ABSTRACT
The brain, eye, cerebrospinal fluid (CSF), and nerves are prone to invasion by primary extranodal Non-Hodgkin lymphoma (NHL). Primary central nervous system lymphoma (PCNSL) represents 2% to 3% of all primary brain tumors and a like number of extranodal NHL. The neurologic tumor, after increasing three-fold two decades ago, has remained stable in frequency in the last 10 years (1). Based upon data from the Central Brain Tumor Registry of the United States of America, up to 1200 new cases were expected during the year 2004 (2). In general, immunosuppression-or acquired immunodeficiency syndrome (AIDS)-related PCNSL afflicts younger patients (38 years) than immunocompetent patients (59 years); but many patients with PCNSL have experienced subtle forms of immunosuppression from cancer or connective tissue diseases, or have had prior therapy with corticosteroids or immunosuppressive agents. Although acquired and congenital immunodeficiencies precede PCNSL, the introduction of highly active antiretroviral therapy (HAART) has resulted in a declining incidence of disease (3,4).
Primary brain lymphoma, as a post-transplant lymphoproliferation (PTLD), arises in up to 7% of organ transplant recipients. The extent of immunosuppression is the major risk factor. Risk is lowest in recipients of renal allografts. As for systemic PTLD, the majority of cases is associated with infection by the Ebstein-Barr virus (EBV) and occurs within 6 to 10 months after transplantation. In 20% of patients, EBV infection is absent. EBV-negative PTLD tends to occur later (four to five years after transplantation) (5).
