早期胃癌とMALTリンパ腫が併存し，その診断に拡大観察が有用であった1例

Early Gastric Cancer Accompanied by Adjacent Gastric MALT Lymphoma in which Magnifying Endoscopic Observation was Useful for the Diagnosis, Report of a Case

要旨　早期胃癌と胃MALTリンパ腫が併存した病変に対し，拡大内視鏡観察が有用であった症例を経験した．NBI拡大観察にて胃MALTリンパ腫はリンパ濾胞様構造，pitの消失，病変内に周囲と同様の粘膜の介在，血管の拡張，蛇行，分岐を認めた．一方，早期胃癌（高分化腺癌）はNBI拡大観察にて血管の網目状構造，クリスタルバイオレット染色にてpitの大小不同を認めた．両病変が衝突していると考えられたためESDにて一括で切除し，その後H. pylori除菌を追加した．約2年が経過し，再発は認められていない．拡大内視鏡観察が両者の鑑別に有用であった．

　We report a rare case of early gastric cancer accompanied by adjacent gastric MALT lymphoma, both of which were well defined by magnified endoscopic observation with NBI（narrow-band imaging）. Characteristic findings of MALT lymphoma on magnifying endoscopy observation with NBI included irregular branching tree-like microvessels, lymphoid follicle-like structures, and disappearance of pit patterns, intervening with background mucosa of normal appearance. Representative findings of early gastric cancer, on the other hand, were fine network patterns of the abnormal microvessels using magnified endoscopy with NBI, while NBI-guided magnifying chromoendoscopic observation with crystal violet staining identified irregular-sized pits. Under a diagnosis of early differentiated gastric carcinoma accompanied by adjacent gastric MALT lymphoma classified into Stage I, endoscopic submucosal dissection was initially performed to remove the both lesions en bloc, followed by anti-H. pylori therapy. Both the lesions were successfully treated and neither local recurrence nor metastasis has been observed for 2 years. Magnified endoscopy is a useful tool for differentiating MALT lymphoma from gastric carcinoma.