除菌治療が著効し長期間緩解を維持している表層型low-grade MALTリンパ腫の1例

Low-grade MALT Lymphoma of the Superficial Type Regressing after Helicobacter pylori Eradication Followed up by Endoscopic Examination Over a Long Time, Report of a Case

要旨　胃MALTリンパ腫の中には，Helicobacter pylori（以下H. p.）の除菌治療で緩解する症例と緩解しない症例が存在する．除菌治療前にそれを判別する方法，および除菌後の長期観察による形態変化についての報告は少ない．今回，除菌治療が著効した1例を呈示し，その判別方法および長期観察による形態変化に関して，文献的考察を加えて検討した．患者は72歳，男性．胃角から幽門前庭部に顆粒状の粘膜粗糙，多発性の不整形びらん，および発赤部と褪色部の混在した粘膜を認め，病理組織学的に，low-grade MALTリンパ腫と診断された．H. p.は陽性であったため，lansoprazole＋clarithromycin＋tinidazoleによる除菌治療を行ったところ，生検でMALTリンパ腫は消失した．除菌後3年以上経過しているが，MALTリンパ腫およびH. p.の再発はない．内視鏡所見では，発赤，びらんは消失し滑らかな萎縮性の褪色粘膜に変化した．

　Patients with gastric MALT (mucosa-associated lymphoid tissue) lymphoma have been divided into two groups (the regression and the non-regression group) after Helicobacter pylori (H. p.) eradication. However, few investigators have reported what type of MALT lymphoma will regress due to H. p. eradication. We reported a case of low-grade MALT lymphoma which regressed with H. p. eradication and discussed the difference between the regression and non-regression group, and the morphological changes after H. p. eradication from reviews of the literature. In a 72-year-old male, the endoscopic examination revealed coarse granular mucosa, multiple irregular erosions, and mixed reddish and whitish mucosa spreading in the gastric angulus to the antrum. The histological specimens from endoscopic mucosal resection were diagnosed as low-grade MALT lymphoma. Because H. p. examination was possitive, H. p. eradication was performed with tripple therapy consisting of a two-week course of oral lansoprazole, clarithromycin and tinidazole. The pathological biopsy specimens after H. p. eradication showed that MALT lymphoma had disappeard and H. p. examination gave negative results. The endoscopic examination after H. p. eradication revealed that the reddish and erosive gastric lesions had disappeared and changed into smooth whitish lesions. For over three years without any treatment the patient has experienced no relapse of MALT lymphoma or H. p..

　Some reports and our case suggest that the regression group after H. p. eradication can be predicted by a combination of the endoscopic and histological findings, and examination by endoscopic ultrasonography. Moreover, when reddish and erosive gastric lesions in patients with low-grade MALT lymphoma of the superficial type have changed into no erosive and smooth whitish lesions after H. p. eradication, we can presume the histological regression of MALT lymphoma.