A cyst in the ankle area could be a tendon sheath cyst or a cystic change in the bone in the ankle area. But whichever it is, it is a benign bone tumor and the possibility of cancer is very, very small. The former is a result of the tendon sheaths and tendon movement in the ankle joints, resulting in an oozing, encapsulated fluid; the latter is a cystic lesion in the bone that grows very slowly and has clear borders. Both of these lesions can be considered for simple surgical treatment when appropriate clinical symptoms develop. Although both have the possibility of recurrence, surgical treatment can basically solve the problem without metastasizing to distant sites. Therefore, the chance of recurrence is smaller than that of malignant tumors of cancer, and the effect of recovery is also smaller, with no impact on daily life and other aspects of the body.