Extradural hematoma complicating arachnoid cyst--case report.

A 37-year-old man is reported with post-traumatic extradural hematoma complicating an arachnoid cyst in the middle cranial fossa. While subdural and intracystic hemorrhages are well-known complications from this malformation, the association with extradural hematoma has only been reported in three cases in the literature. We describe a case occurring after head injury and discuss the etiology and treatment.