Osteosarcoma

1. 06/23/10 1
Osteosarcoma
Paul Duffy

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Overview
Definition
Epidemiology
Pathogenesis
Skeletal distribution
Clinical presentation
Evaluation
High grade
osteosarcoma
Parosteal
osteosarcoma
Periosteal
osteosarcoma
High grade surface
osteosarcoma

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Definition
2
nd
most common primary bone tumor
Malignant tumor of mesenchymal origin
Spindle shaped cells that produce osteoid

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Epidemiology
Any age
75% 12-25yrs
Modal incidence

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Epidemiology
Primary vs secondary
Male : female
Li Fraunie syndrome

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Pathogenesis
Unknown
Modal incidence correlates with rapid bone
growth
Radiation exposure
Cancer survivors
Retinoblastoma

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Skeletal distribution

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Classification

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Clinical Presentation
Painful mass arising from bone
Trauma
Metastisize early in evolution
20% clinically detectable mets at dx

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Evaluation
Suspected diagnosis by hx and physical
Supported by xray

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Plain Xray
Lytic, sclerotic or mixed
Typical characteristics of malignant tumor
Enneking’s 4 questions

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Initial Evaluation
Define the extent of the disease
Locally
Systemically

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Local
CT
MRI
+/- Angiogram

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CT

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MRI

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Angio

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Systemic
Bone scan
CT Chest
lab

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Classic High Grade Osteosarc
Age, sex
Presentation
Physical exam
Blood work
Plain films
Site
size

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Differential Dx
Giant Cell Tumor
Aneursymal Bone Cyst
Ewings
Osteoblastoma
Metastasis
Lymphoma

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Biopsy
Principles
Dx “high grade osteosarcoma”
Now What??

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Chemotherapy
Micro metastasis
What we have learned pre chemo (1970’s)
Multi Institutional Osteosarcoma Study

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Chemotherapy
Chemo cannot control clinically detectable
disease
Radiation is ineffective
Local control is surgical

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Chemotherapy
Best protocol is subject of ongoing trials
Drugs
Doxorubicin
Cisplatin
Ifosfamide
Methotrexate
Cyclophosphamide
Side effects

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Induction Chemotherapy
Arose in conjunction with development of
limb sparing surgery
Increase survival
prognostic

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Surgery
Limb salvage the norm
Now safer procedure
Wide surgical margin

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Surgical options
Articular surface removed
Osteoarticular allograft replacement
Custom modular prosthesis
Allograft prosthesis composite
Allograft arthodesis
Segment of diaphysis missing
Intercalary allograft

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Surgery
Young patient with open growth plate
Rotatioplasty
Conventional amputation

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Surgery
Indication for amputation
Grossly displaced pathologic fracture
Encasement of neurovascular bundle
Tumor that enlarges during preop chemo and is
adjacent to neurovascular bundle

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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

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Surface osteosarcoma
Parosteal
Periosteal
High grade surface osteosarcoma

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Parosteal
5% of osteosarcomas
Posterior metaphysis of distal femur
Slow growing large ossified mass
Confused with osteochondroma
String sign
Low grade
treatment

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Parosteal Osteosarcoma

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Parosteal Osteosarcoma

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Periosteal Osteosarcoma
Arises from surface of diaphysis
Characterized by bony spicule formation
perpendicular to shaft
Sunburst
Low grade
Wide excision

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High grade surface
Very rare
20-30’s
Appearance as parosteal but histology high
grade
Tx as classic intermedullary