How I Treat How I treat CNS lymphomas

Central nervous system (CNS) involvement of non-Hodgkin lymphoma (NHL) occurs in 2 patterns: (1) primary CNS lymphoma (PCNSL), which is limited to the brain parenchyma, intraocular compartment, cranial nerves, leptomeninges, and, rarely, spinal cord; and (2) secondary CNS lymphoma (SCNSL), in which there is concomitant systemic, and CNS localization of lymphoma, often within the leptomeningeal compartment. PCNSL is a rare brain tumorwith an annual incidence in theUnited States of approximately 1900 new cases each year. Although PCNSL constitutes approximately 3% of all newly diagnosed brain tumors, and 2% to 3%of all cases ofNHL, the Surveillance, Epidemiology and End Results (SEER) database suggests that the incidence of this neoplasm may be increasing among patients age 65 and older, with patients older than 75 having the highest incidental risk. Because the CNS complications of NHL are relatively rare, there is limited prospective and/or randomized data to guide its therapy. Historically, CNS lymphomas have been associated with a very poor prognosis. On the other hand, an accumulation of recent prospective phase 1/2 results, as well as retrospective series, demonstrate reproducible improvements in outcomes for patients with PCNSL and SCNSL. Because published evidence for therapeutic advances may not be uniformly reflected in population-based data, there is a possibility that patients in the community may not routinely receive optimal therapy. Our goal in this review is to highlight areas of progress and to provide an overview of current knowledge regarding the pathogenesis of PCNSLs and SCNSLs. In addition, we will illuminate strategies we believe to be most effective in establishing diagnosis and staging, as well as in therapeutic management.