Osteosarcoma with isolated metastases to the pleura.

Osteosarcoma is the most common primary skeletal malignancy of childhood, typically occurring between the ages of 10 and 20. The classic radiographic appearance is that of a mixed lytic and sclerotic lesion originating in the metaphysis of the long bones with cortical destruction, periostitis, and an associated soft tissue mass. Metastatic disease to the lungs is an important prognostic indicator and is found in the majority of patients dying of the disease. We present a child with osteosarcoma of the distal femur who developed extensive metastatic disease involving the chest pleura bilaterally with no other sites of involvement.