What causes PCNSL?

What causes PCNSL?
Little solid evidence as to a single cause or method of infection exists to explain why this disease exists.   The most consistent contributing factor is a weakened immune system whether from disease (AIDS, Lupas, Hepatitis. etc) or medically (organ transplant, treatment of autoimmune disorders). This population is considered "immunocompromised" and reflects the majority of PCNSL patients however it is also showing up in patients with healthy immune systems.
Importantly, the incidence of PCNSL in the immune competent population has been reported to have increased more than 10-fold from 2.5 cases to 30 cases per 10 million population over the loast 20 years.The cause for the increase in incidence of this disease in the immune population is unknown.  It may be an environmental issue or simply more accurate diagnosis.
There has been some question as to whether the “Epstein-Barr virus (EBV)” responsible for Mononucleosis is a contributing factor.  EBV has shown up in pathology studies of PCNSL tumors but people whom show no sign of EBV have still contracted PCNSL.  The Jury also still remains hung on whether cell phone usage causes brain tumors.
Age is a significant contributing factor. PCNSL most often shows up in persons in their 50’s or 60’

In summary:
Primary Central Nervous System Lymphoma is an opportunistic disease that often occurs in people with weakened immune systems but it is also increasingly occurring in healthy people with no known immune deficiencies.  There is no single contributing factor or cause for this disease