Primary cerebral lymphoma (Primary CNS Lymphoma, PCNSL) is an aggressive non-Hodgkin lymphoma that originates in the central nervous system without evidence of lymphoma in any other localization at the time of diagnosis. Primary cerebral lymphomas are less well-known and are characterized than their homologues the systemic lymphomas, as they are an entity whose frequency was scarce until a few decades ago. However, the great rise in incidence that this pathology has undergone over the last three decades, and which is still unexplained, makes more studies necessary to better understand the etiopathology of this entity. Thanks to the new systems of treatment, the prognosis of this pathology has improved significantly in recent years. Nonetheless, treatment of primary cerebral lymphoma continues to give rise to numerous controversies at present due to its high neurotoxicity in patients over 60 years of age, a group of patients frequently affected by this pathology. To resolve these and other questions it is necessary to deep in the study of primary cerebral lymphoma and to carry out high quality clinical trials.