₀, n₀), and the type Ⅱa cancer was a well-differentiated adenocarcinoma with intramucosal invasion. Nine months later, colonoscopy revealed a superficial colorectal tumor of type Ⅱa at the same site. It was 12 mm in size. Endoscopic mucosal resection was performed on this tumor, and the resected specimen showed a well-differentiated adenocarcinoma with intramucosal invasion. Two years and one month later, colonoscopy revealed a superficial colorectal tumor of type Ⅱa at the same site. It was 10 mm in size. The resected specimen showed a well-differentiated adenocarcinoma with intramucosal invasion. We thus reported a case of multiple superficial colorectal carcinomas in the right-side colon.