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Osteosarcoma. Paul Duffy. Definition Epidemiology Pathogenesis Skeletal distribution Clinical presentation Evaluation High grade osteosarcoma. Parosteal osteosarcoma Periosteal osteosarcoma High grade surface osteosarcoma. Overview. Definition. 2 nd most common primary bone tumor
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Osteosarcoma Paul Duffy
Definition Epidemiology Pathogenesis Skeletal distribution Clinical presentation Evaluation High grade osteosarcoma Parosteal osteosarcoma Periosteal osteosarcoma High grade surface osteosarcoma Overview
Definition • 2nd most common primary bone tumor • Malignant tumor of mesenchymal origin • Spindle shaped cells that produce osteoid
Epidemiology • Any age • 75% 12-25yrs • Modal incidence
Epidemiology • Primary vs secondary • Male : female • Li Fraunie syndrome
Pathogenesis • Unknown • Modal incidence correlates with rapid bone growth • Radiation exposure • Cancer survivors • Retinoblastoma
Clinical Presentation • Painful mass arising from bone • Trauma • Metastisize early in evolution • 20% clinically detectable mets at dx
Evaluation • Suspected diagnosis by hx and physical • Supported by xray
Plain Xray • Lytic, sclerotic or mixed • Typical characteristics of malignant tumor • Enneking’s 4 questions
Initial Evaluation • Define the extent of the disease • Locally • Systemically
Local • CT • MRI • +/- Angiogram
Systemic • Bone scan • CT Chest • lab
Classic High Grade Osteosarc • Age, sex • Presentation • Physical exam • Blood work • Plain films • Site • size
Differential Dx • Giant Cell Tumor • Aneursymal Bone Cyst • Ewings • Osteoblastoma • Metastasis • Lymphoma
Biopsy • Principles • Dx “high grade osteosarcoma” • Now What??
Chemotherapy • Micro metastasis • What we have learned pre chemo (1970’s) • Multi Institutional Osteosarcoma Study
Chemotherapy • Chemo cannot control clinically detectable disease • Radiation is ineffective • Local control is surgical
Chemotherapy • Best protocol is subject of ongoing trials • Drugs • Doxorubicin • Cisplatin • Ifosfamide • Methotrexate • Cyclophosphamide • Side effects
Induction Chemotherapy • Arose in conjunction with development of limb sparing surgery • Increase survival • prognostic
Surgery • Limb salvage the norm • Now safer procedure • Wide surgical margin
Surgical options • Articular surface removed • Osteoarticular allograft replacement • Custom modular prosthesis • Allograft prosthesis composite • Allograft arthodesis • Segment of diaphysis missing • Intercalary allograft
Surgery • Young patient with open growth plate • Rotatioplasty • Conventional amputation
Surgery • Indication for amputation • Grossly displaced pathologic fracture • Encasement of neurovascular bundle • Tumor that enlarges during preop chemo and is adjacent to neurovascular bundle
Current Standard of Care • Pretreatment radiologic staging • Bx to confirm diagnosis • Preoperative chemotherapy • Repeat radiologic staging • (access chemo response, finalize surgical tx plan) • Surgical resection with wide margin • Reconstruction using one of many technoques • Post op chemo based on preop response
Surface osteosarcoma • Parosteal • Periosteal • High grade surface osteosarcoma
Parosteal • 5% of osteosarcomas • Posterior metaphysis of distal femur • Slow growing large ossified mass • Confused with osteochondroma • String sign • Low grade • treatment
Periosteal Osteosarcoma • Arises from surface of diaphysis • Characterized by bony spicule formation perpendicular to shaft • Sunburst • Low grade • Wide excision
High grade surface • Very rare • 20-30’s • Appearance as parosteal but histology high grade • Tx as classic intermedullary