Erroneous diagnosis within the cranial vault.

The majority of pediatric neoplasias of the brain are midline growths in the posterior fossa. These mass lesions lead to obstruction of cerebrospinal fluid circulation and cause increased intracranial pressure. Affected children typically present with insidious complaints of headache and vomiting. Ataxia, cranial nerve palsies, or pyramidal tract signs may be present at the time the diagnosis is entertained. In the reports describing pathognomonic clinical features of posterior fossa tumors, an accelerated presentation with minimal prodromal events has not been emphasized. This report details the case of a child with a cerebellar medulloblastoma who presented with abrupt onset of fever, nuchal rigidity, and altered mental status. Emergency department misdiagnosis occurred.