リンパ節転移を伴ったⅡa＋Ⅱc型早期大腸癌の1例

Ⅱa＋Ⅱc Type Early Colonic Cancer with Lymph Node Metastasis, Report of a Case

要旨　患者は59歳，男性．無症状だが胃潰瘍歴があり検査目的で来院．一般血液検査，CEAに異常なく，UGIで潰瘍の再発なし．便潜血反応（Latex法）が陽性のため大腸X線検査を実施した．S状結腸に中央に淡いバリウム斑を伴う，輪郭が不整な平盤状病変を認め，側面像では腸管辺縁の変形は軽微であった．内視鏡検査で隆起の起始部粘膜が正常なⅡa＋Ⅱc型大腸癌と診断し手術した．病理所見は15×11mmの癌の粘膜下浸潤により形成されたⅡa＋Ⅱc型sm癌で，隆起の起始部粘膜は正常だった．腺腫部分は認めず，高分化型腺癌で，1つのリンパ節に転移を認めた．小さいながらもリンパ節転移を伴った興味ある大腸早期癌と考え報告した．

　An asymptomatic 59-year-old man visited our hospital because of anxiety about recurrence of gastric ulcer. Upper gastrointestinal examination revealed no recurrence of gastric ulcer and laboratory study no abnormality with the exception of positive immunochemical reaction for fecal occult blood. Subsequently performed barium enema examination showed a flat elevated lesion and a small polyp in the sigmoid colon. The flat elevated lesion was oval with irregular margin and had a central shallow depression. Endoscopic examination revealed that the elevated mucosa around the depressed area was normal.

　Operation was performed on November 21, 1988. The flat elevated lesion with central depression (Ⅱa＋Ⅱc type) measured 15×11 mm, macroscopically. Histological diagnosis was well differentiated tubular adenocarcinoma with extensive infiltration into the submucosal layer, but not into the deeper layers. Cancer cells were confined to the central depression in the mucosal layer, and the elevated mucosa around the depressed area was free from cancer cells. Cancer infiltration was found in only one of the removed lymph nodes.

　This case was featured by positive lymph node metastasis in spite of a small early colonic cancer with invasion into the submucosa.