Relapse of primary central nervous system lymphoma 13 years after high-dose methotrexate-based polychemotherapy.

We report a now 74-year-old patient who was successfully treated with a methotrexate (MTX)-ssbased polychemotherapy protocol (Bonn protocol) for primary central nervous system lymphoma (PCNSL) in 1996. When presenting with an unusually late relapse after 13 years of tumor-free survival the diagnosis was made on the basis of clinical and radiological criteria. In the context of the very limited treatment options for recurrent PCNSL, it is reassuring that the re-application of high dose-MTX-based polychemotherapy, including intraventricular treatment, again succeeded in a sustained complete response with still low neurotoxicity.