EBV seropositive. Antibody responses indicate prior exposure to EBV. Most people worldwide are seropositive. Typically, this is defined by the presence of immunoglobulin specific for viral capsid antigen (VCA) or EB nuclear antigens (EBNA).

Infectious mononucleosis. Symptomatic primary infection characterized by pharyngitis, lymphadenopathy, lymphocytosis and serologic evidence of recent infection (e.g., Monospot test, heterophile antibody, VCA IgM).

EBV⁺ HL. Tumor cells in diagnostic tissue show viral RNA or protein when assessed by in situ hybridization or immunohistochemistry.