Are bone tumors common?
Not in comparison to carcinomas and hematopoietic tumors
Malignant bone tumors comprise (0.2%) of all types of cancer
How do bone tumors commonly present?
What are some diagnostic factors to think about with bone tumors?
Skeletal localization: specific bone, specific area of bone
What age do Osteosarcoma, Ewing's sarcoma generally affect?
What ages do giant cell tumors generally affect?
What ages do Chondrosarcomas generally affect?
What is a slcerotic margin an indication of?
Benign, slowly-growing neoplasm
What is an ill-defined margin indicative of?
Malignant, rapidly-growing neoplasm
What does it mean to see solid, ivory-like patterns on radiographs of bone?
Generally seen in malignant bone matrix-forming tumors
What does it mean to see rings and arcs on radiographs of bone?
Generally seen in chondroid matrix-forming tumors
What is the most common primary bone tumor?
Benign bone-forming tumors
Osteoid Osteoma & Osteoblastoma
Histologically very similar
Located in long bones, femur & tibia
Responds to aspirin
Radiolucent lesion within sclerotic cortex
Located in vertebrae or long bone metaphysis
Not responsive to aspirin
Expansile radio-lucency with mottling
Malignant mesenchymal tumor in which cells produce osteoid or bone
35% of bone sarcomas
What population does osteosarcoma generally affect?
Mean age: 15 (60% 10-20)
2nd peak: 55-80
Where does osteosarcoma usually reside?
Metaphysis of long bones (femur, tibia, humerous; flat bones, spine - older pts)
May be polyostotic -- multiple bone sites (not common)
Hematogenous spread to lungs is common
Where does osteosarcoma commonly spread hematogenously?
To the lungs
What are some characteristics that may predispose someone to osteosarcoma?
- Inherited mutant allele of RB gene: marked increased (1000X) in OS
- Mutation of p53 suppressor gene: Li-Fraumeni
- Overexpression of MDM2 (5-10%); INK4 and p16
- Sites of bone growth/disease (Paget's)
- Prior irradiation
What are some radiographic findings that are commonly indicative of osteosarcoma?
- Poorly delineated
- Bone destruction
- Cortical disruption
- Bone matrix
- Soft tissue extention
- Codman's triange: radiographic sign, rapidly growing mass with periosteum trying to grow around it
What is found pathologically with osteosarcomas?
Infiltrative tumor, extending into soft tissue
Malignant cells producing osteoid
What is the treatment for osteosarcoma?
Neo-adjuvant chemotherapy and surgical resection (amputation)
What was the prognosis for Osteosarcoma prior to 1970? What is it now, after the advent of chemotherapy?
Prior to 1970: 5 year survival 20%; most relapsed in lung within 6 months after primary amputation; mets to lung pleura, other bones, CNS
Post chemotherapy: 60-65% 3-5 year survival for patients with non-metastatic disease; En-bloc resection following chemotherapy: >90% necrosis -- near 90% survival
Most common benign tumor of bone
Where are osteochondromas commonly located in bones?
Metaphysis of long bones
Is transformation of osteochondroma to malignancy common?
No -- it's rare (<1%) but increased risk in hereditary multiple exostoses --> Autosomal dominant, commonly secondary to mutations in EXT-1 (8q24)
Benign hyaline cartilage lesion (2 kinds)
Enchondroma = intramedullary chondroma
Periosteal chondroma = juxtacortical chondroma (located on the cortical surface under the periosteum)
How do enchondromas usually present?
Usually asymptomatic, incidental finding.
Appendicular skeleton; small bones of hands and feet.
How do enchondromas appear on x-ray? In microanalysis?
X-ray: lytic, lobulated, cortical thinning
Micro: lobules of hyaline cartilage, minimal atypia
How are enchondromas treated?
Nothing! Unless lesion shows changes:
1. become symptomatic
2. evidence of recent growth after skeletal maturity