Arachnoid cyst associated with subdural hematoma: report of three cases and review of the literature.

INTRODUCTION: Arachnoid cysts are usually found incidentally and are generally asymptomatic. They are thought to be developmental anomalies, and their etiology is unknown. Some complications such as subdural hematoma, subdural hygroma, and intracystic bleeding can occur after minor traumas. CASE REPORT: Here, we report three cases. Case 1 has subdural hematoma associated with subdural hygroma, case 2 has subdural hematoma after a birth delivery, and case 3 has intracystic bleeding associated with subdural hematoma. DISCUSSION: We suggest to treat the complicating event in our patients and have chosen burr-hole evacuation for treatment.