Primary nervous system lymphoma.

Primary nervous system lymphoma (PNSL) is a rare type of non-Hodgkin's lymphoma confined to the nervous system. Although significant progress has been made in the treatment of PNSL over the past decade, patients with this disease are rarely cured. Until recently, whole brain radiation therapy has been the standard treatment for PNSL. However, whole brain radiation therapy is associated with a high relapse rate and late neurotoxicity after chemotherapy, especially in patients older than 60 years of age. Methotrexate-based chemotherapy has become the standard approach to treat patients with newly diagnosed PNSL. Ongoing research efforts are focused on identifying chemotherapeutic agents with good antilymphoma activity that penetrate the blood-brain barrier. The roles of intrathecal chemotherapy and blood-brain barrier disruption are not fully defined. Given the rarity of this tumor, patients with PNSL should be referred to tertiary cancer centers where ongoing clinical trials are underway to identify the optimal treatment of PNSL.