osteosarcoma[2]

04/12/23

1

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