Abstract: objective:Exploring the clinical,radiologic features of uterine intravenous leiomyomatosis(IVL) to promote awareness of the disease.Methods:3 cases of IVL with inferior vena cava and right atrium involvement were retrospectively analyzed.Results:Among the 3 patients,2 had previous hysteromyomectomy history,one is first onset.Two patients went to hospital because of lower extremity edema and nocturnal dyspnea,and one due to hydronephrosis.CT scan found huge abdominal and pelvic masses with lobulated surfaces and multiple nodular enhancements,meanwhile increased and widen pelvic veins were visualized with tumor thrombus formation and extending from the internal iliac vein into common iliac vein and then the inferior vena cava.In one case the tumor thrombus even spreads into the right atrium and causes liver congestion.Conclusion:IVL is a rare variant of uterine fibroids with different characteristics of incidence,imaging findings and course.The tumor may spread from pelvic veins upward to the inferior vena cava or even right atrium causing threat to patient's life.It is important to raise the awareness of IVL.