PPI関連胃底腺ポリープに発生した胃型腺腫の1例

Fundic Gland Polyp with Gastric-type Adenoma during Long-term Proton Pump Inhibitor Administration, Report of a Case

要旨●患者はPPI長期内服歴がある70歳代，男性．胃体下部大彎に増大傾向のある12mm大の白色調隆起性病変を認め，水腫様変化を有し，表面構造は微細顆粒状であった．NBI併用拡大観察（ME-NBI）では，微小血管構築像はWOSにより視認できずabsent，表面微細構造はregularと判断したが，弱い不整を認めたことからPPI関連胃底腺ポリープ（FGP-PPI）に発生した低異型度の上皮性腫瘍が考えられ，EMRにて切除した．病理組織学的所見では，胃型形質を呈する低異型度の上皮性腫瘍の増生を認め，非腫瘍部ではFGP-PPIに特徴的な病理組織像を示し，FGP-PPIより発生した胃型腺腫と診断した．FGP-PPIに表面構造の不整やWOSなどの非典型的な所見がみられた場合，腫瘍の合併を考慮しME-NBIを用いた精査や生検を考慮する必要がある．

　A male patient in his 70s had taken PPI（proton pump inhibitors）for >10 years. A 12-mm whitish elevated lesion with enlargement in the greater curvature of the lower third of the stomach was discovered during an esophagogastroduodenoscopy. White light imaging showed a slightly cystic appearance, suggesting a FGP-PPI（fundic gland polyp associated with PPI）. Magnifying narrow-band imaging showed a slightly irregular microsurface pattern with a white opaque substance. We performed endoscopic mucosal resection for the lesion, considering low-grade epithelial tumors with FGP-PPI. Pathological findings showed an adenoma with a gastric phenotype coexisting with a non-tumorous area, which showed characteristic histopathological findings of FGP-PPI. Magnifying narrow-band imaging may be useful for assessing the coexistence of tumors with FGP-PPI.