Imaging of Bone Tumors

1. SHER-I-KASHMIR INSTITUTE OF MEDICAL
SCIENCES
SOURA
DEPARTMENT OF RADIODIAGNOSIS &
IMAGING

2. PRESENTATION BY
Dr Junaid Kazimi
1ST YEAR PG STUDENT

4. CONTENTS
 Introduction
 Epidemiology
 Classification of Bone Tumors
 Principles of Detection and Diagnosis
 Computed Tomography of Bone Tumours
 Magnetic Resonance Imaging
 Ultrasonography

5. K E Y P O I N T S
 Primary bone tumors are rare;non-neoplastic
conditions, metastatic disease, and
lymphohematologic malignancies, which may
simulate primary bone tumors, by far outnumber
genuine bone tumors.
 Excluding myeloma and lymphoma, malignant
primary bone tumors constitute only 0.2% of all
malignancies in adults and approximately 5% of
childhood malignancies.

6. Epidemiology
 The vast majority of primary bone tumors are benign
and since many are non-symptomatic they remain
undetected or are detected only incidentally at
radiographic examinations for other reasons. The true
incidence of benign bone tumors has therefore been
difficult to determine.
 The incidence of primary bone malignancies is in
contrast, fairly well documented in various national
cancer registries

7. Primary bone malignancy Frequency (%)
Osteosarcoma 35.1
Chondrosarcoma 25.8
Ewing’s sarcoma 16.0
Chordoma 8.4
Malignant fibrous histiocytoma 5.7
Angiosarcoma 1.4
Unspecied 1.2
Other 6.4

8. Classification of primary benign bone tumors, peak age, and most
common sites distribution
 The histologic classification of bone tumors is based
on cytologic findings (in particular cell type such as
osteocyte/osteoblast, chondrocyte/chondroblast,
osteoclast,etc.), architecture, and type of matrix
produced by the tumor.
 Despite the rarity of bone tumors there is a very wide
spectrum of entities with sometimes overlapping
features; the current WHO classification (2002)
includes a total of 45 main bone tumor types.

9. Histologic type Peak age (years) Most common sites
Cartilage tumors
Osteochondroma 10–30 Distal femur, proximal tibia,
proximal humerus, rarely
from
flat bone
Enchondroma 10–40 Hands, feet, long tubular
bones
Periosteal chondroma 10–40 Proximal humerus, distal
femur,
hip region, and pelvis
Chondroblastoma 10–30 Distal femur, proximal tibia
and humerus,calcaneus
Chondromyxoid broma 10–30 Proximal tibia, distal femur,
pelvis, feet (metatarsal)

10. Osteogenic tumors
Osteoid osteoma 5–25 Proximal femur, any long
bones
Osteoblastoma 10–40 Spine, long tubular bones,
jaws
Fibrogenic tumors
Desmoplastic fibroma 10–30 Mandible, femur, pelvis
Fibrohistiocytic tumors
Benign fibrous histiocytoma 20–60 Pelvis, femur
Giant cell tumor 20–45 Distal femur, proximal tibia,
distal radius, sacrum

11. Vascular tumors
Hemangioma (cavernous,
capillary, epithelioid, etc.)
usually adults Craniofacial bones, vertebrae
Angiomatosis,
lymphangioma(tosis)
Often children Highly variable
Glomus tumor Usually adults Hands, distal phalanx
Hemangiopericytoma Usually adults Pelvis
Epithelioid hemangioendo-
thelioma
Adults Long tubular bones, spine
Soft tissue type tumors
Lipoma
Schwannoma
Leiomyoma
Adults Femur, calcaneus
Sacrum, mandible
Mandible, tibia

12. Classication of primary
malignant bone tumors, peak
age, and most common sites
distribution

13. Histologic type Peak age (years) Most common sites
Chondrosarcoma
Primary 50–80 Pelvis, proximal/distal
femur,
proximal humerus, ribs
Secondary 20–60 Ex osteochondroma(tosis):
pelvis, hip and shoulder
Dedifferentiated
chondrosarcoma
50–70 Pelvis, femur, humerus
Clear cell chondrosarcoma 25–60 Proximal femur, humerus
Mesenchymal
chondrosarcoma
10–40 Jaws, ribs, pelvis, spine

