• Most common malignant bone tumor in childhood
    • 50% of newly diagnosed malignant pediatric bone tumors
    • boys > girls
    • Peaks ages : 10-19yrs
    • Not different between white/black

Risk factors

  • Mostly unknown
  • Correlate with the growth spurt in teenagers
  • In minority specific risk factor:
    • Prior RT
    • Genetic syndrome
      • Survivors of hereditary retinoblastoma carry a risk of osteosarcoma of 6% at 18 years
      • Li-Fraumeni syndrome
      • Older adults —> Association between Paget's

Clinical Presentation

  • Pain
  • Sometimes after trauma and a subsequent pathologic fracture
  • 90% —> in the diaphysis of the extremities
    • Distal femur & proximal tibia —> most common sites
    • Pelvis
    • Head & neck

Diagnostic Evaluation

  • Plain radiograph
    • Ill-defined zone of transition
    • Codman's triangle
      • Defined as osteoid formation under the periosteum
    • Bone formation in the adjacent soft tissue

Types of lesion

  • Sclerotic
  • Lytic
  • Mixed
  • Magnetic Resonance Imaging
    • Proximal and distal extent of involvement
    • Evaluate any soft tissue component
    • Establish the proximity of nerves, vessels, and the joint space


  • CT
  • Bone Scan
  • PET-scan

Metastasis at diagnosis:

  • ~15%
  • Isolated skip metastases uncommon —> < 5%
  • Mets
    • Lung : > 80%
    • Bone

Staging Systems


WHO classification

  • Intramedullary
  • Surface subtypes
  • Osteoblastic
  • Chondroblastic
  • Fibroblastic
  • Mixed types
  • Small cell
  • Telangiectatic
  • Well-differentiated (or low-grade)

Overall Management


  • Chemotherapy is essential for cure.
  • Chemotherapy —> resection of the primary tumor —> adjuvant chemotherapy

Two randomized studies demonstrated the efficacy of adjuvant chemotherapy

Standard agents used:

  • Methotrexate
  • Cisplatin
  • Doxorubicin
  • +/- Ifosfamide.

A randomized Pediatric Oncology Group study showed no difference in outcome whether preoperative or postoperative chemotherapy was administered

Advantages of neoadjuvant chemotherapy:

  • Determination of the pathologic response
  • Early treatment of micrometastatic disease
  • Allowing adequate time for surgical planning and ordering of a custom prosthesis.

The percent necrosis after neoadjuvant chemotherapy is a prognostic factor

OS based on Huvos grade( amount of necrosis ) :

  • Nonmetastatic disease with >90% necrosis —> OS: 70%
  • <90% necrosis —> OS : 50%



  • Not candidate for surgery
  • Refuse surgery
  • Positive margins after surgery
  • Those with sites that are not amenable to resection and reconstruction
  • Palliation

Modern External-beam Radiotherapy

A median of 60 Gy was given using conventional fractionation.
The 5-year local progression-free survival was 56%, with an overall survival of 61%.
Those with a good response to neoadjuvant chemotherapy had an overall survival of 90%, compared with 35% in those who were poor responders.
This phenomenon was also paralleled in local control. There were no local failures in good responders, but nearly one third of poor responders failed locally.
Not clear that radiotherapy added to the overall outcome.

Extracorporeal and Definitive Intraoperative Radiotherapy

The techniques of extracorporeal and definitive intraoperative radiotherapy (IORT) have been investigated in bone tumors (Table 80.4) (9,15,28,44,58,59). The extracorporeal technique includes en bloc resection of the tumor and surrounding soft tissues, irradiation of the specimen, and reimplantation, often with the aid of prostheses. With definitive IORT, the operative field is exposed and radiotherapy is administered. No resection of the tumor is performed.
Extracorporeal irradiation is associated with a low rate of local recurrence (<5%). Chen et al. (15) noted a higher rate of complications (62%) in their initial series. The events included fractures, nonunions, wound infections, and loss of cartilage. Subsequently, they incorporated the use of prostheses placed at the time of reimplantation. Their local recurrence rate

continued to be low and there was only one complication (a nerve palsy) in their series of 14 patients (15).

Surgical Management

  • En bloc resection with negative margins with reconstruction
  • Amputation should be recommended if the patient will be left with a nonfunctioning limb
  • 80% to 90% —> limb salvage
  • Reconstruction
    • Autologous bone grafts
    • Allografts
    • Endoprosthetics

Side Effects of reconstructions

  • Infections ( endoprosthetics )
  • Nonunion
  • Fracture ( Allograft )

Pelvic osteosarcoma : more challenging