潰瘍瘢痕として経過観察され，リンパ管侵襲が著明であった0-Ⅱc型早期胃癌の1例

Type 0-Ⅱc Early Gastric Carcinoma with Severe Lymphatic Permeation, Followed Up as Gastric Ulcer Scar for 13 Years and Eight Months, Report of a Case

要旨　胃体下部後壁の胃潰瘍瘢痕として長期間経過観察されていた54歳の男性に，瘢痕の肛門側に隣接する0-Ⅱc型の早期癌を発見した．表面露出部は8×3mm大の小陥凹にとどまる印環細胞癌であったが，その周囲の粘膜深層，粘膜下層のリンパ管内を充実型の低分化腺癌が侵襲し，20×10mm大の拡がりを示していた．同部位はX線では胃小区間溝の目立たない淡いバリウム斑として，内視鏡では淡い槌色域を呈していた．また，第2群のリンパ節に転移がみられた．悪性サイクルの経過中に瘢痕の肛門側にのみ癌が残存し，その部の観察が不十分となり診断が遅れたものと考えられた．潰瘍の経過観察に際しては常に悪性の可能性を考慮した注意深い観察が必要であると考えられた．

　A 54-year-old male visited our hospital for further examination of gastric abnormality discovered during a screening x-ray examination in August 1997. By x-ray, endoscopy and endoscopic biopsy in December 1983. He was diagnosed having gastric ulcer scar in the lower corpus. The diagnosis was not changed until last year, even though several follow up studies were carried out. Eventually, a small depressed lesion (8×3 mm) was found near the anal side of the ulcer scar at this time, and endoscopoic biopsy revealed a poorly differentiated adenocarcinoma. Distal gastrectomy was performed. Histologic examination of the resected specimen revealed marked lymphatic permeation of a poorly differentiated adenocarcinoma in the submucosal and deep mucosal layer around the depressed area and it reached the distal side of the ulcer scar. However, the carcinoma was exposed to the surface only in the depressed area, and signet-ring cell carcinoma was seen in the mucosal layer. The poorly differentiated adenocarcinoma metastasized in the N2 lymph node. Retrospectively, the area of lymphtic permeation corresponded to a faint barium fleck on x-ray examination and a discolored area on endoscopy. The malignant cycle of this carcinoma was thought to have had a long history.