Simultaneous typical and extraordinary imaging findings of AIDS-associated cytomegalovirus encephalitis

Encephalitis caused by cytomegalovirus (CMV) is a devastating disease that occurs mostly in profoundly immunocompromised individuals, particularly in the setting of advanced HIV infection or organ transplantation. Imaging findings in AIDS-associated cytomegalovirus encephalitis that have been described range from ventriculitis (more common) to solitary mass lesions (less common). We describe a fatal case of AIDS-associated cytomegalovirus encephalitis that included typical imaging findings but also atypical features with widespread, multifocal lesions demonstrating restricted diffusion on magnetic resonance imaging (MRI). It is likely that these diffusion abnormalities are appreciated due to changes in imaging technology from the pre-highly active antiretroviral therapy era in which the typical imaging findings of CMV encephalitis were first described. The differential diagnosis of widespread, multifocal lesions with restricted diffusion in the setting of AIDS should now include CMV encephalitis.