Introduction: Arachnoid cysts are believed to account for about 1% of all intracranial expansive lesions, some remain inactive throughout life, others lie dormant for many years before clinical manifestation. In a few cases, arachnoid cysts have ruptured after cranial trauma or more rarely, spontaneously, with resultant subdural haemorrhage or CSF collection.
Case report: We report three cases with traumatic rupture of arachnoid cyst into the subdural space in children, which is an extremely unusual complication.
Discussion: A review of the literature revealed only 18 previously reported cases.