原発性空腸癌の1例

Primary Carcinoma of the Jejunum

　小腸は全消化管の90％以上の面積を占めるとされている割に，ここから発生する悪性腫瘍は極めて少ない．その理由として，内容停滞時間の短い点，細菌の少ない点，アルカリ性である点，粘膜の細胞増殖の速やかな点，ミクロゾームエンザイムによる発癌剤解毒作用の点，局所の免疫学的な点などが挙げられている．今回われわれは空腸癌の1例を経験したので報告する．

　A 47-year-old man was admitted to Ashikaga Red Cross Hospital complaining of nausea and an abdominal mass. He noticed nausea three months prior to admission and a tender abdominal mass in his right abdomen half a month before admission. On laboratory investigation, neither anemia nor jaundice was seen. CEA was 1.95ng/dl and α-fetoprotein was negative. Roentgen examination of the small bowel revealed a huge circumferential ulcer at the upper jejunum. There was no stenosis at the ulcer site but rather an aneurysmal dilatation of the lumen was seen, which was considered to be a characteristic finding of a malignant lymphoma of the small intestine. Intraoperative endoscopy showed a deep demarcated ulcer. The tumor was located at the upper jejunum which was about 60cm distal to the Treitz ligament and fixed to the ileum end and the ascending colon. Partial resection of the jejunum and right hemicolectomy were performed. Histological examination of the resected specimen revealed a poorly differentiated adenocarcinoma from mucosa to serosa of the jejunum. There was no invasion to the ileum end and the colon. No metastasis was present in the regional lymph nodes.