Typical Light Microscopic Findings:
Acute: Widespread endothelial cell degeneration, hemorrhage and infarction; encephalitis with perivascular cuffing, focal necrosis, microgliosis; progressive lymphoid depletion; necrosis of intestinal mucosa
Chronic: glomerulonephritis, calcification of cartilagenous cells of ribs
Nonpurulent meningoencephalitis
In utero: widespread lymphoid depletion and thymic atrophy