粘膜下腫瘍様の形態を呈した早期胃粘液癌の1例

Early Mucinous Gastric Carcinoma with Submucosal Tumor-like Morphology, Report of a Case

要旨●患者は60歳代，男性．EGDで胃噴門部に隆起性病変を指摘され，生検で診断が確定しないため当院へ紹介され受診となった．噴門部前壁に立ち上がりなだらかな10mm大の粘膜下腫瘍様の隆起性病変を認め，中央部が陥凹し多量の粘液が付着していた．NBI併用拡大観察で，陥凹内に乳頭状構造，陥凹辺縁部に不整な微小血管構築像を認めた．EUSでは，第2〜3層に隔壁を有する低エコー性腫瘤を認めた．診断的治療目的でESDを施行し，病理組織学的に上皮下に粘液結節を伴い，粘膜下層に浸潤した胃粘液癌と診断した．早期胃粘液癌の報告は希少であり，診断には粘膜下腫瘍様の形態に加え，陥凹部の粘液付着と乳頭状構造に注目すべきと考えられた．

　A 60-year-old man was referred to our hospital because of an elevated lesion in the gastric cardia. The lesion was not diagnosed by biopsy. Endoscopic examinations detected a 10-mm-diameter lesion appearing as a sessile submucosal tumor with mucous in the central depression. Magnifying endoscopy with narrow-band imaging represented a fine papillary structure in the depressed region and irregular microvascular architecture in the margin. Endoscopic ultrasound imaging demonstrated a hypoechoic area with a septum in the third layer. Thus, endoscopic submucosal dissection was performed for diagnostic treatment. Histopathological examination of the lesion revealed a gastric mucinous carcinoma invading the deep submucosa. Given the few reports on the early mucinous gastric carcinoma submucosal appearance, mucous, and papillary structure in the depressed can help in the diagnosis.