Figure 2.

Demyelinating lesions of progressive multifocal leukoencephalopathy (PML) may be circumscribed within the grey matter (GM). (A) A single round lesion is present in GM of an HIV-negative PML patient (arrows) and contains JCV-infected cells. Double immunohistochemistry (IHC) for JCV T antigen (Ag) (v-300, dark blue) and MAP-2 (M-4403, brown). The region corresponding to the panel is highlighted at lower magnification by the square box in the inset, demonstrating the absence of demyelination in the nearby white matter (WM) (H&E/Luxol fast blue). (B) An extensive coalescent area of tissue destruction restricted to the GM (arrow) is located at a distance from an affected area in GWJ. Double IHC for JCV T Ag (v-300, red) and MAP-2 (M-4403, brown). The boxed area in the inset shows JCV-infected cells (arrows). Scale bars: 1 mm.