Unusual patterns of Histoplasma capsulatum meningitis and progressive multifocal leukoencephalopathy in a patient with the acquired immunodeficiency virus.

Disseminated histoplasmosis (DH) and progressive multifocal leukoencephalopathy occur in acquired immunodeficiency syndrome (AIDS). At autopsy, DH patients with central nervous system involvement almost always show extensive involvement of the lungs and reticuloendothelial system in addition to the brain, and progressive multifocal leukoencephalopathy is manifest as multiple demyelinating lesions in several locations in the brain. We describe an AIDS patient with a long history of aggressively treated DH who died with DH in the brain only; fungus was not found elsewhere at autopsy. In addition, there was a papovavirus infection restricted to the cerebellum with predominant involvement of the internal granular cell layer; again, demyelinating lesions were not found elsewhere in the brain. Each of these patterns of brain involvement is rare. As the incidence of AIDS increases and patients are treated aggressively, the frequency of unusual neuropathologic patterns of opportunistic infections may be expected to increase.