Bone tumors are neoplasms arising from bone tissue or its附属 structures (vessels, nerves, bone marrow, fat, etc.), classified into three main categories: benign bone tumors, primary malignant bone tumors (e.g., osteosarcoma, chondrosarcoma, Ewing sarcoma), and metastatic bone tumors (the most common malignant bone lesions, originating from primary cancers of the lung, breast, prostate, thyroid, and kidney).

• Etiology: The pathogenesis of most bone tumors remains unclear, with implicated risk factors including genetic mutations, hereditary syndromes, radiation exposure, chronic inflammation, and prior bone trauma.
• Epidemiology: Benign bone tumors are significantly more common than malignant tumors, with an excellent prognosis. Primary malignant bone tumors are rare, with an annual global incidence of approximately 3-5 per 1 million people, most commonly affecting children and adolescents (osteosarcoma peaks at age 10-20). Metastatic bone tumors are far more prevalent, affecting 30-40% of patients with advanced solid tumors, most commonly in middle-aged and elderly adults.
• Clinical Manifestations: Benign bone tumors are often asymptomatic, presenting only as a slow-growing painless mass, with rare pathological fractures. Malignant bone tumors are characterized by progressive local pain (worse at night), a rapidly growing soft tissue mass, swelling, pathological fractures, and systemic symptoms (weight loss, anemia, fever) in advanced disease. Metastatic bone tumors most commonly present with intractable bone pain, pathological fractures, hypercalcemia, and spinal cord compression.
• Diagnosis: Diagnosis requires a combined clinical-radiological-pathological approach. Imaging studies include X-rays, CT, MRI, whole-body bone scan (ECT), and PET-CT to assess tumor extent, local invasion, and systemic metastasis. Histopathological biopsy is the gold standard for definitive diagnosis and tumor classification.

Treatment is personalized based on tumor type, grade, stage, location, and patient age, with a multidisciplinary team (MDT) approach as the standard of care:

• Benign Bone Tumors: Asymptomatic lesions with no malignant potential are managed with regular follow-up. Symptomatic lesions, aggressive benign tumors, or those with malignant potential are treated with surgical curettage or en bloc resection with bone grafting, with a near 100% cure rate.
• Primary Malignant Bone Tumors: A multidisciplinary comprehensive treatment approach is standard. For osteosarcoma and Ewing sarcoma, the standard protocol is neoadjuvant chemotherapy followed by definitive surgery and adjuvant chemotherapy. Limb-salvage surgery is the first-line surgical option for over 90% of patients, with amputation reserved for advanced, unresectable tumors with neurovascular invasion. Radiotherapy, targeted therapy, and immunotherapy are used for select tumor subtypes and advanced disease.
• Metastatic Bone Tumors: Treatment is palliative and multidisciplinary, with the goals of relieving pain, preventing skeletal-related events (pathological fractures, spinal cord compression), improving quality of life, and prolonging survival. Interventions include treatment of the primary tumor, radiotherapy, chemotherapy, targeted therapy, immunotherapy, bone-modifying agents (bisphosphonates, denosumab), and palliative surgery (pathological fracture fixation, spinal cord decompression, tumor resection).