Introduction: Uterine sarcomas are rare tumors, with 3-7% incidence. Abnormal uterine bleeding, abdominal or pelvic masses, and pain are the most common symptoms in the patient. Non-specific clinical symptoms or preoperative diagnostic techniques to differentiate uterine myoma and uterine sarcoma lead to the general diagnosis after surgery. The incidence of uterine sarcoma established from the literature was 0.09% -0.49% in women undergoing benign hysterectomy or myomectomy. The difficulty of diagnosing preoperative leiomyosarcoma is a challenge in itself. This case report aims to provide knowledge information with characteristics of a sonographic image with a non-hypervascularity encapsulated image and intraoperative findings with a regular smooth uterine surface, which is thought to be a uterine myoma is different from the anatomical pathology results, which indicate a leiomyosarcoma malignancy.Case description: Miss A, 47 years old with complaints of an enlarged stomach for two years, felt abdominal pain and complained about prolonged menstruation for four years. The patient was unmarried and had no previous history of surgery. Intraoperatively, there was posterior corpus adhesion with ascending colon and adhesion was performed. Large, fragile blood vessels appeared. Then it was decided to do a total abdominal hysterectomy—intraoperative hemorrhage 1200 cc. The results of the anatomic pathology showed a leiomyosarcoma. Furthermore, the patient was consulted to the oncology subdivision for a bilateral Salpingo-Oophorectomy procedure followed by chemotherapy. MRI, 3D Doppler sonography were required to increase the preoperative diagnosis of uterine sarcoma.Conclusion: Our case reported that a patient was diagnosed with uterine myoma and stage II hypertension. The patient showed common signs and symptoms. There was posterior corpus adhesion with ascending colon, and adhesion was performed. Theoretically, pelvic sonography is a first-line imaging study. MRI can be used to help differentiate uterine sarcomas from uterine myomas.