Epidemiology of primary CNS lymphoma

In the beginning of the nineties the National Cancer Institute Surveillance , Epidemiology, and End Results Program calculated the incidence of primary central nervous system non-Hodgkin's lymphoma (PCNSL) as 1:100 000. The in cidence of PCNSL has been increasing since the seventies in immunocompetent patients. The main increase, however, is taking place since the mid-eighti es and is due to the increase of immunodeficieny and immunosuppression. The risk is 2-6% in AIDS patients according to clinical data and will probably further increase with the length of survival in these patients. Transplant patients carry a risk of 1-5% to develop a PCNSL. The risk is 1-2% for ren al, and 2-7% for cardiac, lung or liver transplant recipients. Patients wit h congenital immune deficiency have a risk of 4%. PCNSL may also present as a secondary malignancy.