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 incidence of PCNSL has been increasing since the seventies in immunocompetent patients. The main increase, however, is taking place since the mid-eighties 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 renal, and 2–7% for cardiac, lung or liver transplant recipients. Patients with congenital immune deficiency have a risk of 4%. PCNSL may also present as a secondary malignancy.