14. Osteosarcoma
Conventional 10–30 Distal femur, proximal tibia,
hip and shoulder
Telangiectatic osteosarcoma 10–30 Femur, tibia, humerus
Low-grade central
osteosarcoma
20–40 Distal femur, proximal tibia
Parosteal osteosarcoma 20–50 Posterior distal femur,
proximal humerus
Periosteal osteosarcoma 10-30 Femur, tibia
High-grade surface 10–40 Distal femur, shoulder

15. Secondary osteosarcoma
Paget’s associated 50–90 Pelvis, hip and
shoulder,
craniofacial
Post-radiation 50–80
Pelvis, craniofacial, hip
and
shoulder, chest wall
Other conditions 40-70 Bones aected by FD,
bone
infracts, chronic
osteomyelitis,
Ewing´s sarcoma, PNET 5–30 Pelvis, longbones of
lower and
upper extremities
Fibrosarcoma, MFH,
spindle cell sarcoma
40-70 Knee, hip and shoulder
regions, pelvis
Malignant giant cell tumor 20-60 Knee region, pelvis,
shoulder

16. Histologic type Peak age (years) Most common sites
Angiosarcoma 20–70 Spine, pelvis, hip and
shoulder
Other so tissue type
sarcomas
20–70 Long bones, around major
joints
Adamantinoma 10-40 Tibia, rarely ulna, radius and
fibula

17. Classification of most
common conditions
simulating primary
bone tumors, peak
age, and common sites

18. Histologic type Peak age (years) Most common sites
Aneurysmal bone cyst 5–20 Femur, tibia,
humerus,vertebrae
Simple bone cyst Infancy to 20 In childhood: proximal
femur, humerus and tibia
In adults: calcaneus, ilium
Fibrous dysplasia 5–30 Long bones, jaws, skull, ribs
Non-ossifying fibroma 5–20 Distal femur, proximal and
distal tibia
Osteofibrous dysplasia Infancy to 20 Tibia
Langerhans cell
histiocytosis
Infancy to 30 Skull, femur, pelvis,mandible
Pigmented villonodular
synovitis
10–40 Localized: fingers
Diffuse: knee, hip, ankle
Synovial chondromatosis 20–40 Knee, hip
Paget’s disease 50–90 Pelvis, craniofacial bones,

19. Principles of Detection and
Diagnosis
 The majority of bone tumours are detected using
conventional radiographs.
 Occasionally occult lesions may be detected using more
sensitive techniques such as bone scintigraphy and MR
imaging
 Careful analysis of the pattern of bone destruction,
periosteal reaction and matrix mineralisation on
radiographs allow for characterisation of many bone
tumours.
 Additional factors that should be included in determining
the likely diagnosis include the age of the patient, location
of the tumour in bone and any history of a pre-existing
bone abnormality, e. g. Paget’s disease

20. Diagnosis
 Before assessing the imaging the prudent radiologist
should establish some basic facts regarding the patient
 Age
 Gender
 Ethnic and geographic origin.
 Family history
 Past medical history
 Multiplicity
 Serology

21. Age.
 The age of the patient is arguably the single most
useful piece of information as it frequently influences
the differential diagnosis
 Many musculoskeletal neoplasms exhibit a peak
incidence at different ages
 Jack Edeiken(skeletal radiologist), reasonably claimed
that approximately 80% of bone tumours could be
correctly diagnosed on the basis of age alone.

22. Ages 0 10 20 30 40 50 60 70
Simple bone cyst
Fibrous cortical defect
Nonossifying fibroma
Eosinophilic granuloma
Aneurysmal bone cyst
Chondroblastoma
Ewing’s sarcoma
Osteosarcoma
Parosteal osteosarcoma

23. 0 10 20 30 40 50 60 70
Chondromyxoid fibroma
Osteoblastoma
Osteochondroma
Osteoid osteoma
Enchondroma
Giant cell tumor
Malignant fibrous
histiocytoma
Chondrosarcoma
Metastatic lesions
Myeloma

24. Gender.
 In the individual case gender does not play a
significant role in formulating the differential
diagnosis
 When looking at large series of patients with different
types of bone tumor it can be seen that many occur
slightly more commonly in boys.

