IIc型早期大腸癌と鑑別を要したS状結腸潰瘍の1例

Benign Colonic Ulcer Showing Depressed-Type Early Colon Cancer (Type IIc), Report of a Case

要旨　患者は61歳の男性．主訴は便潜血反応陽性精査．注腸X線検査ではS状結腸に最大径7mm，多方向よりひだ集中を伴う陥凹性病変を認めた．ひだの先端は腫大し，中央にほぼ均一に淡くバリウムの溜まりを認めた．内視鏡検査では辺縁に隆起を伴う不整形の陥凹性病変として認められた．陥凹部の大半は発赤調であるが，拡大観察を行うと大半は無構造で一部に絨毛状構造を呈していた．陥凹辺縁の不整像は認めなかった．当初，粘膜下層深部まで浸潤するIIc型早期大腸癌を疑い外科的切除も考慮したが，生検結果で腫瘍の所見は認められず経過観察とした．6か月後の内視鏡検査にて瘢痕化を確認している．大腸に単発，孤立性に陥凹性病変を認めた場合，このような良性潰瘍の存在も念頭に入れ，診断にあたることが肝要であると考えられた．

　A 61-year-old man visited our hospital for further examination because of a positive fecal occult blood test. Barium enema examination revealed a shallow depressed lesion measuring 7 mm in size with converging folds in the sigmoid colon. Initial colonoscopy showed a reddish depression with marginal elevation and irregular margin. On magnifying colonoscopy, the depressed area was found to consist mostly of a non-structural area and partially of an area with villous-like appearence. At first, this lesion was diagnosed as a depressed-type early colon cancer (type IIc) with massive submucosal invasion, but pathological examination revealed no findings of neoplastic changes. Six months later, colonoscopy showed a healed ulcer and the lesion was diagnosed as a benign colonic ulcer. This case was interesting, considering the diagnosis of a solitary depressed lesion of the colon.