Images of Musculoskeletal Oncology
Osteosarcoma
A 12 year old boy c/o right knee pain and swelling for ten days. Painful at rest, worse at night and with activity. Able to ambulate with pain. Initially the pain was accompanied by fever, chills, malaise, nausea and vomiting; most of which have resolved.
This AP radiograph of the distal femur and knee joint reveals a very subtle soft tissue swelling about the distal medial thigh, containing a 1.5 cm area of faint ossification. The distal femoral metaphysis reveals a poorly defined area of increased density without areas of bone destruction. The distal femoral epiphysis appears normal, as does the knee joint.
This lateral radiograph also demonstrates subtle changes of the soft tissue swelling and small amount of new bone are noted in the periphery of the soft tissue swelling.
This MRI of the distal metaphysis reveals soft tissue swelling about the cortex, with cortical thinning and in one area of the medullary canal fairly dense new bone and irregular areas of osteolysis.
This MRI of a cross section of the distal metaphysis clearly reveals new bone and osteolysis, revealing the involvement of the medullary canal and peripheral tissues quite typical of a conventional osteosarcoma.
This MRI of the length of the femur demonstrates the lesion in the distal femoral metaphysis and without skip lesions more proximally in the femur. This is a study important for thoroughly staging the tumor.
The AP MRI of the distal femur reveals the large metaphyseal lesion with peripheral soft tissue swelling, cortical thinning, and bone destruction, a fairly well defined edge in the medullary canal, and some evidence of epiphyseal plate irregularity. The central dark areas probably represent areas of intralesional hemorrhage.
This high power photomicrograph of a core biopsy demonstrates pleomorphic cells and with a blue matrix, suggesting malignant cartilage.
This high power photomicrograph of a core biopsy reveals cellular pleomorphic cells with numerous mitotic figures and small areas of typical tumor new bone. This was typical of most of the biopsy samples. This tissue was interpreted as high grade osteosarcoma cartilage, as is often found in osteosarcomas. This was classified as Osteogenic Sarcoma IIB (high grade outside the compartment).
CT scan of the chest was normal, the total body bone scan revealed only increased uptake in the distal femur.
These radiographs were made shortly after wide resection and prosthetic reconstruction was performed. It is to be noted that epiphysiodesis of the opposite distal femoral epiphysis was done about ten months later to minimize limb length discrepancy.


Patient is doing well at 1.5 years post operatively.

Learning Issues: This lesion is high grade, and has spread outside the compartment. It is diagnosed as Osteosarcoma IIB.

The initial routine radiographs demonstrate only subtle changes; the proper diagnosis could easily have been missed from the routine radiographs.

The accepted treatment today for nonmetastatic osteosarcoma (as in this case) is chemotherapy, multiple drugs, and wide resection limb sparing surgery. The expected results are 60-70% survival and good function at ten years. The reconstruction could include large allografts, prosthetic reconstructions or rotationplasty.

Images of Musculoskeletal Oncology
University at Buffalo Department of Orthopaedics