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Location of the lesion
Extent of the lesion
What is the lesion doing to the bone?
What is the bone doing to the lesion?
Hint as to its tissue type / matrix
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Location and age of patient most important
parameters in classifying a primary bone
tumor.
Simple to determine from plain radiographs.
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EPIPHYSEAL
◦ Chondroblastoma
◦ Clear cell
chondrosarcoma
◦ Giant cell tumor
◦ Aneurysmal bone
cyst
◦ Geode
(subchondral cyst)
◦ Infection
◦ Eosinophilic
granuloma
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METAPHYSEAL
◦ Nonossifying fibroma
(close to growth plate)
◦ Chondromyxoid
fibroma (abutting
growth plate)
◦ Solitary bone cyst,
ABC, GCT
◦ Osteochondroma
◦ Brodie abscess
◦ Osteogenic sarcoma,
chondrosarcoma
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DIAPHYSEAL
◦ Adamantinoma
◦ Leukemia,
Lymphoma,
Reticulum cell
sarcoma
◦ Ewing sarcoma
◦ Metastasis
◦ Osteoblastoma/
osteoid osteoma
◦ Nonossifying
fibroma
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Central: Enchondroma
Eccentric: GCT, CMF,
osteosarcoma
Cortical: osteoid osteoma,
NOF
Parosteal: osteochondroma,
parosteal osteosarcoma
BONE TUMOR
SBC
ABC, GCT, Osteosarcoma
Enchondroma
Osteochondroma
Chondroblastoma
Ewing’s
Adamantinoma
Myeloma
Fibrous dysplasia
Osteoid osteoma
Chordoma
Ivory osteoma
Chondromyxoid fibroma
Chondroblastoma
Osteoblastoma
COMMONEST SITE
Proximal humerus > prox. Femur
Lowerend femur > upper end tibia
Metaphysis of small bones of hand & feet
Distal femur> prox. Tibia > prox. Humerus
Proximal humerus> prox femur
Femur > fibula > tibia
Mandible > tibia
Vertebra
Ribs > Upper femur > Tibia > lower femur
Femur > tibia
Sacrum > clivus (spheno occipital) > anterior
vertebral body
Frontal sinus
Tibia > femur
Pelvis > femur
Posterior spine
Patterns of bone destruction:
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•GEOGRAPHIC
Well-defined smooth / irregular margin
Short zone of transition
•PERMEATIVE
Poorly demarcated lesion imperceptibly
merging with uninvolved bone
Long zone of transition
•MOTHEATEN
Areas of destruction with ragged borders.
Less well defined / demarcated lesional margin
Longer zone of transition
Lytic
Sclerotic
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Margin between tumor and native bone is
visible on the plain radiograph.
Slowly progressive process is “walled-off” by
native bone, producing distinct margins.
Rapidly progressive process destroys bone,
producing indistinct margins.
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Margin types 1A, 1B, 1C, 2, and 3
◦ least aggressive 1A, to most aggressive 3
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Aggressive lesions destroy bone.
Aggressiveness increases likelihood of
malignancy.
◦ BUT, not all aggressive processes are malignant.
◦ AND, not all malignant diseases are aggressive.
A well circumscribed lesion
with a narrow zone of
transition
increasing aggressiveness
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simple cyst (UBC)
enchondroma
FD
chondroblastoma
GCT
chondrosarcoma
(rare)
MFH (rare)
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GCT
enchondroma
chondroblastoma
myeloma,
metastatsis
CMF
FD
chondrosarcoma
MFH
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chondrosarcoma
MFH
osteosarcoma
GCT
metastasis
infection
EG
lymphoma
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myeloma,
metastases
infection
EG
osteosarcoma
chondrosarcoma
lymphoma
Multiple scattered holes that vary in
size & seem to arise separately
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Ewing
EG
infection
myeloma,
metastasis
lymphoma
osteosarcoma
Poorly demarcated from normal, numerous
elongated holes/slots in cortex, run parallel to
long axis of bone
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Limited responses of bone
Destruction:
Reaction:
Remodeling:
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lysis (lucency)
sclerosis
periosteal reaction
Rate of growth determines bone response
◦ slow progression, sclerosis prevails
◦ rapid progression, destruction prevails
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Periosteal reaction must mineralize to be
seen on X ray ( 10 days – 3 weeks)
Configuration of periosteal reaction
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Nature of inciting process
Intensity
Aggressiveness
Duration
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Thick, uninterrupted
◦ long standing process, often non-aggressive
 stress fracture
 chronic infection
 osteoid osteoma
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Spiculated, lamellated
◦ aggressive process
◦ tumor likely
periosteal reaction
Codman
Triangle
advancing tumor margin
destroys periosteal new
bone before it ossifies
tumor
Sunburst Appearance
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“Matrix” is the internal tissue of the tumor
Most tumor matrix is soft tissue in nature.
