大きさ8mmの大腸mp癌の1例

Small Colonic Cancer 8 mm in Size with Invasion of the Muscularis Propria Layer, Report of a Case

要旨　患者は71歳，男性．検診で発見され，X線所見では，下行部結腸に類円形の隆起性病変を示し，正面像で病変に向かう粘膜ひだの集中および側面像で角状変形を認めた．内視鏡所見で中心陥凹のある盤状隆起を認めた．切除標本の肉眼所見は，大きさ8×8mm，表面はびらん状で，溝状の陥凹を呈する盤状隆起性病変で，組織像は高分化腺癌，癌の主座はsmにあって，一部固有筋層に及んでいた．10mm未満の大腸癌で，sm癌とmp癌の鑑別診断には，本例を含めた7例の報告の検討から，X線所見では，側面像の変形と正面像の粘膜ひだの集中，内視鏡的には，粘膜ひだの集中とともに，生検鉗子による病変の可動性を検討することが必要であると考えられた．

　A 71-year-old man was admitted to our hospital for a health check using colonoscopy. Barium enema disclosed a small oval flat elevation on the descending colon. The frontal view showed converging folds towards the oval elevation, and the lateral view showed angled deformity. Colonoscopy showed a disc-like elevation with central depression. The resected specimen contained a round flat elevation with converging folds, 8 × 8 mm in size. Histological examination disclosed a well-differentiated tubular adenocarcinoma, slightly invading the muscularis propria layer. No lymph node metastasis was detected. From an analysis of seven cases less than 10 mm in size with invasion of the muscularis propria layer, it was shown that for the differential diagnosis between sm cancer and mp cancer, it is necessary to study the converging fold toward the small flat elevation and the mobility of small lesion by biopsy-forceps.