白色調・平坦陥凹型の胃底腺粘膜型腺癌の1例

Gastric Adenocarcinoma of Fundic-gland Mucosa Type Showing a White Depressed Appearance, Report of a Case

要旨●40歳代，女性．健診内視鏡検査で胃病変を認め，生検でGroup 5と診断され当院へ紹介され受診となった．胃体下部大彎前壁に10mm大，白色調の0-IIc型病変を認め，樹枝状の拡張血管を伴っていた．NBI併用拡大観察では非癌の診断であったが，辺縁部で窩間部開大の所見など上皮下腫瘍を示す所見を認め，胃底腺型腺癌と診断しESDを施行した．病理組織学的所見では，表層は非腫瘍性上皮に被覆され，上皮下で腺窩上皮と胃底腺への分化を示す腫瘍を認め，胃底腺粘膜型腺癌（Ueyama・Yao分類のType 3）と診断された．組織構築の類似性により，胃底腺粘膜型腺癌Type 3と胃底腺型腺癌との内視鏡的鑑別は困難と考えられた．

　A 40-year-old woman with previous Helicobacter pylori eradication underwent esophagogastroduodenoscopy at another hospital that revealed a gastric lesion. Biopsy examination showed Group 5 ; hence, she was referred to our hospital. White light imaging showed a 10-mm, white, 0-IIc lesion with dilatated vessels in the anterior wall of the pylorus. Magnifying endoscopy with narrow-band imaging revealed a noncancerous lesion. However, we diagnosed the lesion as a gastric adenocarcinoma of fundic-gland type because of dilated intervening parts at the edge of the lesion. Additionally, histopathological findings showed the tumor differentiate into the foveolar epithelium, fundic gland, and mucous neck cell under the nonneoplastic surface epithelium. The final diagnosis was gastric adenocarcinoma of fundic-gland mucosa type（according to the classification of Ueyama and Yao, Type 3） ; since, endoscopic differentiation between gastric adenocarcinoma of fundic-gland mucosa type（Type 3）and gastric adenocarcinoma of fundic-gland type is considered difficult.