Arachnoid cyst rupture with subdural hygroma: report of three cases and literature review.

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.