The possibility of dorsal bulge of foot is generally lower than that of bone cancer. Malignant tumors of bone usually occur in the epiphysis of long bones of limbs, and dorsal bulge of foot may be caused by dorsal tendon sheath cyst, fasciitis, dorsal dermal cyst and so on. 1. Dorsal tendon sheath cyst: chronic strain, mechanical stimulation, trauma and other factors lead to the accumulation of fluid in the joint cavity of the dorsum of the foot, the formation of cystic swelling, manifested as a bulge. 2. Dorsalis pedis fasciitis: aseptic inflammation caused by excessive force and pulling of the dorsalis pedis fascia, some of which may appear as redness and swelling of local tissues. 3. Dorsal epidermal cysts: benign cysts occurring in the skin, belonging to a kind of dermatosis, occurring on the back of the foot can be manifested as a semicircular bulge, hard texture. There are other common causes of dorsal foot bulge, such as bone cysts, osteochondroma, fracture deformity healing, etc., should be timely to the hospital, improve the relevant examination, clear cause of the targeted treatment in accordance with the doctor’s instructions, so as not to delay the condition.