Progressive multifocal leukoencephalopathy immune reconstitution inflammatory syndrome
Presentation
Patient presented with recent diagnosis of melanoma. On work up found to have lesion in brain on PET and also found to be HIV positive.
Patient Data
Ill-defined area of T2 change within the right frontal lobe extending to involve the subcortical U fibers and extension into the corpus callosum. Ill-defined patchy edge enhancement.
Case Discussion
CD4 count was noted to be very low. Patient was started on antiretroviral therapy (ART).
Biopsy - infiltration by mononuclear cells including lymphocytes, microglia, histiocytes and plasma cells. Associated gliosis as well as scattered astrocytes and oligodendrocytes with 'ground-glass' nuclear change. There is evidence of myelin degeneration. Many vessels show vasculitic changes.
The inflammatory infiltrate consists predominantly of CD2+/Cd3+ T-cells with moderate numbers of CD20+ B-cells. Appearances are consistent with PML with associated IRIS.