45 year old San Diegan fisherman with 1 week history of bizarre behavior. The most likely etiology of this process is: <image 1>
['Creutzfeldt-Jakob disease', 'Amebic encephalitis', 'Herpes Simplex encephalitis', 'Progressive Multifocal Leukoencephalopathy (PML)', 'Subacute sclerosing Panencephalitis (SSPE)']
The slide demonstrates severe necrotic encephalitis with free-living amebae histologically difficult to distinguish from lipid-laden macrophages. CreutzfeldtJakob disease consists of a non-inflammatory spongiform encephalopathy. Herpes simplex virus encephalitis consists of subacute encephalitis with varying amounts of T-cells and polymorphonuclear cells with occasional neuroglial nuclei demonstrating Cowdry A-type inclusions. Progressive multifocal leukoencephalopathy is a white matter disease remarkable for the absence of Tcell or polymorphonuclear cell infiltrate and an abundance (sea of macrophages). Subacute sclerosing panencephalitis is subacute encephalitis characterized by abnormal nuclear inclusions in both neuronal and glial elements and is observed in individuals with measles infection approximately a year after initial presentation.