2. (1) Location of the lesion
(2) Extent of the lesion
(3) What is the lesion doing to the bone?
(4) What is the bone doing to the lesion?
(5) Hint as to its tissue type / matrix
3. Location and age of patient most important
parameters in classifying a primary bone
tumor.
Simple to determine from plain radiographs.
9. Patterns of bone destruction:
Lytic
Sclerotic
•PERMEATIVE
•GEOGRAPHIC
•MOTHEATEN
Poorly demarcated lesion imperceptibly
merging with uninvolved bone
Long zone of transition
Areas of destruction with ragged borders.
Less well defined / demarcated lesional margin
Longer zone of transition
Well-defined smooth / irregular margin
Short zone of transition
10. 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.
11. Margin types 1A, 1B, 1C, 2, and 3
◦ least aggressive 1A, to most aggressive 3
Aggressive lesions destroy bone.
Aggressiveness increases likelihood of
malignancy.
◦ BUT, not all aggressive processes are malignant.
◦ AND, not all malignant diseases are aggressive.
16. myeloma,
metastases
infection
EG
osteosarcoma
chondrosarcoma
lymphoma
Multiple scattered holes that vary in
size & seem to arise separately
17. Ewing
EG
infection
myeloma,
metastasis
lymphoma
osteosarcoma
Poorly demarcated from normal, numerous
elongated holes/slots in cortex, run parallel to
long axis of bone
18. Limited responses of bone
Destruction: lysis (lucency)
Reaction: sclerosis
Remodeling: periosteal reaction
Rate of growth determines bone response
◦ slow progression, sclerosis prevails
◦ rapid progression, destruction prevails
19. Periosteal reaction must mineralize to be
seen on X ray ( 10 days – 3 weeks)
Configuration of periosteal reaction
◦ Nature of inciting process
◦ Intensity
◦ Aggressiveness
◦ Duration
20. Thick, uninterrupted
◦ long standing process, often non-aggressive
stress fracture
chronic infection
osteoid osteoma
Spiculated, lamellated
◦ aggressive process
◦ tumor likely
24. “Matrix” is the internal tissue of the tumor
Most tumor matrix is soft tissue in nature.
◦ Radiolucent (lytic) on x-ray
Cartilage matrix
◦ calcified rings, arcs, dots (stippled)
◦ enchondroma, chondroblastoma, chondrosarcoma
Ossific matrix
◦ osteosarcoma
25.
26.
27. Exostosis: well defined bony
projection growing away from
physis
Cartilage maybe calcified if
lesions are large / malignant
change
28. 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
29. Well demarcated osteolytic lesion sometimes
containing flecks of calcification
Less reactive bone than osteoid osteoma
Bone scan - intense activity
30. 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
31. Gross honey comb lesion
Often eccentrically placed
Does not extend to the joint (unlike GCT)
Warm to hot on bone scan
32. 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
37. Rounded or oval rare area
Usually eccentrically placed
May cross the growth plate
Sharp outline and sclerotic rim
Scalloped margin and thin cortex
38. 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
43. Vertical striations without bone expansion
and coarse trabecular appearance (corduroy
appearance)
44. 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
45. 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
46. 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
◦ 25% Lytic
◦ 35% Sclerotic
◦ 40% Mixed
Telangiectatic type- purely lytic
47. 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
48. 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
49. 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
54. 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
55. 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
