Due to the low incidence of bone tumor, patients know little about it, and sometimes they mistakenly think it is a muscle strain or strain injury and do not go to the clinic. Early detection of bone tumor has a great impact on the diagnosis and treatment of doctors and the prognosis of patients, so it is very important to be familiar with the common symptoms of bone tumor for early detection and timely consultation. 1.How to detect bone tumor in early stage (what are the symptoms)? Bone tumors often have no obvious symptoms in early stage, and even if there are slight symptoms, they are easy to be ignored. With the development of the disease, a series of symptoms and signs may appear, especially the local symptoms and signs are more prominent. Pain, mass and functional impairment are considered as the three main symptoms of bone tumor, especially malignant bone tumor. (1) Pain: This is the main symptom of bone tumor in the early stage, which is generally mild at the beginning and often intermittent, but with the progress of the disease, the pain can gradually increase and develop from intermittent to continuous, especially at night. Some benign tumors, such as osteoid osteoma, can cause pain in response to the growth of bone. A sudden and severe attack of pain is likely to be a pathological fracture. (2) Mass: It usually appears after the pain has occurred for a certain period of time and is localized in the bone or bone joint. Slow-growing tumors or tumor-like lesions rarely have significant swelling and are not detected until dysfunction occurs or a pathological fracture occurs. (3) Dysfunction and compression symptoms: In the late stage of bone tumor, dysfunction of the affected part will appear due to pain and swelling, and the symptoms of dysfunction will be more obvious if the disease develops rapidly, which may be accompanied by muscle atrophy in the corresponding area. If the tumor is close to the joint, the activity function will be restricted and the pain will be aggravated when moving. Tumors in the spine, no matter benign or malignant, can compress the spinal cord and cause paralysis. In addition, skin and local vascular signs may appear: if the tumor is rich in blood vessels, the skin color may change significantly, the skin may become hot, and the superficial veins may become angry. When the above symptoms are found in the early stage, we should be alert to the occurrence of bone tumor and go to the bone tumor specialist for systematic examination in time to avoid delaying the disease. 2.What is the difference between symptoms of benign and malignant bone tumor? (1) Benign bone tumor usually develops slowly and has no obvious early symptoms, pain and swelling are not very obvious, only when it grows to a certain extent near the joint, it may cause mild dysfunction or deformity. Benign bone tumor usually has a solid and fixed mass, growing on the side of bone end, with clear boundary, smooth surface and no pressure pain. (2) Malignant bone tumor develops quickly, with pain first, followed by swelling, pain persists, usually without remission period, and the symptoms become more and more severe. The boundary of the mass is not clear, the skin temperature is high, the pressure pain is obvious, and there are joint movement disorders. 3.Diagnosis of bone tumor. Only a few common bone tumors are relatively easy to diagnose, and most of them are difficult to diagnose. Because different bone tumors can have similar clinical manifestations; different nature of bone tumors can have the same features in imaging; benign bone tumors can become malignant. It is up to the specialist to determine: (1) whether it is a bone tumor; (2) whether it is a benign or malignant bone tumor; (3) whether it is a primary or metastatic bone tumor. The diagnosis of bone tumor must be made by a comprehensive analysis of clinical, imaging and pathological aspects.