Primary brain tumors in the acquired immunodeficiency syndrome

Primary central nervous system lymphoma occurs in about 10% of patients with the acquired immunodeficiency syndrome, and is the most common brain tumor in this population. Patients present with an altered mental status and lateralizing signs. Computed tomography or magnetic resonance scan usually demonstrates single or multiple contrast-enhancing masses which are indistinguishable from toxoplasmosis or other central nervous system processes. Brain biopsy or possibly the demonstration of Epstein-Barr viral DNA in the cerebrospinal fluid are the only definitive means of diagnosis. Cranial irradiation has been the cornerstone of therapy, producing regression of tumor in most patients; however, median survival is only a few months. Recent experience of combining chemotherapy with radiotherapy suggests that a subgroup of patients can benefit from this approach, with survival reaching 1-2 years.