胃原発濾胞性リンパ腫の1例

Primary Gastric Follicular Lymphoma, Report of a Case

要旨●患者は40歳代，男性．検診胃X線検査で異常を指摘され近医を受診し，上部消化管内視鏡検査（EGD）で胃に多発した隆起性病変を認めたため，精査加療目的にて当院へ紹介され受診した．EGDでは胃穹窿部に20mm大，胃体上部大彎に15mm大，5mm大の粘膜下腫瘍様隆起を認め，生検の結果，いずれの病変も濾胞性リンパ腫と診断された．超音波内視鏡検査では濾胞構造を反映した小円形の低エコーを認めた．FDG-PETでは胃穹窿部病変のみに異常集積を認めたため，形質転化の可能性も含め，同病変に対してtotal biopsy目的に内視鏡的粘膜下層剝離術（ESD）を施行した．ESD切除標本の病理組織診断では形質転化は認めなかった．

　A 46-year-old male was referred to our hospital as part of a group stomach checkup. Upper gastrointestinal radiography revealed an abnormality, and further examination was recommended. Esophagogastroduodenoscopy revealed three submucosal tumor-like lesions：20mm in diameter in the fornix and 15 and 5mm in diameter in the greater curvature of the upper part of the stomach.

　Histopathological findings of endoscopic biopsy specimens obtained from the three lesions revealed follicular lymphoma. Endoscopic ultrasonography revealed hypoechoic lesions accompanied with small follicle-like structures. We suspected that the fornix lesion has a malignant transformation because of its abnormal uptake in fluorodeoxyglucose-positron emission tomography. To conduct total biopsy for obtaining an accurate histopathological diagnosis, we performed endoscopic submucosal dissection of the fornix lesion. However, malignant transformation remained undetected in the endoscopic submucosal dissection specimen.