Osteosarcoma (osteogenic sarcoma) is the most common primary bone malignancy in the pediatric population. It is more common in males, and patients most commonly present between the ages of 10 and 25. Osteosarcomas can arise from either the medullary cavity or the bony cortex (the periosteal and parosteal forms). The most common sites are the metaphyses of long bones, particularly around the knee (roughly 2/3 of all cases of osteosarcoma arise in the distal femur or proximal tibia).

Radiographic findings include:

• large, aggressive, eccentric lesion (can be either sclerotic, lucent, or both)
• lesions usually do not cross the physis
• "moth-eaten" appearance with "sunburst" periosteal reaction or classic Codman triangle
• pathologic fractures at time of presentation
• large soft tissue component

Plain films accurately depict the nature of the tumor, but MRI and CT are often used to determine the precise anatomic location and soft tissue extension.

Treatment includes surgical removal in conjunction with chemotherapy. Five-year survival is between 75-80%.

Osteosarcomas typically metastasize hematogenously to the lungs and other bones.