胃MALTリンパ腫に対するH. pylori除菌治療後にdiffuse large B-cell lymphomaが出現した1例

Gastric Diffuse Large B-cell Lymphoma which Progressed Rapidly after Helicobacter pylori Eradication for MALT Lymphoma, Report of a Case

要旨　73歳，男性．近医での上部消化管内視鏡検査にて，胃印環細胞癌を疑われ，当院を紹介受診した．当院での再検では胃体部から前庭部にかけて浅いびらんと粘膜の凹凸不整を認め，生検にて低悪性度胃MALTリンパ腫と診断された．Helicobacter pylori（H. pylori）感染は陽性で，API2-MALT1遺伝子異常を認めなかったため，除菌療法を施行した．除菌療法終了6週後に上部消化管内視鏡検査を施行したところ，H. pyloriは陰性化し，病変部の大部分の粘膜は平滑，褪色調となっていたが，胃角小彎後壁に不整形の潰瘍性病変の出現を認め，同部からの生検にてdiffuse large B-cell lymphomaと診断された．放射線化学療法施行後，完全寛解となり，経過観察中である．

　A 73-year-old male patient was referred to the Department of Endoscopy, Hiroshima University Hospital for further examination of abnormal endoscopic findings in the gastric corpus. Endoscopic study of the stomach revealed granular mucosa with multiple small erosions from the corpus to the antrum. He was diagnosed by endoscopical and histological examination in our hospital as having a low grade of MALT lymphoma with signet-ring carcinoma cell-like cells. Helicobacter pylori infection was diagnosed by both histological and serological examination. API2-MALT1 chimeric transcript was not detected. 6 weeks after H. pylori eradication, an irregular-shaped ulcerative lesion appeared on the posterior wall of the angulus despite regression of the other lesions. Histological findings of the biopsy specimens from the ulcerative lesion revealed massive infiltration of atypical large lymphoid cells and the lesion was diagnosed as a diffuse large B-cell lymphoma. He received chemotherapy and radiotherapy, and the ulcerative lesion has completely disappeared.

　1) Department of Medicine and Molecular Science, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan