Granny Li had pain in her right knee and came to the hospital and found a 2 cm diameter mass on the posterior side of the right femoral epicondyle. The mass was deep and had a large vascular nerve on the surface, which was not large and not easy to take a biopsy and easy to accidentally injure. After discussing with the patient’s family, the patient was directly treated surgically, and the tumor was extensively excised together with the normal tissues on the surface of the mass that did not affect its function. Whether the postoperative examination is benign or malignant, the operation is very thorough and the examination and treatment are completed in one operation. Soft tissue masses are usually tumors, and a small amount is inflammation. Tumor is divided into benign and malignant, and can be divided into different stages according to the growth of tumor. The different nature and stages of the masses lead to different treatment requirements and, crucially, to different surgical scopes. According to the scope of resection, surgery can be divided into intracapsular resection, marginal resection, extensive resection and radical resection. The traditional surgical method only requires resection of the mass, i.e. marginal resection, but modern oncological research has found that the resection scope of malignant tumors and stage III benign tumors should be wide, requiring wide resection or radical resection. Therefore, more tests are usually required before surgery to understand the nature and stage of the mass before deciding on the surgical method. Postoperatively, the decision of further treatment is made based on the results of mass examination. Surgery guided by modern oncology theory can significantly reduce postoperative recurrence and improve prognosis. When a mass grows in the body, do not think that cutting it out is the end of the story anymore, you need to fully understand it before surgery and carefully decide the surgical plan. After surgery, follow the medical advice for further treatment.