Helicobacter pylori除菌療法後にdiffuse large B-cell lymphomaへ変化した胃原発low grade MALTリンパ腫の1例

Low Grade MALT Lymphoma of the Stomach Transformed to Diffuse Large B-cell Lymphoma after the Eradication of Helicobacter pylori

要旨　患者は51歳，女性．主訴は左季肋部痛．上部消化管内視鏡検査と全身精査の結果，深達度mのHelicobacter pylori（HP）陽性胃原発low grade MALTリンパ腫（Stage Ⅰ）と診断した．HP除菌療法施行6週後，胃角部小彎に扁平隆起が出現したためリンパ腫の増悪と考え胃全摘術を施行した．切除標本の隆起部はdiffuse large B-cell lymphoma，深達度ss，infα，med，ly2，v0，リンパ節転移を4saと4sbに認めた．術後にCHPO6クールの全身化学療法を施行し4年を経過した現在も寛解を維持している．

　A 51 year-old-female was admitted to our hospital complaining of left hypochondralgia. Gastrointestinal endoscopy revealed edematous, subtranslucent and discolored mucosa from the lower gastric body to the antrum. Small erosions were observed on the surface of the lesser curvature of the gastric angle. These findings suggested a malignant lymphoma spread out in the mucosal and submucosal layer of the gastric wall. Rapid urease test was positive. The histological findings of the biopsy specimens showed an extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type. Six weeks after eradication therapy for HP, a flat mucosal elevation appeared in the lesser curvature of the angle. Total gastrectomy was performed because the follow-up findings suggested the progression of the disease. The investigation of the resected specimen led us to change the preoperative diagnosis to diffuse large B-cell lymphoma. Additional systemic chemotherapy (6 courses of CHOP) was performed. The patient has been in complete remission for more than 4 years.