Orthopaedic Oncology cases osteosarcoma

A 66-year-old man with history of retinoblastoma presents with right knee pain. AP and lateral radiographs are shown in Figure 8–14A and B.

 

Figure 8–14 A–B

What is the most likely diagnosis?

1. Ewing sarcoma

2. Osteonecrosis

3. Osteomyelitis

4. Osteosarcoma

 

Discussion

The correct answer is (D). These x-rays reveal a bone-producing lesion in the distal femoral metadiaphysis. There is periosteal elevation and soft-tissue mass, consistent with osteosarcoma. The patient’s history of retinoblastoma represents predisposition to osteosarcoma.

The patient asks about treatment recommendations. Which of the following is an accurate statement regarding management of his condition?

1. The standard treatment is neoadjuvant chemotherapy, followed by surgical resection, followed by additional adjuvant chemotherapy

2. The lesion is exquisitely radiosensitive, and management is therefore centered around radiation therapy only

3. Bone biopsy must be performed to isolate the infectious organism, and then targeted IV antibiotic therapy must be administered for 6 to 8 weeks

4. External beam radiation therapy should be performed prior to surgery, to minimize radiation dose and size of the field

Discussion

The correct answer is (A). The standard of care of classic osteosarcoma is chemotherapy, surgical resection (either limb-sparing surgery or amputation) followed by adjuvant chemotherapy. There is no role for radiation in the standard treatment of osteosarcoma. Choice C would be appropriate for osteomyelitis of the distal femur, however, x-rays shown are more consistent with malignancy as opposed to an infectious process.

Among other chemotherapeutic agents, doxorubicin is selected by the medical oncologist. What is the major toxic side effect of this drug?

1. Renal failure

2. Mucositis

3. Cardiotoxicity

4. Encephalopathy

Discussion

The correct answer is (C). Doxorubicin is a critical agent in the chemotherapeutic treatment algorithm for osteosarcoma. However, the potential for cardiotoxic side effects must be monitored. Methotrexate is associated with mucositis, ifosfamide is associated with renal failure and encephalopathy, and cisplatin is associated with neuropathy, hearing loss, and renal failure. Depending on the medical status of the patient, these drugs are commonly used individually or in combination for adjuvant chemotherapy for osteosarcoma.

 

Objectives: Did you learn...?

 

Treatment and clinical/radiographic identification of osteosarcoma?