简介：Tostudytheclinicalpathologicalcharacteristicsanddifferentiationdiagnosisofthechondroidparachordomafromprimarytumorsormetastatictoulna,femurandradius.MethodsThreecasesofprimarychondroidparachordomaoftheulma,femurandradiuswerestudiedbyhistopathologicalobservationandimmunohistochemicalstainingandbypathologicalconsultation.ResultsThehistologicalfeaturesoftumorwerecomposedoftwothechordomaceilssubtotalandthechondrosareomaceilsofsmall-portio.Thetumorwasarrangedvaryinsizesoflobularandbrinkoflobularwereseplumsmallgirderofchondroid,orthetissuefiber.Thetumorcellsweredistributedsheet,trabeculawithorisland-likeintheintralobular,andthetumorceilswerevaryinsizeandthekaryonheterotypicwerenopatentandthecytoplasmofrichshowslargevacuole.Thechondroidosarcomasintra-lobularwereviewedceilsbothnucleusanduninuclearofchondrolacunaeandthestromawerehyalingcartilagewithorblennoidinthemesenchyma,andthatpictureoftypicalchondrosarcoma.EMA,CK,Vimentin,S-100protein,NSEwithimmunohistochemicalmethod(ABC)stainingwerepositiveandDesmin,CD34negativeinthealloftumorcells.Thechondroidparachodomawasdiagnosedinthepathologicalread-section-conferenceandconsulation.ConclusionPrimaryulna,femurandradiuschondroidparachordomaisarareinrateofneoplasmandisdiagnoseddiflqculdy.Immunohistochemicalmethodwouldbehelpfultodiagnosis.