Damek, Denise A.

PCNSLs in elderly persons are usually not mediated by Epstein Barr Virus (EBV), unlike PCNSLs in patients with AIDS or organ transplantation; hence IHC or ISH studies for EBV are not routinely performed. We have encountered patients 65 years or older who had autoimmune polyneuropathy (on CellCept for 3 years), polymyositis (oral prednisone alone for >15 years), rheumatoid arthritis (methotrexate >10 years), myasthenia gravis (azathioprine >10 years), or “senile immunosuppression” who developed multifocal, necrotic, EBV+ PCNSLs. Reducing or withdrawing immunosuppressive medications lead to recovery and regression of the PCNSL in some patients, but not all. The striking feature of this series is the variety of underlying diseases‐‐ and accompanying medications‐‐ that can be associated with EBV‐mediated PCNSLs in the elderly patient. Increased testing of PCNSLs for EBV by IHC or ISH may be warranted in any elderly person on any immunosuppressive medication.