RESUMO
BACKGROUND: Cerebral arteriovenous malformations (AVMs) have been commonly regarded as congenital. However, this suspected origin has been challenged by reports of de novo cerebral AVM. CASE DESCRIPTION: We have described a 25-year-old man without any known history of cerebrovascular disease, in whom cranial imaging demonstrated the de novo appearance of a pial AVM. Initial magnetic resonance imaging at 11 years of age had revealed the presence of a 2-cm parafalcine arachnoid cyst. Computed tomography and magnetic resonance imaging performed 14 years later showed a new cerebral AVM in the left frontal lobe, which was then confirmed angiographically. CONCLUSIONS: The findings from our case report and from 9 similar reports challenge the traditional theory that AVMs constitute congenital lesions.
