[Medical Q&A] What is the most common malignant bone tumor?

Planner: Chinese Medical Association

Reviewer: Shao Zengwu, Chief Physician and Professor of Union Hospital affiliated to Tongji Medical College, Huazhong University of Science and Technology

The most common malignant bone tumor is osteosarcoma.

Osteosarcoma refers to a malignant tumor that originates from mesenchymal tissue and in which stromal cells can generate bone-like tissue. The bone-like tissue produced by osteosarcoma is osteoid or immature bone, so it is also called "osteosarcoma". Osteosarcoma is the most common malignant bone tumor, accounting for about 20% of primary malignant bone tumors. The peak incidence of osteosarcoma is bimodal, with the first peak occurring between 10 and 20 years old, which is the most active growth of adolescents, and the second peak occurring after the age of 50. In adolescents, osteosarcoma is prone to occur in appendicular bones, especially the distal femur and proximal tibia near the knee joint, accounting for about 50%, followed by the proximal humerus, and is rare in the forearm and hands and feet. In elderly patients, osteosarcoma is prone to occur in axial bones and flat bones, such as the spine and pelvis.

The most common symptom of osteosarcoma is pain, which can last for weeks or months. In the early stage, it is mostly dull pain, which is persistent and worsens after activities, and is often accompanied by night pain. A lump appears in the affected area and gradually increases in size. When the lump increases to a certain extent, the movement of the affected limb and joints is restricted. The lump is accompanied by local tenderness, and symptoms such as increased skin temperature and surface venous distension of the affected limb may occur. Some patients are found to have pathological fractures when they seek medical treatment after imaging examinations due to accidental trauma. Fever, weight loss, anemia and other manifestations may occur in the later stages of the disease. Osteosarcoma often metastasizes to the lungs, which may be asymptomatic in the early stages and hemoptysis, dyspnea and other manifestations may occur in the late stages.