A型胃炎の経過追跡中に前庭部に発見した早期胃癌の1例

A Case of Early Gastric Cancer with Type A Gastritis

要旨　患者は52歳，女性．2002年にA型胃炎と診断し，定期的に経過追跡を行っていた．経過中，2007年2月の上部消化管内視鏡検査にて前庭部大彎に0IIc型胃癌を認め，内視鏡的粘膜下層剥離術にて切除した．病理組織学的には萎縮に乏しい幽門腺粘膜内の0.3cm大，粘膜内の高分化型管状腺癌であった．A型胃炎はcarcinoidとならび腺癌の発生母地としても考えられている．A型胃炎を背景とした胃癌は，萎縮した体部に認めることが多いとされているが，本例のように萎縮に乏しい幽門腺粘膜内に発生することもあり，全胃を観察することが重要と考えられた．

　A 52-year-old female patient was diagnosed with type A gastritis in 2002 and has been under periodic follow-up since. Upper gastrointestinal endoscopy, performed in February 2007, revealed findings suggestive of type 0IIc gastric cancer in the greater curvature of the antrum, and endoscopic submucosal dissection was performed. The histopathological diagnosis was well-differentiated tubular adenocarcinoma, 0.3cm in diameter, localized in the pyloric gland mucosa, and associated with few atrophic changes. Type A gastritis as well as carcinoid have been reported as predisposing factors for adenocarcinoma of the stomach. Gastric cancer occurring in patients with type A gastritis commonly develops in the corpus, associated with mucosal atrophic changes. However, as observed in our patient, adenocarcinoma in such patients can also arise from the pyloric gland mucosa and be associated with few atrophic changes. It is thus essential to examine the entire stomach during follow-up endoscopy in patients with type A gastritis.