胃MALTリンパ腫除菌後の長期経過と予後―内視鏡像を中心に

Long-term Observation and Prognosis of Gastric MALT Lymphomas after H. pylori Eradication

要旨　H. pylori除菌療法を施行した胃MALTリンパ腫の長期経過と予後について，内視鏡像を中心に，自験例をもとに概説した．除菌療法奏功例では内視鏡像の改善を認め，除菌後1年以内には病理組織学的にも約90％の症例でCRと判定された．CR症例では病変のあった部位は萎縮様褪色粘膜へと変化し，この変化はCR判定後3年以上の経過観察においてもほとんど消失することなく持続していた．組織学的にも，消失した固有胃腺はわずかながら回復はするものの，周囲粘膜と全く同程度までに回復する症例はほとんどなかった．一方，除菌無効例はほとんどがH. pylori陰性かつAPI2-MALT1キメラ遺伝子陽性例であった．このような症例に対しては放射線療法が有効であったが，3年以上の無治療経過観察でも病変の増悪を認めないものもあり，今後さらなる症例の集積が必要であると考えられた．

　The present article summarized our long-term observations of gastric MALT lymphomas after H. pylori eradication. Successful eradication of the bacterium brought approximately 90 ％ of the patients to complete remission (CR) within 1 year after therapy. Endoscopic findings of gastric lesions showed amelioration in the CR cases and turned into localized atrophic areas with discolored appearances ; which features were unchanged during endoscopic following-up for more than 3 years. Histological reconstruction of gastric mucosa affected by the disappearance of lymphoma cells,‘empty lamina propria' was also persistent in these areas. Non-responders to bacterial eradication were associated with the absence of H. pylori infection and the presence of API2-MALT1 chimera gene. Irradiation therapy was a good option for these patients to gain complete remission. However, the cases rejecting additional therapy showed no deterioration in the primary lesions or systemic expansion of the disease during their long-term observation. The strategy for the cure gastric MALT lymphomas still involves quite a few issues to be solved. Further studies are warranted.

　1) Division of Gastroenterology, Tohoku University Hospital, Sendai, Japan