Bone Tumors Flashcards
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?
Usually non-specific:
Pain
Mass
Pathologic fracture
Asymptomatic
What are some diagnostic factors to think about with bone tumors?
Age
Sex
Skeletal localization: specific bone, specific area of bone
Radiographic appearance
What age do Osteosarcoma, Ewing’s sarcoma generally affect?
Childhood, adolescence
What ages do giant cell tumors generally affect?
Young adults
What ages do Chondrosarcomas generally affect?
Elderly
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?
Osteochondroma
Benign bone-forming tumors
Osteoid Osteoma & Osteoblastoma
Histologically very similar
Located in long bones, femur & tibia
<2cm
Night pain
Responds to aspirin
Radiolucent lesion within sclerotic cortex
Osteoid Osteoma
Located in vertebrae or long bone metaphysis
>2cm
Painful
Not responsive to aspirin
Expansile radio-lucency with mottling
Osteoblastoma
Malignant mesenchymal tumor in which cells produce osteoid or bone
35% of bone sarcomas
Osteosarcoma
What population does osteosarcoma generally affect?
M>F
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
Osteochondroma
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:
- become symptomatic
- evidence of recent growth after skeletal maturity
What can lead to Multiple Chondromatosis?
Frequent point mutations in IDH1 or IDH2
Ollier’s disease: multiple enchondromata, tend to have regional distribution, could have severe skeletal malformation
Maffucci’s syndrom: multiple enchondromata + angiomata, severe skeletal malformation, higher incidence of malignant transformation
Malignant tumor in which neoplastic cells produce a purely carilaginous matrix
2nd most common bone sarcoma (~26%)
Chondrosarcoma
What population do Chondrosarcomas commonly affect?
Wide range of ages, mainly older adults (mostly 40-50 years)
Peak at 6-7th decades
Where do chondrosarcomas generally occur?
Pelvis and ribs (45%); humerus, femur (metaphysis, diaphysis)
What do chondrosarcomas look like on radiographs?
Medullary location
Frequently present calcifications, which tend to be lost in grade 3 tumors
Cortical erosion or destruction
Occasional soft tissue extension
“Popcorn-like appearance”
How do chondrosarcomas appear pathologically?
More cellular and nuclei more pleomorphic than enchondromas
Binucleation is frequent but does not suffice for malignant diagnosis
Myxoid change of chondroid matrix
How is grading dictated in chondrosarcomas?
Size (< or > 10 cm) and grade correlate with behavior
Grading (1-3) based on degree of cellularity and atypia
What is the prognosis for chondrosarcoma?
Grades 1,2: 80-90%
Grade 3: 29% (pulmonary metastasis)
Variants: de-differentiated, myxoid, clear cell, mesenchymal, juxtacortical
Common developmental cortical defect
Most common space-occupying lesion of bone: 1 of every 4 individuals
Non-ossifying fibroma
What are some common locations for non-ossifying fibromas?
Tibia, femur (metaphysis)
When do non-ossifying fibromas occur in life?
1st-3rd decade
What is the histological appearance called of non-ossifying fibromas?
“Starry-sky”
Developmental arrest of bone
Can be monostotic (most common, in adolescents, ribs, mandible and femur)
Or Polyostotic (in infancy/childhood, crippling deformities, cranio facial involvement common)
Fibrous dysplasia
What is McCune-Albright syndrome? More common in F or M?
Polyostotic fibrous dysplasia with endocrinopathies and cafe-au-lait spots
F>M
Sexual precocity, acromegaly, Cushing syndrome
Genetically, how does McCune-Albright occur?
Activating germline mutations of GNAS (GTP-binding protein) results in excess cAMP leading to endocrine gland hyperfunction
How does fibrous dysplasia appear on x-ray?
- Expansile
- Circumscribed
- Thinned cortex
- “ground glass”
- May be multiple
What does the pathology of fibrous dysplasia look like?
Haphazard, curvilinear, randomly oriented woven bone trabeculae (“chinese characters”), surrounded by fibroblastic stroma
No significant osteoblastic rimming
How do you treat fibrous dysplasia?
Conservative, except polyostotic form
Second most common malignant bone tumor in childhood
Adolescents, young adults; M>F
Present as painful, often enlarging mass
Ewing Sarcoma/ PNET
What part of bone does Ewing Sarcoma affect?
Diaphysis of long tumular bones, ribs, pelvis
How does Ewing Sarcoma appear on X-ray?
Destructive moth-eaten, permeative medullary lesion with large soft tissue mass
“Onion-skin” pattern of periosteal reaction in response to rapid growth
How does Ewing Sarcoma present pathologically?
- Sheets of primitive small round blue cells with neural phenotype
- Membranous CD99
- Contain abundant glycogen
- Hemorrhage and necrosis common
What genetic translocation is associated with Ewing Sarcoma?
t(11;22): EWS on 22q fused wtih FLI-1 transcription factor on 11
Present in 85% of tumors
What is the treatment for Ewing Sarcoma?
Chemotherapy and surgery
Radiation therapy may be added
Stage 1: 5 year survival 70% with chemo/RT
What population do giant cell tumors of bone commonly affect?
Young adults (20-40 years)
Older adolescents (skeletally matured)
F>M
Where do giant cell tumors generally presents?
Epiphyseal location
Knee, proximal humerus, radius
Are giant cell tumors of bone generally malignant or benign?
Most are benign, locally aggressive
May destroy cortex of bone and extend into soft tissue
Are primary or metastatic bone tumors more likely?
Malignant bone tumors are 20x more frequent than primary bone tumors – especially in adults
What are the main types of cancers that are known to cause metastatic bone tumors?
BLT-KP
Breast, Lung, Thyroid, Kidney, Prostate
