Sarcoma, KaposiSarcomaHerpesvirus 8, HumanSarcoma, EwingSarcoma, SynovialAvian Sarcoma VirusesSarcoma, ExperimentalSarcoma 180Sarcoma Viruses, MurineLymphoma, Primary EffusionSicilyGiant Lymph Node HyperplasiaHerpesviridae InfectionsSoft Tissue NeoplasmsSarcoma, AvianHistiocytic SarcomaSarcoma, MyeloidSarcoma, Endometrial StromalSarcoma, Clear CellAcquired Immunodeficiency SyndromeDelayed DiagnosisSarcoma, YoshidaKirsten murine sarcoma virusPrenatal DiagnosisEarly DiagnosisMoloney murine sarcoma virusSarcoma Viruses, FelineSkin NeoplasmsSensitivity and SpecificityRetrospective StudiesBone NeoplasmsViral ProteinsHemangioendotheliomaLymphoma, AIDS-RelatedRous sarcoma virusBiopsyDiagnosisLeiomyosarcomaPolymerase Chain ReactionOsteosarcomaSarcoma, Alveolar Soft PartTreatment OutcomeDNA, ViralRNA-Binding Protein EWSHIV InfectionsAIDS-Related Opportunistic InfectionsIncidenceTime FactorsImmunohistochemistryTomography, X-Ray ComputedDiagnostic ErrorsChilblainsAlpharetrovirusProto-Oncogene Protein c-fli-1Virus LatencyAntigens, ViralCell Transformation, ViralHarvey murine sarcoma virusRhabdomyosarcomaRisk FactorsPrognosisHistiocytoma, Malignant FibrousLiposarcomaGammaretrovirusFatal OutcomeAntiretroviral Therapy, Highly ActiveNeoplasmsOncogene Proteins, FusionCell Transformation, NeoplasticCohort StudiesBase SequenceCell LineDoxorubicinFollow-Up StudiesPredictive Value of TestsNephrogenic Fibrosing DermopathyLymphomaProspective StudiesCD4 Lymphocyte CountVascular NeoplasmsHistiocytoma, Benign FibrousNuclear ProteinsViral LoadMagnetic Resonance ImagingNursing DiagnosisHIV SeronegativityHemangiomaDiagnosis, Computer-AssistedMolecular Sequence DataSarcoma 37Antibodies, ViralRetroperitoneal NeoplasmsItalyReproducibility of ResultsUgandaRNA, ViralHIV SeropositivityHerpesvirus 7, HumanSarcoma, Small CellBiopsy, Needle