25. Ethnic and geographic origin
 Ewing’s sarcoma is prevalent in Caucasians but is
rarely seen in the Afro -Caribbean races
 Non-neoplastic bone conditions that may on occasion
simulate neoplasia also show a racial predisposition,
e.g. sickle cell,Gaucher’s and Paget’s diseases
 Osseous TB can mimic a bone tumour and is seen
commonly in developing countries

26. Family history
 Little evidence of a familial predisposition to the
formation of musculoskeletal neoplasms in most
instances.
 The exceptions are certain hereditary bone
conditions that may be found in association with
malignant change,inlude:
 Ollier’s disease and Mafucci’s syndrome
 congenital retinoblastoma
 Rothmund–Thomson syndrome.

27. Serology.
 Abnormal serological tests, such as raised erythrocyte
sedimentation rate (ESR) and white cell count, together
with the examination findings of a hot swollen limb, are
highly suggestive of a bone or so tissue infection. Ewing’s
sarcoma, however ,is notorious for presenting with similar
clinical and serological findings.
 The brown tumor of hyperparathyroidism may mimic a
true bone tumor on both imaging and histology. Raised
serum calcium and alkaline phosphatase levels should alert
the clinician to the possibility of this diagnosis.
 Raised prostatic serum antigen level in an elderly male
patient presenting with a bone-forming tumour is highly
suggestive of a prostate metastasis.

28. Radiographic Diagnosis
The radiograph remains the most
accurate of all the imaging techniques
currently available in determining the
differential diagnosis of a bone lesion.
Two ways:
“Aunt Minnie approach”
Pattern analysis

29. “Aunt Minnie approach”.
 This epithet was attributed by the late Ben Felson to Ed
Neuhauser, Chief of Radiology at the Boston Children’s
Hospital over half a century ago.
 It consists of a question and answer:
 Q:“How do you know that woman is your Aunt Minnie?”
 A: “Because I’ve seen her before and it looks like her”
 This approach relies on familiarity with the typical overall
appearances of a particular lesion.
 This is all very satisfactory if the abnormality under
investigation is classic in appearance, but problems arise if
the lesion has atypical features, arises at an unusual site or
is mimicked by a differing pathology.

30. Pattern analysis
 Relies on meticulous recognition of various
radiographic signs.
 Analysis can be best illustrated by answering a
series of five questions:
 Which bone is affected?
 Where in that bone is the lesion located?
 What is the tumour doing to the bone (pattern of
destruction)?
 What form of periosteal reaction, if any, is
present?
 What type of matrix mineralisation, if any, is
present?

31. Site in Skeleton
 Most bone tumours and infections occur around the knee and in
the proximal humerus, and as such, little diagnostic information
can be deduced from noting the affected bone in many cases.
 Notable exception:
 Benign cartilagenous tumors: hands and feet
 Osteo fibrous dysplasia and adamantinoma : classically involve the
diaphysis of the tibia and are extremely rare at any other site
 Medial third of the clavicle in children and adolescents:
osteomyelitis or part of the spectrum of chronic recurrent
multifocal osteomyelitis.

32. •Most lesions arising in the sternum are malignant
• Chordoma characteristically arises from the clivus
or sacrum.
•Many different tumours may arise in the bony
spine, malignant lesions are found predominantly
in the anterior part of the vertebra (body), while
benign lesions, with a few exceptions, are
characteristically found in the posterior elements
•Most spinal infections develop first in the
vertebral endplate and rapidly extend to involve the
disc space, which is uncommon in neoplasia.

