消化管アミロイドーシスの臨床像―画像診断を中心に─胃・十二指腸病変の特徴

Clinicopathological and Endoscopic Features of Upper Gastrointestinal Lesions in Patients with Amyloidosis

要旨　自験消化管アミロイドーシス46例の上部内視鏡所見，および生検組織所見を遡及的に検討し，十二指腸病変の推移も解析した．胃病変の内視鏡像は，AL型で粘膜下腫瘍様隆起を，AA型で微細顆粒状粘膜と結節状小隆起の多発を特徴としていた．十二指腸病変では，AL型において粘膜下腫瘍様多発隆起が高頻度に認められ，その出現率は軽度沈着例においても50％であった．一方，AA型では粗糙・顆粒状粘膜を高率に認めたが，アミロイド高度沈着例でも異常所見を示さない症例が存在した．また，約半数の症例では内視鏡所見や組織所見に経時的変化はみられず，逆に治療が奏効して改善傾向を示す症例もあった．以上より，消化管アミロイドーシスの内視鏡所見は多彩であり，その沈着程度とは必ずしも相関しないこと，進行は比較的緩徐であることが示唆された．

　We investigated endoscopic and pathological features of upper gastrointestinal lesions in 46 patients with amyloidosis. Endoscopic findings of gastric lesions were characterized by submucosal protrusions in the AL-type amyloidosis, and fine granular elevations or multiple nodular protrusions in the AA-type amyloidosis. Duodenal lesions of the AL-type were frequently recognized as multiple submucosal protrusions, in 50％ of patients with slight amyloid deposition. Although fine granular elevations were frequently observed in the duodenum of patients with AA-type amyloidosis, endoscopic abnormalities were not observed in some patients with marked amyloid deposition. Endoscopic and histological findings of the duodenal lesions were static in approximately half the patients with amyloidosis. In addition, some duodenal lesions improved with treatment of the primary disease. Our findings suggest that upper gastrointestinal amyloidosis presents various endoscopic findings, regardless of the degree of amyloid deposition, and it progresses slowly.