High-dose chemotherapy and stem cell transplantation for primary CNS lymphoma

The treatment of patients with CNS lymphoma has posed a challenge since this entity was first described. Several issues have complicated the management of these patients. First, it is important to define whether the lymphoma is confined to the CNS (primary CNS lymphoma, PCNSL) or whether there is co-existent or pre-existent systemic lymphoma (stage IV or secondary CNS lymphoma, respectively). Second, it is important to define the histological subtypes of lymphoma involving the CNS since multiple histologies are known to occur in the CNS and the treatment can vary depending on the histology.