33. Osteobrous
dysplasia (OFD) tibia
Lateral radiograph
shows a typical mildly
expansile lytic lesion
arising in the
anterior cortex of the
diaphysis. This is the
typical site for OFD
and adamantinoma;
both are rare at other
skeletal sites

34. Location in Bone
 The site of the original bone tumour is an important
parameter of diagnosis. It reflects the site of greatest
cellular activity.
 During the adolescent growth spurt the most active
areas are the metaphyses around the knee and the
proximal humerus.
 Tumour originating from marrow cells may occur
anywhere along the bone
 Conventional osteosarcoma will tend, therefore, to
originate in the metaphysis or meta-diaphysis

35. Osteosarcoma
femur
Lateral radiograph shows some ill-defined
sclerosis in the distal femoral metaphysis due to
malignant osteoid.

36. Ewing’s sarcoma will
arise in the metaphysis
or, more distinctively,
in the diaphysis
Ewing’s sarcoma
in the femur. AP
radiograph
shows the classical
diaphyseal location,.

37. In the child the differential diagnosis of a lesion arising within
an epiphysis can be realistically limited to:
1.Chondroblastoma
2. epiphyseal abscess (pyogenic or tuberculous) and
3. Langerhans cell histiocytosis
Following skeletal fusion subarticular lesions, analogous in the
adult to the epiphyseal lesions in children, include:
1. giant cell tumour
2.clear cell chondrosarcoma (rare)
3. intraosseous ganglion
With the exception of epiphyseal abscess most osteomyelitis
will arise within the metaphysis of a long bone, typically the
tibia and femur.

38. Chondroblastoma tibia. a AP
radiograph shows a lytic lesion
arising in the proximal tibial epiphysis.

39. Location in Bone
It is also helpful to identify the origin
or epicentre of the tumour with respect
to the transverse plane of the bone.
 central,
 Eccentric or
Cortically based

40. central
 simple bone cyst,
 fibrous dysplasia
 Ewing’s sarcoma
Fibrous dysplasia tibia. AP radiograph shows
typical features being well defined and central,
mildly expansile with a ground-glass density
matrix

41. eccentric
 Giant cell tumour
 Chondro myxoid fibroma
 Non-ossifying fibroma
AP radiograph shows a lytic, eccentric,
subarticular lesion

42. Non-ossifying
fibroma tibia
AP radiograph
shows a typical
example with a well-
defined sclerotic
margin arising in an
eccentric location
complicated by a
pathological
fracture

43. cortically
based
 Benign:
Periosteal chondroma
Juxtacortical chondroma.
 Malignant:
Periosteal
High grade surface
and Parosteal osteosarcoma

45. summary
 Analysis of the location of a tumour in bone should,
therefore, recognize the position in both the longitudinal
and transverse planes.
 Combining these factors can then help to narrow down the
differential diagnosis.
 Examples:
 A Giant cell tumour will be subarticular and eccentric,
whereas both non-ossifying fibroma and chondromyxoid
fibroma will tend to be metaphyseal and eccentric in
location
 In the sacrum, chordoma classically arises in the midline,
whereas giant cell tumour, a not uncommon tumour in the
sacrum at a similar age, will be eccentric bordering on one
of the sacroiliac joints, i.e. subarticular in origin.

46. The typical
sites of bone
tumours. MFH
malignant
brous
histiocytoma,
ABC
aneurysmal
bone cyst

47. Pattern of Bone Destruction
 Bone destruction is usually the first radiographic sign of disease and may
be the only evidence of pathology.
 Trabecular bone is more easily destroyed than cortical bone. As individual
trabeculae contribute less to the overall radiographic image, relatively large
amounts of spongy bone must be destroyed before it is visible
 Analysis of the interface between tumour and host bone is a good indicator
of the rate of growth in the lesion.
 A sharply marginated lesion usually denotes slower growth than a non-
marginated lesion.
 The faster the growth, the more “aggressive” the pattern of destruction and
the wider the zone of transition between tumour and the normal bone
 Aggressivity, per se, does not conclusively indicate malignancy,but the
malignant tumours tend to be faster growing than their benign
counterparts.

