Tumor viruses in CD30-positive anaplastic large cell lymphomas

CD30+ anaplastic large cell lymphoma (ALCL) represents a novel lymphoma entity at the borderline between Hodgkin's disease and non-Hodgkin's lymphomas. Phenotypic, genotypic, and karyotypic analyses have shown that ALCL are heterogeneous in cellular origin, and may be conceived as malignancies derived from activated, mainly T- or B-lymphoid cells, in some instances with an immature genotype. Epstein-Barr virus genomes and gene products, most notably the transformation-associated latent membrane protein (LMP), have been detected in a proportion of cases, and some cutaneous ALCL proved to harbor complete or incomplete HTLV-1 proviruses. These findings suggest that both EBV and HTLV-I, which are powerful inducers of CD30 expression in lymphoid cells in vitro, may contribute to the pathoetiology of ALCL.