Update on the management of primary CNS lymphoma

Primary central nervous system (CNS) lymphoma is a non-Hodgkin's lymphoma r estricted to the nervous system. The incidence of this lymphoma is rising i n the immunocompetent population but may be decreasing in patients with the acquired immune deficiency syndrome (AIDS) due to the introduction of high ly active antiretroviral therapy. A periventricular, diffusely enhancing le sion on magnetic resonance imaging (MRI) is suggestive of primary CNS lymph oma, but a stereotactic biopsy is needed to make a definitive diagnosis. Co ncurrent leptomeningeal and ocular involvement is common in this brain tumo r. Because primary CNS lymphoma is exquisitely sensitive to steroids, these drugs should be withheld until tissue is obtained for diagnosis. Age and p erformance status are important prognostic factors, regardless of specific treatment. Methotrexate in high doses is the single most effective chemothe rapeutic agent for primary CNS lymphoma. It substantially improves survival when combined with radiation therapy and is better than radiotherapy alone as a single agent. Multimodality treatment results in delayed cognitive ne urotoxicity, particularly in older patients, New treatment protocols have f ocused on the use of chemotherapy alone.