Morphologic patterns and molecular pathways of AIDS-related head and neck and other systemic lymphomas

Head and neck manifestations of human immunodeficiency virus (HIV) infection include lymph nodal and extranodal localization of non-Hodgkin's lymphoma (NHL). A histopathologic characteristic common to head and neck NHLs and to all the other systemic lymphomas in HIV patients is the frequent occurrence of cases displaying pleomorphic features and some overlap between established histologic subtypes. This article highlights the difficulties in defining HIV-related NHLs correctly, and proposes a specific pathologic categorization of these disorders accounting for their pathogenetic aspects as gathered from molecular data.