In HIV CNS lesions can be divided into those which exhibit mass effect and those that do not.

CNS lesions with mass effect include:

  • toxoplasma encephalitis
  • primary CNS lymphoma
  • tuberculoma (more common in the developing world)
  • other lesions are less common but include brain abscesses secondary to Staphylococcus, Streptococcus, Salmonella, Aspergillus, Nocardia, Listeria & Cryptococcus

    toxoplasmosis and primary CNS lymphoma are the most common

    CNS lesions without mass effect are commonly due to:

  • progressive multifocal encephalopathy, or
  • HIV-associated encephalitis