Successful treatment with adapted high dose methotrexate in a hemodialysis patient with primary central nervous system lymphoma: 100mg/m2 seems sufficient.

High dose methotrexate (HD-MTX) based chemoimmunotherapy is a central part of the standard approach to treatment of primary central nervous system lymphoma (PCNSL). Renal dysfunction leads to delayed MTX complete elimination and critical MTX concentration. Despite the recommendations, hemodialysis status should not exclude HD-MTX. We report the case of a 64 years old woman on chronic hemodialysis with PCNSL successfully treated with HD-MTX-based chemoimmunotherapy with an adjusted dose of 100mg/m2, instead of the usual dose of 3500mg/m2, and daily hemodialysis started 24h later. The patient had no significant toxicity and was in complete remission at 1 year after the end of the treatment. We argue that ESRD is not an absolute pitfall to the use of HD-MTX for hematological malignancies. Experts should consider the use of adjusted dose at 100mg/m2 as a viable therapeutic modality in ESRD patients.