Abstract
OverviewBone tumors are uncommon lesions that affect all ages of patients and may involve any bone in the body. Bone lesions may be benign neoplasms or reactive lesions, primary bone sarcomas, metastatic carcinomas to bone, myeloma, or lymphoma. The benign bone lesions, which predominate in children and young adults, may behave in an inactive, active, or aggressive fashion, and the latter may simulate malignancy. Primary bone sarcomas have a bimodal distribution, whereas metastatic disease, myeloma, and lymphoma of bone predominate in adults. Despite the broad spectrum of bone tumors, each individual entity has a distinct clinical and radiographic presentation, with a predilection for specific locations, which lends itself to narrowing the differential diagnosis and selecting appropriate management.Bone sarcomas account for less than 0.2% of all cancers. During 2014, approximately 3020 new cases of primary bone sarcomas were diagnosed, and approximately 1460 deaths occurred. The three most common bone sarcomas are osteosarcoma, chondrosarcoma, and Ewing sarcoma. However, the most common primary malignancy of bone is myeloma, and the most common cancer that involves bone is metastatic carcinoma.The pathologic classification of bone tumors continues to evolve. To a large extent, classification continues to be according to the cell of origin or tissue type. Primary bone tumors may derive from cartilage cells, bone cells, and vascular cells, among others, but for some tumors, the cell of origin is unknown. The most widely accepted pathologic classification system to date is that of the World Health Organization.