小腸に腫瘤を形成した原発性消化管アミロイドーシスの1例

Primary Intestinal Amyloidosis with Tumor Formation in the Small Intestine, Report of a Case

要旨　患者は56歳，男性．繰り返す上腹部痛と嘔吐を主訴として入院した．小腸X線検査では，大小の粘膜下腫瘍様の隆起病変が空腸に多発していた．小腸内視鏡検査にて十二指腸から空腸にかけ黄色調の隆起病変の多発を認めた．隆起病変からの生検では，粘膜下層を中心に多量のアミロイドの沈着が認められた．隆起病変による重積症状の改善を目的として手術を施行した．術中ファイバーを施行し，狭窄を認める部分の切除を行った．切除標本には大小の腫瘤の多発および皺襞の肥厚を認めた．病理組織学的には，すべての腫瘤，肥厚した皺襞に粘膜下層を中心に多量のアミロイド沈着を認めた．検索の結果，横行結腸にもアミロイドの沈着を認めたが，胃，直腸，肝臓，腎臓には組織学的にアミロイド沈着は認めなかった．本症例は基礎疾患を欠き原発性消化管アミロイドーシスと思われた．本症例のごとく，小腸に腫瘤を形成するアミロイドーシスはまれであった．

　A 56-year-old man was admitted to Fukuoka University Hospital with the complaints of recurrent upper abdominal pain and vomiting. Barium meal study of the small intestine revealed multiple polypoid lesions and thickened folds. Double contrast study of the small intestine showed polypoid lesions in the jejunum ; however, there was no rigidity with distensibility being kept well.

　Endoscopy of the small intestine revealed multiple yellowish polypoid lesions in the duodenum and jejunum. The biopsy specimen from these lesions revealed massive deposition of amyloid in the submucosa.

　Later, intussusception developed, which necessitated laparotomy.

　Intraoperative endoscopy revealed polypoid lesion with ulceration and bleeding as well as concentric stenosis in the jejunum.

　Partial resection of the jejunum, including these lesions, was performed. Multiple tumors and thickened folds were found in the resected specimen. Histologically, these lesions were caused by massive amyloid deposition mainly in the submucosal layer.

　In further examination amyloid deposition was also recognized in the biopsy specimen from erosions of the transverse colon. No deposition was found in the stomach, rectum, liver and kidney.

　Since no predisposing disorders were recognized, and the diagnosis of primary intestinal amyloidosis was established.

　Tumor forming amyloidosis was rare in the intestinal tract.