 Currently, it is postulated that the originating cell for this disease is a mature (post-thymic) CD4+ T-cell that arises "de novo", although some researchers argue that there is a premalignant subtype of this disease.The Epstein–Barr virus (EBV) is observed in the majority of cases, being identified in the reactive (i.e.non-malignant) B-cells that comprise part of the polymorphous infiltrate of this disease.