延髄嚢胞性血管芽腫の1例

A case of cystic hemangioblastoma of the medulla oblongata

I．はじめに

　血管芽腫はおもに後頭蓋窩に好発する腫瘍で，小脳では壁在結節を伴う嚢胞性腫瘍が多い^{3,9,12,13,16）}．しかし脳幹部にみられる場合おもに延髄背側正中部で実質性のものであり^6,8,12,14），摘出術においては技術的にも非常な困難を伴い，手術死亡率も高く，悲惨な結果に終ることが多い．しかし血管芽腫であれ星細胞腫であれ脳幹部に嚢胞を伴う腫瘍の報告はきわめてすくない^{1,2,7,9,16,17）}．今回われわれは壁在結節を伴う延髄嚢胞性血管芽腫の非常にまれな症例を経験したので，文献的考察を加え報告する．

Cystic hemangioblastoma of the brain stem is an ex-tremely rare clinical entity. Only eight cases have been reported in the literature.

This is a report of a case of successful extirpation of a cystic hemangioblastoma of the medulla oblongata. A 47-year-old man was admitted to our clinic with the complaint of progressive numbness on his left upperlimb since January 1995. Neurological examination re-vealed numbness and decreased vibration sensation on his left upper limb. MRI showed a cystic 1.5×2.0cm le-sion on the medulla oblongata, and with administration of Gd-DTPA, a small mass lesion on the dorsolateral side of the medulla oblongata. Left vertebral angiogram revealed a tumor fed directly from the left vertebral artery. An operation was performed using a suboccipit-al approach.

The dorsal surface of the medulla was swollen ede-matously, suggesting the site of a cyst, which emptied by means of opening the wall. The reddish tumor was embedded on the left dorsolateral surface of the medul-la oblongate. A total extirpation of the tumor was car-ried out under microscopic procedure. Histologically, the tumor was diagnosed as a hemangioblastoma. The patient was free from his distressing numbness im-mediately after the operation, and discharged without neurological deficit.