A case of a recurrent low-grade endometrial stromal sarcoma extending to the inferior vena cava (IVC) after the primary fertility-sparing surgery.

INTRODUCTION AND IMPORTANCE: A case of Low-grade endometrial stromal sarcoma (LG-ESS) invading the great vessels is rare.

CASE PRESENTATION: A 34-year-old female who had no past history presented to a previous hospital with abdominal distension. Magnetic resonance imaging revealed a 15 cm pelvic mass beside the uterus, and only the pelvic mass was removed at the surgery. The tumor was judged to be a LG-ESS. The patient chose to be observed to preserve her fertility, and no adjuvant treatment was undertaken. Two years later, she was referred to our hospital due to recurrence of the pelvic mass. Enhanced computed tomography revealed a large tumor in the vena cava which extended from the left internal iliac vein and which originated from the pelvic tumor. An operation was performed by a multidisciplinary team. Complete resection of the tumor was achieved with a radical hysterectomy, bilateral salpingo-oophorectomy, removal of recurrent pelvic masses and the intravascular tumor. We diagnosed a recurrence of LG-ESS. She received a postoperative adjuvant therapy of LG-ESS.

CLINICAL DISCUSSION: Patients with fertility-sparing treatment had higher recurrence rates. In cases of tumor intravenous extension, we should make every effort to extract the tumor to avoid sudden death.

CONCLUSION: This case highlights the importance of a multidisciplinary approach in treating this rare tumor with intravascular extension. In particular, patients with LG-ESS who receive fertility-sparing surgery should undertake postoperative chemotherapy or radiotherapy in order to reduce the risk of recurrence, as was in this case.