下血を主訴とし多彩な消化管病変を認めた原発性アミロイドーシスの1例

Primary Amyloidosis with Variform Lesions in the Gastrointestinal Tract, Report of a Case

要旨　患者は56歳，男性で，下血，下腿浮腫，労作時呼吸困難を主訴に来院した．胸部X線写真上，両下肺野に微細顆粒状陰影，軽度の胸水および心拡大を認めた．また尿蛋白は陽性であった．注腸造影では直腸S状結腸移行部に腸管狭小化と不整な粘膜面を認め，内視鏡にて縦走潰瘍，不整潰瘍，粘膜出血斑，血腫が観察された．胃十二指腸造影では，球部に散在する小隆起を示し，内視鏡で，小隆起に加え粗糙な粘膜面と出血斑が観察された．胃，十二指腸，直腸よりの生検組織にアミロイド沈着が確認され，基礎疾患を認めず，過マンガン酸カリ処理抵抗性のCongo-Red染色所見より，原発性アミロイドーシスと診断された．

　A 58 year-old man was admitted to our hospital because of hematochezia, pretibial edema, and exertional dyspnea. Chest x-ray examination revealed cardiomegaly, pleural effusion, and micronodular shadow in both lower lung fields (Fig. 1). Proteinuria was also found. Barium enema examination revealed narrowing and irregular mucosal ulcerations in the rectosigmoid junction simulating ischemic colitis (Fig. 2 a). Colonoscopic examination showed various lesions ; longitudinal and irregular ulcers, and purpuric hemorrhagic and blackish raised mucosal areas which were thought to represent hematoma (Fig. 3 a - e). X-ray and endoscopic examinations of the duodenal bulb showed small nodules and mucosal purpuric hemorrhage (Fig. 2 b, 4 a, b). Biopsies of the rectum, duodenal cap, and stomach showed amyloid deposition (Fig. 5 a, b). The patient was diagnosed as having primary amyloidosis (AL), because there was no underlying disease and histochemically detected amyloid was resistant to potassium permanganate and did not react with anti-AA and antiprealbumine antibodies. The treatment by predonine and DMSO (dimethyl sulfoxide) was not effective. Six months later he died suddenly due to heart failure. Autopsy confirmed primary amyloidosis with generalized involvement.