48. The American skeletal radiologist, Gwilym
Lodwick, described three patterns of bone
destruction associated with tumours and
tumour-like lesions of bone:
 type 1, geographic bone destruction
 type 2, moth-eaten bone destruction
 type 3, permeative bone destruction

51. Type 1: Geographic
 In this pattern the growth rate is sufficiently
indolent and the lesion will appear well
marginated with a thin zone of transition.
 The geographic pattern may be further subdivided
into 3 types depending on the appearance of the
margin and the effect on the cortex
 Type 1A
 Type 1B
 Type 1c

52. Type 1A
 The slowest growing of all the lesions and thereby the
least aggressive, is characterized by a sclerotic margin.
 The thicker the sclerotic rim, the longer the host bone
has had time to respond to the lesions indicating a
slow rate of growth
 The vast majority of these lesions will prove to be
benign

54. Type 1B
 The lesion is well defined without the sclerotic margin.
While still relatively slow growing, the rate is slightly
greater than that of type 1A. Again, the majority of
type-1B lesions are benign, although some
malignancies may on occasion demonstrate this
pattern.

55. Type 1C
 Margin is less well defined, indicating a more
aggressive pattern.
 cortex is also destroyed.
 Few benign tumours exhibit a type-1C pattern.
 The differential diagnosis in this situation includes
giant cell tumour, malignant fibrous histiocytoma and
lymphoma of bone

57. Type 2 : Moth-eaten; Type 3 :
Permeative
 Moth-eaten and permeative patterns of bone
destruction reflect the increasingly aggressive nature
of these tumours compared with geographic lesions
 This is a spectrum of change varying from multiple
foci of bone destruction which may coalesce (moth-
eaten) to multiple tiny defects, best seen in the cortical
bone, which gradually diminish in size and frequency
from the centre to periphery of the lesion (permeative)
resulting in an ill-defined wide zone of transition

58. Ewing’s sarcoma
in the humerus.
AP radiograph
and magnified
detail show a
highly
aggressive
permeative
pattern of bone
destruction

59. Examples
 Metastasis,
 Ewing’s sarcoma and
 osteosarcoma
 Benign tumours in general do not show this pattern of
bone destruction.
 Acute osteomyelitis may also give a motheaten pattern
of bone destruction.

60. Periosteal Reaction
 Continuous Periosteal Reaction
 Discontinuous Periosteal Reaction
 Combined Periosteal Reaction

62. Continuous Periosteal Reaction
 A continuous periosteal reaction may be observed with either:
 intact or
 a destroyed underlying cortex (“expanded”)
 Expansion represents a relatively slow process by which endosteal bone
resorption is balanced by periosteal new bone formation.
 In faster-growing lesions the endosteal resorption will exceed
periosteal ap-position and a thin outer “shell” will be produced
 Shells are typically found in benign lesions:
 simple bone cyst, aneurysmal bone cyst (ABC), chondromyxoid
fibroma, fibrous dysplasia and giant cell tumour
 Shells are also well recognised in “expansile” metastases of renal and
thyroid origin and plasmacytoma

64. Plasmacytoma in
the pelvis
AP radiograph shows a large expansile lytic lesion involving the left
acetabulum and ischium

65. continuous periosteal reaction with an intact
cortex.
 solid,
 a single lamella,
 lamellated (“onion skin”) or
 spiculated (“hair-on-end”)

67. solid
 solid type implies the slow apposition of layers of new bone to the
cortex, sometimes termed “cortical thickening” or “cortical
hyperostosis”.
 chondroma,
 central chondrosarcoma, and
 eccentrically in osteoid osteoma
 If the solid periosteal reaction is extensive with an undulating quality
the differential diagnosis includes:
 chronic osteomyelitis,
 hypertrophic osteoarthropathy
 chronic lymphoedema and varicosities.

