Fig 2.

Early microscopic pathologic features of reversible encephalopathy, hematoxylin-eosin stain. A, Hematoxylin- eosin–stained sections showed many small blood vessels with reactive endothelial cells (black arrow) in the white matter demonstrating cellular and nuclear enlargement as well as mild interstitial edema (white arrow). Some vessels appeared nonreactive and are visible as a comparison (arrowhead). No vasculitis, demyelination, or axonal swelling was seen. Some scattered erythrocytes are present from the biopsy procedure, but no hemosiderin-laden macrophages were seen. B, These reactive blood vessels were also present in the gray matter, seen adjacent to a neuron (arrow), along with reactive astrocytes (arrowheads).