The symptoms of Ewing sarcoma will depend on the size of the cancer and where it is in the body. The main symptoms are pain in the affected area that gets progressively worse and swelling and tenderness. Other possible, but less common, symptoms may include a high temperature (fever), severe tiredness and weight loss. In some cases of Ewing sarcoma, there may not be any symptoms at all. However, as the tumour grows it could weaken the affected bone, increasing the risk of fracture.