This can rupture and cause a spreading cerebritis or rupture into a ventricle producing ventriculitis or meningitis. Microscopically, the abscess has a center full of necrotic debris, neutrophils, macrophages and organisms. The second layer about this is made up of proliferating fibroblasts and capillaries with a more chronic inflammatory reaction. The third layer is of reactive astrocytes with plump pink cytoplasm as well as chronic inflammatory cells such as lymphocytes and plasma cells. The intraparenchymal, subdural, or epidural abscess acts as a mass lesion and can cause cerebral edema and herniation, along with neurological signs such as a hemiparesis, seizures, or other signs depending on where it is localized.
Herniation can lead to death as can rupture of the abcess into ventricles and meninges.
Poirer J et.al. Manual of basic neuropathology. Medline will open in a new window.