Background. Autoimmune lymphoproliferative syndrome (ALPS) is a genetic disorder of lymphocyte homeostasis due to defects in FAS-mediated apoptosis. ALPS is characterized by childhood onset of chronic lymphadenopathy and splenomegaly, autoimmunity, an expanded population of double-negative T cells (DNTCs), and an increased risk of lymphoma. This propensity for lymphoma in ALPS is not well understood. It is possible that lymphomagenesis in some of these patients may result from Epstein-Barr virus (EBV) infection exploiting the defective T-cell surveillance resulting from impaired FAS-mediated apoptosis. Case Presentation. We report the first case, to our knowledge, of lymphoma in a patient with ALPS that was clinically heralded by progressively increasing EBV viremia. We discuss its practical implications and the possible immune pathways involved in the increased risk for EBV-associated lymphoproliferative disorders in ALPS patients. Conclusion. In patients with ALPS, distinguishing chronic lymphadenopathy from emerging lymphoma is difficult, with few practical recommendations available. This case illustrates that, at least for some patients, monitoring for progressively increasing EBV viremia may be useful.