Recently, orthopedic department admitted a patient with huge thigh mass, patient, female, 71 years old, Tonglu, Zhejiang Province, found that the left thigh mass has been slowly increasing for more than 10 years, and in the past one and a half years, it was found to be rapidly increasing, the patient heard that our orthopedic department’s treatment of soft tissue sarcoma is quite distinctive, and then she was transferred to our hospital to request for surgical treatment. Dr. Zou Cheng, deputy chief physician of orthopedics department, did a comprehensive examination after receiving the patient. MRI showed that the signal of the thigh tumor was fat, but the internal signal was not uniform, and combined with the history of rapid tumor enlargement, the tumor was probably liposarcoma, which was unusually huge, occupying the whole inner thigh, and was in close proximity to the femoral artery, vein and sciatic nerve, which made it difficult for limb-sparing surgery. After thorough preoperative preparation and 4 hours of struggle, Dr. Zou Cheng, deputy chief physician, and Dr. Yao Wangxiang, attending physician, finally resected the tumor together with the periphery and the superficial layer of the suture muscle, which was tightly adhered to the femoral artery and sciatic nerve, so the two doctors calmly separated the tumor from the nerves and blood vessels. The resected mass was measured as 32*25*21CM3 and weighed 25 pounds. The patient recovered well after the operation and could walk on the ground one week later. The postoperative pathology report confirmed the previous judgment, and the pathology report was “highly differentiated liposarcoma”. The stitches were removed 2 weeks after the surgery and the old lady went home. Highly differentiated liposarcoma is a low-grade malignant soft tissue sarcoma, which is the most common type of liposarcoma in the clinic. Generally, the recurrence rate is less than 5% after complete extraperitoneal resection.