Leg pain may be an early manifestation of malignant tumors of the leg, such as osteosarcoma of the leg, Ewing’s sarcoma and so on. In addition, leg pain is often a symptom of arthritis, lower limb thrombosis and other benign diseases, or a common symptom of cancer patients in the late stage. Osteosarcoma or Ewing’s tumor, which are malignant tumors originating from the bones of the lower limbs, often present with bone pain in the legs in the early stage. In addition to this, patients are often accompanied by soft tissue masses in the area of localized bone lesions, etc. Patients usually do not have only the symptom of leg pain. But more often than not, leg pain is a clinical symptom due to arthritis, lower extremity thrombosis, trauma, or benign non-cancer diseases such as lumbar disc herniation. When distant metastases to the femur and lumbar vertebrae occur in the advanced stages of cancer disease, many of these will also manifest as leg pain.