Objective: Toreportmediastinalracemosehemangiomasecondarytocomplexcoronaryarteryfistulasinanadultandconducta briefreviewoftheliteraturesoastoimprovediagnosticawareness. Method: Thepatientsdatafromourhospital,includingclinicaldataandimagingdata,wasretrospectivelyanalyzed Results: A 56-year-old man with a history of renal calculus 3 years before was admitted to our hospital, complaining of chest tightness under the xiphoid, head dizziness and headache three days previously. These symptoms were not associated with exertionalexerciseandpositionchange.Afteroralquick-actinghearttreatmentpill,thepatientssymptomsdidnotimprove.The patients condition was well without clinical evidence of congestive heart failure. Blood chemistries, including coagulation studiesandcompletebloodcellcount,aswellascardiacenzymesandlipidprofiles,wereallwithinthenormallimits.Coronary angiographydemonstratednosignificantnarrowingofthreemajorcoronaryarteries(Fig1-2).However,adilated,tortuousvessel originatingfromthebranchofleftcircumflexcoronaryarterywasnoticedassociatedwithlowlyemptying,butunabletodefine itstermination.HesubsequentlyunderwentanECG-gatedcontrast-enhancedcoronaryCTangiographyusingadual-source128 slicemultidetectorCT(Siemens, ErlangenGerman).Thisdemonstratedalargetortuous,dilatedvesselswiththecommunication betweenthebranchofleftcircumflexarteryrunningalongthedomeoftheleftatriumandthebranchofdescendingthoracic arotainthemedium(Fig3).Thesetortuous,dilatedvesselswasascertainedtohavemicro-communicationwithrightpulmonary trunk owing to its earlier shadow(Fig4), without similar change in the left pulmnoary artery. Finally, complex coronary artery fistulas with multiple sites of origin and drainage were diagnosed. The patient refused any intervention although treatment modalities including surgical ligation and transcatheter closure were proposed. On the follow up of six months, his condition remainedstable. Conclusion:Acoronaryarterialfistulaisaconnectionbetweenoneormoreofthecoronaryarteriesandacardiacchamberor greatvessel,havingbypassedthemyocardialcapillarybed.Anyofthethreemajorcoronaryarteriescanbethefeedingarteryfor thecoronaryfistula:rightcoronaryartery(37%),leftcoronaryartery(33%),leftanteriordescendingartery(26%),andleftcircumflex artery(4%).Feedingarteryfromthebranchofaortaisrarelyreportedintheliterature.Thecommunicationsiteofthecoronary artery could include: right ventricle accounting for 41%, right atrium 26%, left atrium 5%, left ventricle 3%, coronary sinus 7%, superiorvenacava1%,pulmonaryartery17%orthepulmonaryvein.Itisimportanttoalertthattheremaybemultiplefeeding arteriestoasingleCAFdrainagepointortheremaybemultipledrainagesites,asdescribedinourpatient. Complexcoronaryarteryfistulawithmultiplesitesoforiginanddrainagemaybechallengingtodiagnose,andMSCTwithmultiplanar and3Dreconstructionsarevitalinprecisecharacterizationofthefistulaanatomy.Moreover,coronaryCTAhadbetterbe performedinallpatientswhereadiagnosisofCAFhasbeenmadeviaconventionalangiography.