抄録
An occult arteriovenous malformation (AVM) in the septal region occurred in a 14-year-old boy, manifesting as headache and vomiting. Computed tomography showed a high-density mass in the septal region, faintly enhanced postcontrast. Mild hydrocephalus was also seen. Angiography revealed no abnormalities other than hydrocephalic signs. The lesion was totally removed by the transventricular approach after corticotomy of the left frontal lobe. The histological diagnosis was AVM. He was discharged without neurological or endocrinological deficits.