The nature of the swelling next to the knee should be determined by a specialist before deciding on the next step of treatment. A detailed specialist examination is performed by the physician to determine the size, texture, mobility, and softness of the swelling next to the knee, whether there is significant pressure pain and whether there are distant metastases. Then, according to the specific examination results, with further auxiliary examinations, such as ultrasound, CT or MRI, and if necessary, puncture biopsy, to determine the nature of the swelling, the next step of treatment needs to be done according to the nature of the swelling. If the mass is benign and has no effect on daily life, it can be closely observed, and if it has an effect on daily life, it can be surgically removed. If it is a malignant tumor, it must be removed by surgery as soon as possible, and appropriate radiotherapy or chemotherapy treatment should be done according to the nature and sensitivity of the tumor.