History:A59-year-oldmaninitiallypresentedtoanoutsidehospitalwithrightflankpainandgrosshematuriaduetoapartiallyobstructingrightureteralcalculus.

病史：59岁男性，最初因右输尿管结石导致右腹痛、肉眼血尿在外院就诊。

Findings

CoronalCTimage(a)demonstratesawell-circumscribedhomogeneousfat-attenuatingintravascularmass(arrows)extendingfromtherenalveinstotheinferiorvenacava(IVC).AxialT2MRimage(b)showsahyperintenseroundmassintheIVCthatsubtractsoutonpostcontrastT1fat-saturatedaxial(c)andcoronal(d)MRimages,aswellasdemonstrateschemicalshiftartifactonout-of-phasecoronalMRI(e).Thelesionisspacefilling,nonenhancingandnearlyallfat,most