HHV-8 is a gamma herpes virus described for the first time in humans in 1994 within Kaposi's disease cells. Since, it has been found to be involved in lymphoid proliferative disorders. First, it has been described in multicentric Castleman's disease (100% of HIV infected patients and 50% of HIV negative patients), in multicentric Castleman's disease associated lymphomas and in cavitary and extracavitary primary effusion lymphomas (100% of cases). More recently, some other HHV-8 associated lymphoproliferations have been described. We describe in this review the characteristics of this virus, along with the clinical, pathological and molecular characteristics of the different entities associated with HHV-8. (C) 2009 Elsevier Masson SAS. All rights reserved.