Endometrial stromal sarcoma metastatic to the inferior vena cava: a case report and literature review.

Background: Endometrial stromal sarcoma (ESS) is a uterine stromal tumor with a very low incidence, accounting for 10-15% of all uterine stromal malignancies and 0.2% of all uterine malignancies. The most common extrauterine location of ESS is the ovary, and it is relatively rare outside the uterus. Although most recurrences occur within the pelvis, distant metastases can occur. Case Description: We report a rare case of low-grade ESS (LG-ESS) metastatic to the inferior vena cava (IVC) which is difficult to distinguish from leiomyoma clinically. A 56-year-old woman attended outpatient complaining right thigh pain. She underwent a surgery of hysterectomy and bilateral adnexectomy 12 years ago. Abdominal contrast-enhanced computed tomography (CT) demonstrated that the vaginal stump was thick, with peripheral multiple nodular shadow. Soft tissue shadow in the right pelvic cavity. Thickening and enhancement of soft tissue shadow were observed in the peripheral blood vessels of the vaginal stump, the right internal iliac vein and the external iliac vein to the IVC of the liver segment. Malignancy (recurrence or metastasis) were considered. After multidisciplinary consultant, a preoperative diagnosis of leiomyomatosis of the IVC was made and surgical treatment was performed. Surgeons performed laparotomy, resection of tumor in IVC, right common iliac vein, right external iliac vein, right internal iliac vein and left common iliac vein. Post-operative pathology of dissected tumor demonstrated LG-ESS. The source may be the ovarian venous stump left after surgery 12 years ago. After a gynecological consultant, chemotherapy is recommended and is currently under follow-up. Conclusions: We report a rare case of LG-ESS metastatic to the IVC, which was probably a lesion derived from the ovarian venous stump remaining after surgery 12 years ago.