0-IIc型の通常型早期胃癌との鑑別が困難であった胃底腺粘膜型腺癌の1例

Gastric Adenocarcinoma of the Fundic-gland Mucosa Type Mimicking Early Gastric Cancer of Type 0-IIc, Report of a Case

要旨●60歳代，男性．H. pylori除菌後の定期の上部消化管内視鏡検査（EGD）で，萎縮粘膜を背景に胃体中部小彎に10mm大の境界明瞭な発赤調陥凹性病変を認め，軽度の上皮下腫瘍様隆起を伴っていた．0-IIc型の通常型早期胃癌の診断でESDを施行した．病理組織学的には，腫瘍の深層は胃底腺へ分化を示す腫瘍を認め，浅層では腺窩上皮へ分化を示す腫瘍で構成され，それぞれの層構造が保たれていたことから，胃底腺粘膜型腺癌（Ueyama・Yao分類のType 1）と診断された．辺縁部の一部は非腫瘍性上皮に被覆されていた．既感染胃粘膜を背景とした境界明瞭な発赤陥凹型の早期胃癌は，胃底腺粘膜型腺癌との鑑別が困難な症例が存在することがあるため注意が必要である．

　The patient was a 60-year-old man who had undergone Helicobacter pylori eradication. He underwent esophagogastroduodenoscopy at our hospital, and a gastric lesion was detected during the procedure. White-light imaging revealed a 10mm- reddish, depressed lesion with a subepithelial lesion-like shape in the lesser curvature of the middle third of the stomach. This lesion was diagnosed as a differentiated early gastric cancer of type 0-IIc based on endoscopic findings and biopsy results, after which ESD was performed. ESD histopathology revealed that the tumor differentiated to not only the foveolar epithelium but also the fundic gland and mucous neck cell. Our final diagnosis was gastric adenocarcinoma of fundic-gland mucosa type（classification of Ueyama and Yao, Type 1）. Early gastric cancer of the reddish and depressed type that occur in atrophic gastric mucosae can be difficult to distinguish from adenocarcinoma of the fundic-gland mucosa type ; therefore, caution should be exercised.