除菌後に発見され診断に苦慮した胃癌の1例

Early Gastric Cancer Detected after Helicobacter pylori Eradication, Report of a Case

要旨●患者は60歳代，男性．1年前にH. pylori除菌が成功．胃X線健診を機に近医で胃癌と診断されため，当院に紹介され受診となった．当院の上部消化管内視鏡検査では病変は胃体下部小彎に認め，粘膜は淡く発赤しており，境界は不明瞭であった．NBI併用拡大観察では，病変中央部の表面微細構造と微小血管構築像はirregularであり，癌と診断することは容易であった．しかし，特に口側境界では，表面微細構造は均一でirregularityに乏しく，微小血管構築像の所見より正確に境界診断が可能であった．ESDにて一括切除を行い，病理組織学的所見では病変口側の表層は非癌粘膜が被覆していた．H. pylori除菌後に発見される胃癌は質的診断や境界診断が困難であるとされ，そのことを念頭に置いて注意深い観察が必要であると思われる．

　The patient was a 60-year-old man who had a Helicobacter pylori（H. pylori）infection that had been eradicated. He was diagnosed with early gastric cancer and referred to our hospital for detailed examination. He underwent upper gastrointestinal endoscopy. The lesion was light red in color, but the margins of the lesion were unclear using conventional endoscopy, especially towards the oral side. When observed using ME-NBI（magnifying endoscopy with narrow-band imaging）, the microsurface pattern of the lesion was regular, but the microvascular pattern was irregular. The margins of the lesion were detected using ME-NBI, and therefore, endoscopic submucosal dissection was performed to resect the lesion. The resected specimen revealed that the superficial epithelium of the lesion was non-cancerous. This finding was the reason for the difficulty in detecting the margins of the lesion. Sometimes, diagnosing early gastric cancer that is detected after H. pylori eradication is difficult. This should be taken into account, and careful endoscopy must be performed.