出血で発症した脳内hemangioendotheliomaの1例

Hemangioendothelioma of the Brain Presenting with Intracerebral Hemorrhage : A Case Report

要旨　Hemangioendothelioma（HE）は血管より発生する内皮性腫瘍であり，血管腫と血管肉腫との中間型の低悪性度，もしくは中間悪性度とされ，WeissとEnzingerによって1982年に初めて提唱された。今回，出血で発症した脳内HEを経験したため，その特徴について文献的考察を加えて報告する。症例は51歳の女性で，一過性の視野障害と左上肢の脱力を主訴に当院を受診した。頭部CTで右頭頂葉に3 cm大の不均一な高吸収域を認め，同病変はMRI T1強調画像で高信号，T2強調画像で等信号，T2^＊強調画像では著しい低信号であり，明らかな造影効果は認めなかった。海綿状血管腫の術前診断のもと，開頭腫瘍摘出術を施行した。病理診断は出血を伴ったHEであった。

Hemangioendothelioma （HE） is an uncommon vascular tumor that is intermediate in histological appearance between a hemangioma and an angiosarcoma. Presently, it is regarded as endothelial tumors of low-grade or intermediate malignancy. It has been reported in the liver, lung, heart, mediastinum, lymph nodes, extremity, and bone. The occurrence in the brain is extremely rare ; only 16 cases have so far been reported. We report a 51-year-old woman who presented with transient visual disturbance and weakness of the left upper limb on April 12th 2003. Computed tomography （CT） revealed a high density mass in the right parietal lobe. In magnetic resonance imaging （MRI）, the lesion is hyperintense on T1WI, isointense on T2WI, and no enhancement with gadopentetate dimegliumine. Intratumoral hemorrhage was indicated and preoperative diagnosis was cavernous angioma. The tumor was excised completely on April 28th 2003. Pathologically, the tumor cells resembled endothelial cells, positive immunoreactivity for Factor VIII, and grew in small nests or cords. Postoperative MRI showed complete removal of the tumor. There has been no recurrence for 8 months after the surgery, but we have to follow MRI up for a long time. We discussed intracerebral HE clinically and neuroradiologically.

（Received : February 18, 2005）