第3腰椎椎体に発生した血管肉腫の1例

Angiosarcoma in Lumbar Spine : Case Report

　抄録：血管肉腫は血管の内皮細胞を由来する軟部組織腫瘍であり，椎体からの発生は極めて稀である．第3腰椎に発生した血管肉腫の手術例を経験したので報告する．症例は37歳の男性で，腰痛と左下肢痛を主訴に来院した．X線像，CT，MRIなどから第3腰椎椎体から第2腰椎辺縁まで広がった腫瘍が認められたため，前後合併による第3腰椎の椎体切除術を施行した．術後の病理組織所見にて，異型性の強い腫瘍細胞が未熟な血管腔を形成し，免疫染色ではFactor-8，CD-34のそれぞれで腫瘍細胞が染まったため，血管肉腫と診断された．血管肉腫は，5年生存率6～8％と悪性度の高い腫瘍である．術後約1カ月よりインターロイキン2による化学療法を2週間行い，これを1クールとして6週間ごとに投与を行った．軽度の白血球減少を認めたが，術後2年6カ月の現在，腫瘍の再発はみられず現職に復帰している．

　Angiosarcoma is rarely found in the lumbar spine. It is a tumor of soft tissue that originates from the endothelial cells of blood vessels. In this article, we report a case of angiosarcoma that was located in the third lumbar vertebra. A 37-year-old man with low back pain and left unilateral leg pain was diagnosed with a tumor of the third lumbar vertebra based on the X-ray, computed tomography (CT), and magnetic resonance imaging (MRI). We suspected that the tumor was an aggressive benign tumor, and performed a total spondylectomy of the third lumbar vertebra. The pathological diagnosis was angiosarcoma post operationally because resected tissue stained by Factor-8 and CD-34 (immune stain) showed malignant cells around blood vessels. Angiosarcoma is a high malignancy tumor, and the 5-year survival rate is 6～8％.

　We prescribed interleukin-2 (IL-2) for 2 weeks, starting 1month after surgery. Additionally we prescribed IL-2 for 5 two-week treatments, each followed by 6 weeks off. IL-2 inhibits the growth of angiosarcoma by vitalizing NK cells, killer T cells and LAK cells. Although IL-2 slightly decreased the patient's WBC counts, he has not had any recurrence of the angiosarcoma as of 30months after surgery, and he has returned to work.