Endometrial stromal sarcoma (ESS) is a rare malignant tumor. There is insufficient data supporting the efficiency of current treatments in multiple metastatic settings, and novel therapeutic options for ESS are considered an area of high unmet clinical need.We report the case of a 28-year-old woman who was diagnosed with ESS after undergoing total hysterectomy and left adnexectomy at another hospital. Two years later, the disease recurred, with multiple abdominal cavities and lung metastases. The patient was treated with a variety of chemotherapeutic drugs, including tyrosine kinase inhibitors, at the same hospital; however, none of them inhibited disease progression.Computed tomography (CT) revealed multiple masses in the abdominal and pelvic cavities and multiple pulmonary nodules. Ultrasound-guided biopsy was performed and the tumor tissue was histologically confirmed after treatment.Insulin 300-400 IU was administrated by intravenous infusion in 10% glucose (500 mL) with disodium adenosine triphosphate 60 mg, coenzyme A 100 units, 10% potassium chloride 5 mL and 25% magnesium sulfate 5 mL. Dexamethasone (20-25 mg/d) was diluted with 10 mL of 2% lidocaine and then intraperitoneally injected after ascites draw. After 9 months, the patient was referred to another center for radiotherapy.CT images tomography showed recurrent pelvic masses, and multiple abdominal cavity and lung metastases gradually shrunk with treatment. Histological biopsy revealed growth arrest of tumor cells. The patient experienced for 3-years survival.High-dose insulin and dexamethasone combined with radiotherapy provides a novel and promising option for patients with multiple ESS metastases.Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.