Low-Grade Endometrial Stromal Sarcoma Extending to The Right Atrium

Endometrial Stromal Sarcoma (ESS) are very uncommon malignant tumors that make around 0.2% of the entire uterine related malignancies. They represent the endometrial stromal cells in the proliferative stage. The annual incidence of ESS is 1-2 per million women. We present an unusual case of ESS, which originates from the uterine artery through the Inferior Vena Cava (IVC) and extends to the right atrium. A 48 years old woman presented with menorrhagia and right flank pain for seven months. Physical examination was normal except for a palpable suprapubic mass. Computed tomography (CT) showed the right gonadal vein and IVC tumoral thrombus extending into the right atrium. An echocardiogram and Transesophygeal echocardiogram revealed a large non-mobile echogenic density in the right atrium. Total abdominal hysterectomy with bilateral salpingo-oophorectomy was done. Extensive myometrial and vascular invasion was noted along with the extensive lymphovascular invasion of the uterus. Eventually, distal IVC resections were done, and there was no chance to remove the tumor because it was too attached and invaded the IVC filter. Owing to the unresectability of the tumor, the patient was assigned for palliative chemotherapy. Keywords: Endometrial Stromal Sarcoma, Right Atrium, Inferior Vena Cava, Spindle Cell Sarcoma.