[Three cases of arachnoid cysts associated with chronic subdural hematoma (author's transl)].

The association of arachnoid cyst of the middle cranial fossa and subdural hematoma has been emphasized previously but is not common knowledge. We present three cases of arachnoid cyst of the middle cranial fossa and associated chronic subdural hematoma. The importance of computed tomography for the diagnosis of arachnoid cyst associated with the hematoma is emphasized. Pathogenesis of arachnoid cyst and the hematoma remain uncertain. However histological findings suggested that subdural CSF collection might be important to develop hemorrhagic outer membrane of the chronic subdural hematoma.