左前頭葉Neurocytomaの1例

Neurocytoma in the Left Frontal Lobe

I．はじめに

　Neurocytomaは最近認識されてきた神経細胞系腫瘍であるが^4），脳室内に認められることが多く^3,5），大脳半球に発生したという報告は少ない^8）．今回，われわれは発育緩徐な大脳半球の腫瘍性病変が電顕的検索によりneurocytomaと判明した1例を経験した．また，本腫瘍は左大脳半球のBrodmann44野を含んで存在していたため，術前に言語中枢の局在と言語機能の代償性についても検討した．

We report a case of a 7-year-old right-handed girl with neurocytoma in the left frontal lobe. She de-veloped convulsive seizures on the right side of her face at the age of 1 year and 8 months, and CT scan re-vealed a low density lesion in the left frontal lobe near the Sylvian fissure. CT scan at the age of 7 years showed slight enlargement of the lesion in size, and linear calcification in the mass. MRI imaging revealed the lesion to be a solid mass involving the area of Brod-mann 44 of the left cerebral hemisphere. However, amytal test disclosed that her speech center was not situated in the left cerebral hemisphere. Subtotal re-moval of the tumor and removal of the epileptogenic focus were performed and no neurological deficits in-cluding speech disturbance resulted.

The tumor was diagnosed as neurocytoma by elec-tron microscopy. Because this tumor was considered of low malignancy, no radiation or chemotherapy was given. It is emphasized that neurocytoma can occur in parts of the brain other than in the ventricular system, though the incidence of the tumor is more frequent in the latter.