◦ Radiolucent (lytic) on x-ray
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Cartilage matrix
◦ calcified rings, arcs, dots (stippled)
◦ enchondroma, chondroblastoma, chondrosarcoma
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Ossific matrix
◦ osteosarcoma
 Exostosis: well defined bony
projection growing away from
physis
 Cartilage maybe calcified if
lesions are large / malignant
change
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Nidus: a tiny radiolucent area
If in diaphysis surrounded by dense bone and thickened cortex
Metaphysis less cortical thickening
Double density sign on bone scan – increased uptake in nidus and
decreased uptake in reactive sclerotic zone (also seen in Brodie’s abcess)
Lytic nidus surrounded by sclerotic bone in CT
Centre of nidus may be calcified
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Well demarcated osteolytic lesion sometimes
containing flecks of calcification
Less reactive bone than osteoid osteoma
Bone scan - intense activity
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Cystic radiolucency on the diaphysial side of the growth plate
Cortex may be thinned and bone expanded with well defined thin
sclerotic margin
May have pseudo-loculated appearance secondary to irregular
cortical thinning and thin septal ridges
Falling fragment sign typical and the lesion is never wider than
epiphysial plate
Bone scan cold or minimal activity unless fractured
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Gross honey comb lesion
Often eccentrically placed
Does not extend to the joint (unlike GCT)
Warm to hot on bone scan
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Usually well defined geographic lytic lesion
in the epiphysis/metaphysis extending up to
the joint surface without marginal sclerosis
Junction with normal bone often poorly
defined
Cortex thinned and sometimes ballooned
Bone scan warm to hot
Fibrous cortical defect
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Margin well defined, sometimes scalloped
and often sclerosed
Non-ossifying Fibroma
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Ground glass appearance typical
Shepherds crook deformity of proximal femur
Variable appearance with expansion of cortex
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Scalloped erosions on endosteal surface
May have flecks of calcification
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Rounded or oval rare area
Usually eccentrically placed
May cross the growth plate
Sharp outline and sclerotic rim
Scalloped margin and thin cortex
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Well defined area of rarefaction eccentrically placed in
the epiphysis or across the growth plate
No reaction in surrounding bone
50% show central calcification, 50% show linear
periosteal reaction
Bone scan increased uptake at margins
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Multiple loose bodies
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Large osteolytic lesion in the midline
May contain flecks of calcification
Marked bone destruction
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Diffuse
osteopenia with
multiple
osteolytic lesions
dispersed
throughout
skeleton.
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Characteristic honey comb appearance in
diaphysis
Cortical thinning with expansion
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Vertical striations without bone expansion
and coarse trabecular appearance (corduroy
appearance)
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Mottled lytic defect usually no
sclerotic rim
May destroy cortex
Usually endosteal or periosteal
reaction
Lesions in flat bones and ribs
appear punched out
May appear loculated due to sparing
of large trabeculae
Spinal lesions- collapse (vertebra
plana), which may heal
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Mottled or moth eaten lesion
diffusely involving bone
Lytic destruction common, often the
cortex is perforated
Onion skin appearance- layers of
periosteal new bone are said to be
characteristic
May form Codman’s triangle
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Variable with combination of bone destruction and bone
formation
Sun ray spicules/ sun burst appearance and Codman’s triangle
may be evident
Cortical breach common
Adjacent soft tissue mass
Joint space rarely involved
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25% Lytic
35% Sclerotic
40% Mixed
Telangiectatic type- purely lytic
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Variable appearance with 60 - 70% have calcification
and 50% have sub periosteal new bone
May be a large cystic lesion with cortical destruction
and central calcification, endosteal scalloping and
cortical expansion; annular, punctate or comma
shaped calcification
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Bone often mottled or moth eaten
with extension into soft tissue
Osteolytic lesion may be
surrounded by reactive bone
Destructive appearance
radiologically
Usually little periosteal reaction
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Osteolytic commonest - cortical destruction with
little or no periosteal reaction; Lungs, Kidney,
Adrenal, Thyroid, Uterus
Osteoblastic deposits – Prostate, Bladder, Testis,
Breast and Bowel secondaries. Also carcinoid
lung tumors, lymphoma
Mixed- Breast, Lung, Ovary, Cervix
Lymphoma deposits may resemble prostatic
deposits, i.e. sclerotic secondaries
Lytic, expansile, with soft tissue mass- RCC,
thyroid
X-Ray- at least 50% loss of bone to produce lysis
on X-ray, Loss of single pedicle produces a
“winking owl sign”. CT scan, MRI
Osteolytic bone metastases:
breast carcinoma shows multiple osteolytic bone lesions.
Osteoblastic bone metastases
Mixed pattern bone metastases:
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Early - vague mottled lucent areas
Diffuse destructive lytic lesion with little
periosteal reaction
Usually combination of patchy sclerosis and
mottled destruction
Hogkins disease - typical appearance of ivory
vertebrae
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May be generalised decrease in bone density
Multiple punched out defects
Little bony reaction around lesions
Solitary lesion = plasmacytoma; multilocular expanding lytic
lesion in a red marrow area
Frequently cold on bone scan