Abstract
Systemic chronic active Epstein-Barr virus (EBV) disease is a rare, delayed, and life-threatening complication of EBV infection. It is characterized by persistent viremia and a mononucleosis-like syndrome with multisystemic involvement because of lymphocytic tissue infiltration. We present the case of an 82-year-old woman without known immunodeficiency who presented with abnormal liver enzymes and interstitial pneumonia. Investigations revealed hyperferritinemia, elevated soluble interleukin-2 receptor levels, hypofibrinogenemia, and hepatosplenomegaly, consistent with hemophagocytic lymphohistiocytosis, as well as a high EBV viral load. Liver biopsy demonstrated portal chronic lymphocytic inflammation and positive EBV in situ hybridization, suggesting systemic chronic active Epstein-Barr virus disease as the underlying etiology.