Abstract
Endometrial stromal sarcoma metastases usually occur within the pelvis and rarely involve the great vessels or the heart. We present the case of a 55-year-old woman who was referred for endovascular therapy to treat presumed thrombosis of the inferior vena cava. The suspected thrombus was recalcitrant to endovascular removal with use of an AngioVac venous drainage device. Results of an intraprocedural transvenous biopsy revealed the mass to be the intravascular extension of an endometrial stromal sarcoma. The patient underwent surgical excision of the tumor, and, shortly thereafter, a hysterectomy and salpingo-oophorectomy. This complex case highlights both the rarity of malignancy masquerading as caval thrombus and the importance of multispecialty collaboration.