Presentation
Knee pain.
Patient Data
A illdefined lucent lesion involves the metaphysis and distal diaphysis of the femur. It does not appear to quite reach the growth plate. Laterally the mass elevates the cortex with periosteal reaction (Codman triangle).
Delayed images of a bone scan demonstrate the femoral lesion to have increased activity. No other lesions evident.
Selected coronal and axial images through the femoral tumor demonstrate enhancement and extension beyond the cortex with enhancement and edema involving the adjacent soft tissues.
Case Discussion
Multi-modality imaging is characteristic of an osteosarcoma of the distal femur which was subsequently histologically proven.