第2頚椎に発生した骨原発性悪性リンパ腫の1例

Primary Malignant Lymphoma of the Axis : Case Report

　抄録：骨原発性悪性リンパ腫はnon-Hodgkinリンパ腫の2.6％，原発性骨悪性腫瘍の5％以下で極めて稀な疾患であるが，その内，頚椎原発は2％以下である．症例は52歳，男性．急速に増悪する強い頚部痛を主訴に来院した．精査の結果，第2頚椎病的骨折の診断で生検術と後方固定術を施行した．術中迅速診断はmalignant fibrous histiocytomaであったため，腫瘍は第2頚椎の椎弓，棘突起を含め後方部のみを一塊として摘出し，C0～C6の範囲で後方固定術を施行した．しかし，術後病理組織診断は悪性リンパ腫であった．そのため化学療法，放射線療法を施行し，現在は完全寛解状態である．当疾患は極めて稀で，しかも画像上で特異的な所見はなく，病理組織学的にも診断困難な場合が多い．しかし，早期に治療を行えば比較的予後は良好なため，診療の際は当疾患も念頭において診断，治療にあたる必要があると考えられた．

　Primary malignant lymphoma of bone is rare disease that accounts for only 2.6％of non-Hodgkin's lymphoms and less than 5％of primary malignant bone tumors, and malignant lymphoms originating in the cervical spine represent less than 2％of primary malignant lymphoms of bone.

　A 52-year-old man with severe neck pain of 3 weeks duration came to our department on May 7,2001. There was no history of trauma or systemic disease. Plain radiographs and an MRI scan revealed involvement of almost the entire axis by tumor and a pathological fracture of tha odontoid process. Whole body CAT and bone scans showed no other skeletal involvement by tumor. At surgery, a frozen section of the tumor was diagnosed as malignant fibrous histiocytoma, and we resected the dorsal portion of the tumor, including the lamina and spinous process of C2, and stabilized C0-C6 with a titanium rod and wire system. The postoperative pathological diagnosis was malignant lymphoma, and the patient was treated with chemotherapy and irradiation. One year postoperatively there was no evidence of recurrence of the tumor.

　The radiological and histological features of primary bone lymphoma are non-specific, often making the diagnosis difficult. Because early diagnosis and appropriate treament with a combination of surgery, radiation therapy, and chemotherapy can result in a relatively good outcome, recognition of this rare tumor is important.