Bone Tumor - Dr. Hanan Hosny

Types of Bone Tumors

• Metastatic carcinomas are the most common type of bone tumor, which originate from other sites, commonly from lung, prostate, and breast carcinomas.

Benign Bone Tumors

• Osteoma is a benign neoplasm that typically affects the skull and facial bones.
• Osteoid osteoma is a benign bone tumor that arises from osteoblasts, commonly occurring between 10-20 years old, and frequently affects the proximal femur, tibia, and humerus.
• Osteochondroma is the most common benign tumor, affecting the metaphysis near the growth plate, capped with cartilage, and is more common in male adolescents.
• Enchondroma is a benign cartilaginous tumor that usually affects the bones of hands and feet, presenting as a well-circumscribed lesion arising from the medullary cavity of bone.

Malignant Bone Tumors

• Osteosarcoma:
  • Most common primary malignant tumor of bone
  • Typically affects teenagers (10-25 years old) and is more common in males
  • Presents with a bony mass with or without pain, and may present with a fracture
  • Tends to occur at the sites of bone growth
  • X-ray findings: Sunburst pattern (hair on end) periosteal reaction and destruction of bone (osteolytic) Codman's triangle: area of sub periosteal new bone formation
  • Prognosis: Poor, with hematogenous spread to lung
• Chondrosarcoma:
  • Malignant tumor of chondroblasts
  • May arise de novo or secondary to Paget's disease
  • Typically affects the pelvic bone, spine, and shoulder girdle
  • Microscopically: Atypical chondrocyte and chondroblast, often with multiple nuclei in a lacuna
• Giant cell tumor:
  • Uncommon benign but locally aggressive, with a tendency to recur
  • Typically affects the joints, causing arthritis-like symptoms
  • X-ray: Lytic mass traversed by thin sclerotic line (soap bubble appearance)
  • Microscopically: Numerous osteoclast-like multinucleated giant cells
• Ewing sarcoma:
  • Primary malignant tumor
  • Affects children, with an average age of presentation between 10-15 years old
  • Arises in the medullary cavity, expanding and destroying the medullary cavity, cortex, and surrounding structures
  • Microscopically: Sheets of uniform small, round cells with small amounts of clear cytoplasm, and Homer-Wright rosettes
  • X-ray: Destructive lesion in diaphysis, infiltrating the cortex from within (onion skin)