Extradural hematoma complicating middle fossa arachnoid cyst.

Two cases of post-traumatic extradural hematoma complicating an arachnoid cyst of the middle cranial fossa in children are described. While subdural and intracystic hemorrhages are well-known complications from this malformation, the association with extradural hematoma has never been previously reported in the literature. The pathogenetic mechanisms are discussed and the particular vulnerability of intracranial arachnoid cysts is stressed.