A leg cyst, also called a popliteal cyst, is a cystic change that grows in the popliteal fossa and can be treated conservatively by aspiration of the cystic fluid if you do not want to have surgery. However, the results of this conservative treatment are not ideal and are determined on a case-by-case basis. Aspiration of the cyst is a treatment that involves disinfecting the local skin surface under the guidance of a physician, then puncturing the popliteal cyst with a puncture needle and using a sterile syringe to extract the contents of the popliteal cyst. If necessary, tretinoin acetate can be injected to effectively reduce the size of the popliteal cyst, thereby reducing the pressure on the surrounding tissues and gradually eliminating the discomfort caused by the popliteal cyst in order to achieve a certain degree of therapeutic effect. However, it should be noted that this conservative approach is prone to the recurrence of popliteal cysts and requires multiple treatments to maintain them. In addition, in daily life, before popliteal cysts are completely cured, patients should also reduce the movement of the affected lower limb to avoid aggravation of symptoms due to prolonged compression.