MALTリンパ腫類似病変から急速に進展がみられた胃悪性リンパ腫の1例

Gastric Malignant Lymphoma which Progressed Rapidly from Superficial Ulcerative Type of Gastric Malignant Lymphoma (MALT Lymphoma), Report of a Case

要旨　64歳，男性．1988年8月，夜間の悪心を主訴に当院を受診し，胃内視鏡検査の結果，胃角部小彎の胃潰瘍瘢痕が認められた．以後，当院外来で経過観察中であった．1994年7月，胃内視鏡検査で，体下部～胃角前壁に多発する浅いびらんが新たに観察されたが，生検では明らかな悪性の所見は得られなかった．同年11月の胃内視鏡検査で胃角部小彎の胃潰瘍瘢痕，体下部～胃角前壁のびらんに加えて，前庭部の浅い陥凹性病変が認められた．びらんおよび陥凹性病変からの生検では異型リンパ球の浸潤が認められ，胃内視鏡所見と合わせて当初，低悪性度の胃MALTリンパ腫が疑われた．1994年12月に胃内のHelicobacter Pyloriの存在が確認され，除菌を施行したが，体下部～胃角前壁の病変が急速に増大したため，1995年3月，胃部分切除を施行した．切除胃では，体下部～胃角前壁に4.0×4.0cm大の決潰型腫瘤を認め，組織学的には悪性リンパ腫（non-Hodgkinリンパ腫，B-cell，びまん性，大細胞型）と診断した．なお，経過観察中に認められた前庭部の浅い陥凹性病変は消失していた．生検，X線，内視鏡を見直し，検討をしたところ，表層型の悪性リンパ腫が急速に増大し，典型的な決潰型悪性リンパ腫へ発育進展したものと思われた．

　A 64-year-old man, visited our hospital in August, 1988 with a 7-year history of gastric ulcer and occasional nausea at night. Endoscopic study of the stomach revealed multiple gastric ulcer scars. The patient was followed up as a gastric ulcer case for seven years. In July, 1994, endoscopy was performed and demostrated granular mucosa, and multiple small ulcerative lesions on the anterior wall of the gastric angle. Histology of the biopsy of the specimens showed no evidence of malignant change. In November, 1994, the endoscopic picture revealed depressed lesions with ulcerative change on the anterior wall of the gastric angle and antrum. Histology of the biopsy of the sections revealed proliferation of atypical large lymphoid cells in the gastric mucosa. The diagnosis of MALT (mucosaassociated lymphoid tissue) lymphoma was suggested.

　Helicobacter pylori was detected by both culture and rapid urease test using biopsy samples, so we tried antibiotic therapy for H. pylori. After treatment, endoscopic and radiographical findings became partially worse. In March, 1995, the patient was admitted to our hospital, and partial gastrectomy was performed in March, 1995. Macroscopic findings of the resected stomach showed a 4.0 × 4.0 cm ulcerating tumor on the anterior wall of the gastric angle and in the follow-up period, the lesions that had been detected in the antrum and lower body had disapperaed. Histologic study revealed diffuse, large-cell type malignant lymphoma invading as far as the proper muscle layer.

　This case showed that, in a short period of time after eradication of Helicobacter pylori, the tumor partially multiplied radically and partially disappeared.

　There has been no report of cases resembling the unique clinical course of this case.