Helicobacter pylori未感染胃粘膜の前庭部に発生した腸型優位の形質を発現する高分化管状腺癌の1例

Well-differentiated Tubular Adenocarcinoma with a Predominantly Intestinal Phenotype Pattern in the Gastric Antrum of a Helicobacter pylori-negative Patient, Report of a Case

要旨●患者は30歳代，女性．人間ドックの上部消化管内視鏡検査にて前庭部異常を指摘され当院を受診，内視鏡的に前庭部に隆起性病変を認め，生検組織診でGroup 4と診断された．精密胃X線造影・内視鏡所見では背景粘膜に萎縮・胃炎の像はみられず，生検組織診ではUSS（The Updated Sydney system）に準じた組織学的胃炎の所見を認めず，また血清H. pylori抗体，尿素呼気試験も陰性だった．早期胃癌0-IIa＋IIc型の診断でESDを施行し，病理組織学的には，腸型優位の形質を発現する高分化管状腺癌（粘膜内癌）の所見であった．H. pylori未感染胃粘膜の幽門腺領域に腸型形質の分化型胃癌が発生することは極めてまれと思われ，文献的考察を加えて報告した．

　A woman in her thirties was admitted to our hospital for examination of abnormal gastric antral findings detected by screening EGD（esophagogastroduodenoscopy）. Both radiographic studies and EGD revealed an elevated lesion in the gastric antrum that was Group4 histologically by endoscopic biopsy. There was no histological evidence of atrophy or gastritis of the background mucosa and no histological gastritis according to Updated Sydney system. The serum Helicobacter pylori（H. pylori）antibody titer and urea breath test were negative. We performed endoscopic submucosal dissection of this lesion with a diagnosis of early gastric cancer（IIa＋IIc）. Examination of the resected specimen revealed at the lesion was a well-differentiated tubular adenocarcinoma with predominantly intestinal histology. It is considered to be extremely rare for differentiated gastric cancer of the intestinal type to occur in the pyloric gland area of a H. pylori negative patient. Accordingly we reported this case with discussion of the literature.