Helicobacter pylori除菌で一旦消失したlow-grade MALTリンパ腫が3年後にhigh-grade MALTリンパ腫として再発した1例

Relapse of MALT Lymphoma Three Years after the Initial Antibiotic Therapy for Helicobacter pylori, Report of a Case

要旨　Helicobacter pylori（以下Hp）の初回除菌療法で一旦消失したlow-grade MALTリンパ腫が，その3年後にhigh-grade MALTリンパ腫として再発した1例である．本例は，初回除菌療法前には．一部にhigh-grade MALTリンパ腫を疑わせる肉眼所見を認めたものの，組織学的にはlow-grade MALTリンパ腫の所見のみが得られていた．再発時には以下の点が注目された．すなわち，①再発時の小びらん所見で，良性びらんとは異なるぎざぎざした不整形で，一部枝分かれした肉眼所見が認められた．②再除菌施行でHpが陰性化したが，その後に急速にリンパ腫の増悪が認められた．手術材料の病理診断は，所属リンパ節への転移を認めるhigh-grade MALTリンパ腫（B細胞性．一部でT・B両形質発現を示す．）であった．

　We report an operated case of recurrence of mucosa-associated lymphoid tissue (MALT) lymphoma in a 58-year-old female. In our previous report, the case was diagnosed as a low-grade MALT lymphoma with Helicobacter pylori (Hp) by macroscopic (Fig.2), pathological, and molecular biological findings. After initial antibiotic therapy, both macroscopic and microscopic studies (Fig.3) including immunohistochemistry and molecular biology revealed no evidence of lymphoma, but Hp remained detectable. Follow-up studies showed no recurrence for 30 months, during which 50～100 mg of cyclophosphamide was administrated to the patient. In the examination performed 36 months after initial antibiotic therapy, the recurrence of lymphoma was detected as small and irregular-shaped erosions (Fig.6 c, d) at the large curvature of the corpus. The second course of antibiotic therapy using 20 mg of sodium rabeprazole, 600 mg of clarithromycine, 1,500 mg of amoxicillin, and 54,000 units of pronase completely eradicated Helicobacter pylori, but the finding of lymphoma still remained. The last examination performed three months after the second course of eradication therapy revealed the exacerbation of lymphoma (Fig.8). The operated specimen showed a high-grade MALT lymphoma with metastasis to the regional lymph nodes.

　The initial and follow-up studies were re-evaluated, and we conclude that the lesion was a high-grade MALT lymphoma from the initial stage of the clinical studies.