Osteosarcoma

Demographic and Clinical Details:

A 16-year-old adolescent girl presented with right knee pain severe enough to wake her from sleep at night.

Imaging Findings:

A two-plane radiograph of the knee revealed an aggressive-appearing lesion in the distal metaphysis and epiphysis of the femur. The lesion displayed mixed density and irregular borders with both sclerotic and lytic areas. A cloud-like ossified matrix was noted within the lesion.

MRI findings demonstrated a heterogeneously enhanced mass lesion following contrast administration. The lesion extended into the surrounding soft tissue, breaching the cortex posteriorly. Additionally, a large area of edema was identified in both the bone and adjacent soft tissues.

Based on the patient’s age and the imaging characteristics of the lesion, the findings are consistent with a diagnosis of osteosarcoma.

Osteosarcomas are malignant bone-forming tumors. They are considered the most common primary malignant bone tumor in children.