Extradural posttraumatic posterior fossa hematoma is a rare condition estimated to complicate about 0.3% of all craniocerebral injuries, and represents 4% to 12.9% of the entire group of extradural hematomas. Seven cases of posterior fossa extradural hematoma (PFEDH) are presented. There were four males and three females. One case occurred in an adult, the remaining six cases in patients 16 years of age or younger, two of whom were infants. In each case the hematoma resulted from a blow to the posterior part of the head. Each patient showed local evidence of trauma to the scalp, and a radiographic appearance of an occipital linear fracture crossing the path of the torcular Herophili or the transverse sinus. The clinical picture varied. Three patients suffered immediate transient unconsciousness. Three others suffered sudden respiratory arrest after a seemingly stable course of several hours in the hospital, but responded well to resuscitation maneuvers. Computerized tomography scans were obtained in three patients; in three others no specialized neurodiagnostic studies were feasible; in one patient, precise diagnostic documentation was achieved by Conray ventriculography. All seven patients were operated on and all survived. Two patients had associated surgical intracranial lesions: an underlying subdural hygroma of the posterior fossa in one, and a contralateral supratentorial temporal subdural hematoma in the other. Six patients have returned fully to their previous activities. One patient is steadily improving.

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Giant cell reparative granuloma (GCRG) is an uncommon nonneoplastic lesion of bone. It is even rarer in the bones of the skull, particularly in the calvarial bones. Originally considered to be peculiar to the jawbones, GCRG has been described in some other locations, such as the short tubular bones of the hand and the facial (paranasal) bones. Only one GCRG has been found in the skull, this one in the temporal bone. The authors were unable to find a report of such a lesion in the bones of the calvarium. The etiology of GCRG is unknown, but it is believed to result from a traumatic intraosseous hemorrhage or periosteal reaction. A GCRG was diagnosed in a 31-month-old male infant who presented with a nonpainful, slow-growing, right frontal swelling, apparently related to a head contusion that had occurred 21 months earlier. The lesion was removed surgically. The main differential diagnosis is giant cell tumor.

Diastematomyelia is rarely diagnosed in the adult. Only a few such cases have been reported in the literature. A 26-year-old Mexican man with lumbar diastematomyelia is reported who also harbored a T-12 intramedullary epidermoid tumor and an extradural teratoma located in the dorsal aspect of the dural sac opposite L-4. These three rare coincidental lesions were removed at surgery. The patient's condition improved.