The rising incidence of PCNSL has allowed a greater understanding of the clinical features and behavior of this once rare tumor. Factors such as dissemination of tumor within the central nervous system, the presence of tumor behind an intact blood-brain barrier, as well as leptomeningeal and ocular involvement must be considered in the design of treatment protocols for this disease. The addition of chemotherapy has made a significant impact on the treatment of PCNSL, but the prognosis of PCNSL remains worse than for comparable systemic non-Hodgkin's lymphomas. With continued development of chemotherapy regimens, the hope is for improved survival without the need for potentially neurotoxic radiation therapy.
