Primary central nervous system lymphoma (PCNSL) is an extranodal non-Hodgkin's lymphoma confined to the brain, leptomeninges, spinal cord, or eyes without systemic involvement. Nearly half of patients with PCNSL who achieve complete remission, relapse within five years. The majority of patients who relapse have a local recurrence. Systemic relapse, however, is much rarer. Here, we report a rare case of a 70-year-old male diagnosed with PCNSL who relapsed systemically nearly 1.5 years after achieving complete remission. His treatment consisted of chemoimmunotherapy and targeted therapy followed by an autologous transplant. Currently, there is no standard of care for systemic relapse of PCNSL. This multiagent treatment modality may be one such option for salvage therapy.