Granulomatous amebic encephalitis presenting as a cerebral mass lesion.

Clinical and brain biopsy or autopsy findings in six patients with Granulomatous Amebic Encephalitis (GAE) due to acanthamoeba sp. were characterized by focal neurological symptoms, increased intracranial pressure, and focal neuroradiological findings. Craniotomies were performed because of the diagnostic possibility of a mass lesion such as a brain tumor or abscess. In four patients, frozen sections demonstrated free-living amebas. GAE may present as an acute or subacute intracerebral mass lesion with signs and symptoms of focal brain disease and should be differentiated from viral, bacterial, fungal, and other protozoal encephalitides.