ESDを施行した胃底腺型腺癌の1例

抄録

A 72-year-old man was diagnosed by endoscopy─which suggested well differentiated tubular adenocarcinoma Group 4─and admitted to our hospital. The lesion was located in the upper third of the stomach on the posterior wall, was flatly depressed (0-IIc), and had an undefined margin under indigo carmine dyeing. Histologically, the lesion was composed of cells resembling chief cells and indicated differentiation to fundic glands. Immunohistochemically the lesion indicated MUC6(+), MUC5AC(-), CD10(-), MUC2(-), gastric phenotype. We diagnosed this lesion as gastric adenocarcinoma, fundic gland type. Gastric adenocarcinoma of fundic gland type was proposed by Ueyama and Yao et al in 2010, and its clinicopathologic features reported. This type of lesion tends to invade submucosally and it is recommended to treat using ESD. For this reason we elected to perform endoscopic submucosal dissection (ESD) rather than endoscopic mucosal resection (EMR). The lesion─SM1 (250μm)─was completely excised. No relapse has been detected from surgery until follow up examination. Most of these cancers originate from normal mucous membrane, and are thought to be unassociated with H. pylori. As infection rate of H. pylori decreases, this type of adenocarcinoma should be considered in the future.