横行結腸に発生したⅡc型早期癌の1例

Ⅱc (depressed) Type Early Carcinoma of the Transverse Colon, Report of a Case

要旨　患者は73歳，男性．4年前にS状結腸癌にてS状結腸切除術を受けており，follow-upの大腸ファイバースコープによる検索により横行結腸にdiffuseな発赤所見を指摘され，生検にて癌の診断，横行結腸部分切除術を施行した．病変は7×5mmの浅い陥凹を呈するⅡc型早期癌で，粘膜筋板まで達する高分化腺癌であった．また病変内に異型腺管の混在を認めた．内視鏡像では空気量を加減することにより形態が変化し，空気量を増すことによりⅡc型を呈し，減ずることにより周囲の隆起が著明になった．この所見は発赤病変で発見される大腸のⅡc型早期癌の1つの特徴であると考えられた．

　We report here a case of 7×5 mm sized, superficially depressed type early colon cancer.

　The patient, 73-year-old male had a history of which was resected four and a half years ago. Periodic follow-up colonofiberscopy showed a superficial depression with redness in the transverse colon. This proved to be a cancer by biopsy. Barium enema study was not capable of pointing out the lesion. A transverse colectomy with lymph node dissection was perfomed following the resection line indicated by colonofiberscopy. The resected specimen had a slightly depressed erythematous lesion, measuring 7×5 mm in diameter histologically. It was a well differentiated adenocarcinoma with negative lymph node metastasis.

　It remains to be shown whether a seemingly low incidence of superficially depressed type colorectal cancer reflects a true incidence or poor ability of diagnosing it. Endoscopists, at any rate, should remember that colorectal cancer can exist in a superficially depressed (Ⅱc) lesion with redness.