Dorsal tendon sheath cyst belongs to the benign mass on the back of the foot, the swelling and pain may be due to the tendon sheath cyst is relatively large, repeated friction to form the pain, and may be accompanied by local infections and other problems, you can consider to improve the ultrasound examination, to determine the size of the dorsal tendon sheath cysts, the scope, and and the relationship with the important blood vessels, nerves, tendons. If the localized tendon sheath cyst is large, affecting the normal wearing of shoes and appearance, and the pain is obvious, surgery can be performed to remove it. After surgery, routine pathologic examination should be done to rule out any other masses. After surgery, keep the wound dry and keep changing the medicine, usually every 2-3 days, and the stitches can be removed 2 weeks after surgery. Try to avoid long-distance walking, strenuous exercise, repeated friction localization, to reduce the possibility of recurrence.