Intracranial arachnoid cyst with subdural hematoma

A case of a middle fossa arachnoid cyst associated with a post-traumatic subdural hematoma is reported, where the inner membrane of the hematoma did not entirely cover the cyst surface. At operation a third cavity was detected between the arachnoid cyst and the hematoma and it is postulated that the subdural hematoma was consequent to the developmental anomaly. We have reviewed 72 cases in the literature and discuss the management of subdural hematoma in the presence of arachnoid cysts.