Hemophagocytic lymphohistiocytosis (HLH) is a syndrome characterized by aberrant immunological activity with a dismal prognosis. Epstein-Barr virus-associated HLH (EBV-HLH) is the most common type among adults. Patients with EBV infection to B cells could benefit from rituximab, whereas lethal outcomes may occur in patients with EBV infection to T cells, nature killer (NK) cells, or multilineages. The necessity of allogeneic hematopoietic stem cell transplantation (HSCT) in adult …