Osteosarcoma

• AKA Osteogenic Sarcoma

Definition

• Primary malignant bone-producing bone tumour characterised by production of osteoid
  • ie bone matrix produced by malignant cells

Epidemiology

• Second most common malignant neoplasm of bone after multiple myeloma
• 20% of all malignant neoplasms of bone
• Bimodal peak
  • Teens
  • Elderly
• M:F – 1.5:1

Classification

Anatomical Classification

• 1. Central
  • Further subclassified by
    • Grade
      • High grade (10-20yo, most common)
      • Low grade
    • Pathology
      • Conventional
      • Telangiectatic
      • Small cell
      • Giant cell
• 2. Juxtacortical (surface osteosarcoma)
  • Low grade (30-40yo, usually low grade)
  • High grade
  • Parosteal or Periosteal
• 3. Intra-cortical
• 4. Soft tissue
• 5. Secondary

Aetiology

• Strong genetic influence
  • Increased risk in children with familial retinoblastoma (500x)
  • RB 1 gene on chromosome 13
  • P53 on 17p
• Also associated with chromosomal abnormalities such as
  • Rothmund-Thompson syndrome
  • Bloom syndrome