Malignant Bone Tumors

Overview

Ewing Sarcoma

• Introduction 
  • anaplastic small blue cell tumor 
    • neuroectoderm origin
    • involves an 11;22 translocation  
  • boys < 15 has highest incidence
  • most often seen in diaphysis of long bones, pelvis, scapula, and ribs
• Evaluation
  • layered “onion-skin” deposition of bone 
• Prognosis, Prevention, and Complications
  • early metastasis
• responsive to chemotherapy

Chondrosarcoma

• Introduction
  • malignant cartilaginous tumor
  • seen in men 30-60 years
  • most commonly involves the central skeleton
  • may occur de novo or from progression of osteochondroma
• Evaluation 
  • expansile glistening mass 
• located in the medullary cavity

Osteosarcoma (osteogenic sarcoma)

• Introduction
  • tumor of osteoblasts
  • most common primary malignant tumor of bone
  • commonly found in the metaphysis of long bones
    • e.g. distal femur or proximal tibia
  • risk factors
    • Paget disease of bone 
      • results in onset in elderly
    • bone infarcts
    • radiation
    • familial retinoblastoma
      • Rb mutation
      • results in onset before third decade
• Evaluation
  • histology 
    • large pleomorphic cells producing increased osteoid 
  • Radiograph 
    • Codman’s triangle or sunburst pattern 
      • from elevation of periosteum from the cortical bone
• Prognosis, Prevention, and Complications
• poor prognosis

Bone Metastasis

• Introduction
  • typically result in osteolytic lesions
  • exception is prostatic carcinoma
    • produces osteoblastic lesion