Helicobacter pylori除菌療法後に消失した上行結腸MALTリンパ腫の1例

Regression of Mucosa-Associated Lymphoid Tissue Lymphoma of the Ascending Colon after Helicobacter Pylori Eradication Therapy

要旨　68歳，男性．検診での便潜血反応陽性に対する大腸内視鏡検査でS状結腸ポリープを認め，当科紹介受診．S状結腸のIp型早期癌を内視鏡的切除した際，上行結腸に径2cm大の粘膜下腫瘍を認めた．生検組織の病理診断および免疫グロブリン重鎖遺伝子再構成の分子生物学的検査にてMALTリンパ腫と診断した．患者の全身状態が不良である点とH. pylori除菌療法で直腸MALTリンパ腫が消失した報告に基づいて，胃でのH. pylori感染を確認後に除菌療法を施行した．除菌療法1か月後に除菌の成功を確認し，大腸内視鏡検査にて腫瘍は径4mm大の結節が3個と縮小傾向を示した．除菌療法8か月後の大腸内視鏡検査で，腫瘍は消失していた．大腸MALTリンパ腫に対する除菌療法の有効例は本症例を含めて17例報告されている．

　A 68-year-old man was admitted to our department for the treatment of a sigmoid colon polyp diagnosed by a colonoscopic examination performed on account of positive fecal occult blood test. When the polyp was endoscopically resected, a submucosal tumor of 2 cm in diameter was incidentally found in the ascending colon. Histological examination of the biopsy specimens and polymerase chain reaction analysis of the immunoglobulin heavy chain rearrangement revealed that the tumor was a mucosa-associated lymphoid tissue lymphoma (MALT lymphoma). Based on a report that rectal MALT lymphoma regressed with H. pylori eradication therapy, the eradication therapy was attempted on this patient partially because he was not fit and well. His stomach was positive for H. pylori infection. One month after the therapy, the eradication proved successful and a colonoscopic examination demonstrated that the MALT lymphoma had remarkably regressed into 3 nodules each of which was 3～4mm in diameter. On colonoscopy 8 months after the therapy, the tumor had disappeared. Including this patient, 17 cases of colorectal MALT lymphoma have been reported so far that have regressed after H. pylori eradication therapy.