Neovascularity, necrotic center, surrounded by reticular network. Collagen capsule, necrotic center, gliosis around capsule. Symptoms usually present for less than 2 weeks. Note that a fever is a poor diagnostic sign for brain abscess. Unchecked expansion of a brain abscess leads to death by herniation.
Blood cultures are usually negative.
CSF often shows non specific findings and therefore is of limited utility. Furthermore, obtaining CSF via LP carries the potential risk of herniation. Used for staging. The cerebritis phase is characterized by a low density area of necrosis surrounded by edema, and correlates well with the presence of pus. The amount of contrast enhancement and diffusion of contrast into central core may give clues as to age of abscess.