X線像上大きさ16mmであった直腸原発悪性リンパ腫の1例

Primary Malignant Lymphoma of the Rectum, Measuring 16 mm in Radiologic Size, Report of a Case

要旨　直腸原発の小さな限局型悪性リンパ腫の1例を経験した．患者は61歳，女性．症状はなかった．久保医院での大腸癌検診でポリープを指摘され，1994年1月21日当科初診．大腸内視鏡検査，注腸X線検査で上部直腸にX線像上大きさ16mmの粘膜下腫瘍を認めた．生検診断はMALTリンパ腫疑いであった．EUSでは第2層・第3層に限局する境界明瞭な低エコー腫瘤を認め，わずかな内部点状高エコーを混じていた．体表リンパ節および肝・脾を触知せず，また，末梢血液検査，胸部X線・CTでも異常を認めず，直腸に限局した原発性悪性リンパ腫を考え，EMRを施行した．切除標本では大きさ10mmのnon-Hodgkin・びまん型悪性リンパ腫と診断された．

　A 61-year-old female without complaints visited to our hospital on Jan. 21, 1994, because, at another clinic, a rectal polyp had been detected during screening for a rectal polyp by other clinician's colo-rectal cancer. Total colonoscopy and barium enema revealed a submucosal tumor, measuring 16 mm in radiologic size, in the upper rectum. Biopsy specimen through colonoscope suggested so-called MALT lymphoma. Endoscopic ultrasonography showed a circumscribed low echo mass with several internal slight high echo spots at the second and third layer of the rectal wall. Physical examination, hematology, chest radiologic examination, abdominal CT, upper gastrointestinal endoscopy and radiologic examination of the small intestine revealed no abnormalities. Therefore, we made a diagnosis of small early malignant lymphoma of the rectum. Histologically, a specimen of the endoscopic mucosal resection, measuring 10 mm in size, disclosed malignant lymphoma.