Presentation
Known HIV+ patient with altered mental state.
Patient Data
Non-specific findings of juxtacortical (subcortical U-fibers) white matter T2/FLAIR hyperintensities involving the precentral gyri at the upper convexity. There are similar hyperintensities in the right thalamic/posterior arm of the internal capsule.
Case Discussion
These findings are non-specific, but in an HIV+ patient, PML is not excluded. The main differential diagnosis would be HIV encephalitis, CMV encephalitis, IRIS (Immune Reconstitution Inflammatory Syndrome), ADEM & multiple sclerosis.
This case is atypical as the findings are not as extensive as expected in PML. The patient died a few months later. This patient had a prior brain biopsy which confirmed JC virus-infected oligodendrocytes with enlarged amphophilic nuclei located at the periphery of the lesions.
Other pathologic findings include :
- reactive gliosis with enlarged astrocytes
- macrophages containing phagocytosed cellular debris and myelin