腸上皮化生領域と完全一致した胃神経内分泌腫瘍の1例

Gastric Neuroendocrine Tumor Associated with Intestinal Metaplasia, Report of a Case

要旨●患者は40歳代，男性．胃癌検診で施行したEGDにて胃体部に病変を指摘されたため当科に紹介となった．EGDにてなだらかに立ち上がる径5mmほどの発赤した隆起病変を認め，病変の肛門側は発赤が目立った．NBI拡大観察では隆起部は大小不同の乳頭状構造を呈した．病変の肛門側は窩間部が開大した表面微細構造を呈し，窩間部には拡張・延長した血管を認めた．発赤した隆起部にはLBCを認めた．ESDを施行し，病理組織学的に神経内分泌腫瘍（neuroendocrine tumor；NET）G2と，腫瘍と完全一致した領域に腸上皮化生を認めた．A型胃炎の所見は認められなかった．内視鏡所見はSMT様に発育する胃癌との鑑別を要した．

　A man in his 40s was referred to our department after an elevated lesion was found in the body of his stomach on esophagogastroduodenoscopy. The slightly elevated reddish lesion was approximately 5mm in diameter, and it was conspicuously red on the anal side of the lesion. The lesion's surface showed an irregular papillary structure on magnified narrow-band imaging. The anal side of the lesion showed an irregular surface structure with an enlarged intervening portion, where dilated and elongated blood vessels were also found. A light blue crest was seen throughout the superficial epithelium. Endoscopic submucosal dissection was performed, and pathological examination of the resected specimen revealed that intestinal metaplasia covered the surface layer of a G2 neuroendocrine tumor, with the distribution of the two completely matching with each other. No findings of type A gastritis were observed. The endoscopic findings required differentiation from those of other gastric cancers that develop similarly as submucosal tumors.