04/12/23
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Osteosarcoma
Overview2
DefinitionEpidemiologyPathogenesisSkeletal distributionClinical
presentationEvaluationHigh grade
osteosarcoma
Parosteal osteosarcoma
Periosteal osteosarcoma
High grade surface osteosarcoma
Definition3
2nd most common primary bone tumor
Malignant tumor of mesenchymal origin
Spindle shaped cells that produce osteoid
Epidemiology4
Any age75% 12-25yrsModal incidence
Epidemiology5
Primary vs secondary
Male : female
Li Fraunie syndrome
Pathogenesis6
Unknown
Modal incidence correlates with rapid bone growth
Radiation exposure
Cancer survivors
Retinoblastoma
Skeletal distribution7
Classification8
Clinical Presentation9
Painful mass arising from bone
Trauma
Metastisize early in evolution 20% clinically detectable mets at dx
Evaluation10
Suspected diagnosis by hx and physical
Supported by xray
Plain Xray11
Lytic, sclerotic or mixedTypical characteristics of malignant tumorEnneking’s 4 questions
Initial Evaluation12
Define the extent of the disease
Locally Systemically
Local13
CT
MRI
+/- Angiogram
CT14
MRI15
Angio16
Systemic17
Bone scan CT Chestlab
Classic High Grade Osteosarc18
Age, sexPresentationPhysical examBlood workPlain films
Site size
Differential Dx19
Giant Cell TumorAneursymal Bone CystEwingsOsteoblastomaMetastasisLymphoma
Biopsy20
Principles
Dx “high grade osteosarcoma”
Now What??
Chemotherapy21
Micro metastasis
What we have learned pre chemo (1970’s)
Multi Institutional Osteosarcoma Study
Chemotherapy22
Chemo cannot control clinically detectable disease
Radiation is ineffective
Local control is surgical
Chemotherapy23
Best protocol is subject of ongoing trials
Drugs Doxorubicin Cisplatin Ifosfamide Methotrexate Cyclophosphamide
Side effects
Induction Chemotherapy24
Arose in conjunction with development of limb sparing surgery
Increase survival
prognostic
Surgery25
Limb salvage the norm
Now safer procedure
Wide surgical margin
Surgical options26
Articular surface removed Osteoarticular allograft replacement Custom modular prosthesis Allograft prosthesis composite Allograft arthodesis
Segment of diaphysis missing Intercalary allograft
Surgery27
Young patient with open growth plate Rotatioplasty Conventional amputation
28
Surgery29
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 Care30
Pretreatment radiologic stagingBx to confirm diagnosisPreoperative chemotherapyRepeat radiologic staging
(access chemo response, finalize surgical tx plan)Surgical resection with wide marginReconstruction using one of many
technoquesPost op chemo based on preop response
Surface osteosarcoma31
Parosteal
Periosteal
High grade surface osteosarcoma
Parosteal32
5% of osteosarcomasPosterior metaphysis of distal femurSlow growing large ossified massConfused with osteochondromaString signLow gradetreatment
Parosteal Osteosarcoma33
Parosteal Osteosarcoma34
Periosteal Osteosarcoma35
Arises from surface of diaphysisCharacterized by bony spicule formation
perpendicular to shaftSunburstLow grade Wide excision
High grade surface36
Very rare20-30’sAppearance as parosteal but histology high
gradeTx as classic intermedullary