68. Hypertrophic osteoarthropathy
PA radiograph shows florid continuous periosteal reaction along the radius
and ulna.

69. lamellated periosteal reaction
 A single lamellar periosteal reaction is formed by a
thin radiodense line separated from the cortex by a
narrow radiolucent zone
 periosteal reaction is a dynamic process and a single
lamella may fill in to produce a solid appearance or go
on to the addition of further lamellae (“onion skin”).
Ewing’s sarcoma
osteosarcoma,
Langerhans cell histiocytosis (eosinophilic
granuloma)

71. spiculated (“hair-on-end”)
periosteal reaction
 This occurs when the mineralisation is oriented
perpendicular to the cortex and denotes a more rapidly
evolving process:
 Typical of malignant tumors:
 Osteosarcoma and Ewings sarcoma
 May be seen in benign tumours including
meningioma, haemangioma of bone and non-
neoplastic conditions such as thalassemia and thyroid
acropachy.

72. Periosteal
osteosarcoma in the
tibia
AP radiograph shows a
spiculated periosteal
reaction arising from the
medial aspect of the
proximal diaphysis.
obliquity of the spicules at
the periphery of the lesion
means that the pattern
could also be described as
“sun-ray” or “sun-burst”

73. Discontinuous
Periosteal Reaction
 A discontinuous or interrupted periosteal reaction indicates that the
mineralisation has been breached in one of two ways:
 Either the process, usually a tumour, simply occupies the available
space,
 or the rate of apposition of new bone is exceeded by the rate of
resorption.
 In malignant bone tumours the site of interruption of a periosteal
reaction is usually the area of maximum extra-osseous tumour growth.
 Types:
 Codmans Angle
 Buttresses
 Truncated lamellae

74. Codman Angle
 The periosteal reaction forms an angular configuration with the
underlying cortex, resembling two sides of an angle and indicates an
aggressive pathology.
 This is formed by the elevation of periosteum by tumor, blood,edema
or pus
 Angle may or may not contain tumor

76. Buttresses
 In this type the solid reactive
bone is formed at the lateral
extra osseous margin of slow
growing bone lesions, the cortex
beneath the buttress Is
frequently intact.

77. Combined
Periosteal Reaction
 More than one pattern of periosteal reaction may be
manifest in the same case and is called a combined or
complex pattern. This reflects the varying rate of
growth at different sites in the same lesion.
 The divergent spiculated periosteal reaction, otherwise
known as “sun-burst” or “sun-ray”, is a typical example
of a complex pattern and is suggestive of osteosarcoma

78. Osteosarcoma
femur.
AP radiograph
shows all the
typical features of
the tumours
including
permeative bone de-
struction, malignant
osteoid
mineralisation and a
complex periosteal
reaction

79. Tumour Mineralisation
 Tumour new bone is the matrix of intercellular substance
produced by certain tumour cells that can calcify or ossify.
 Radiodense tumour matrix is of either osteoid (osteogenic
tumours) or chondroid (chondrogenic tumours) origin.
 Tumour osteoid is typied by
 solid (sharp-edged) or
 cloud to ivory-like
 Tumour cartilage is variously described as
stippled, .
ring and arc and
popcorn in appearance

80.  Identifying the pattern of matrix calcification will
signicantly reduce the differential diagnosis, but
matrix per se has no influence as to whether the lesion
is benign or malignant, just whether the tumour is of
osteogenic or chondrogenic origin.

82. Enchondroma: Radiographs show dense chondrogenic calcications in the form of
rings and arcs in the proximal metadiaphyseal humerus. underlying osteolysis is completely
obscured by the calcifications. There is no sclerotic rim and the cortex is intact.

83. Radiographic appearance of osteoid matrix in osteosarcoma. a Lateral radiograph of the
distal femur shows predominantly fluffy osteoid matrix (asterisk) in bone and within the
large so tissue component. b Anterioposterior radiograph shows a predominantly
cloudlike (cumulous) opacity (asterisk) in the proximal humerus and adjacent so tissue

84. summary
benign malignant
 Well defined sclerotic
borders
 Geographic pattern of bone
destruction
 Continous solid periosteal
reaction
 No soft tissue extension
 Poorly defined margins with
wide zone of transition
 Moth-eaten or permeative
pattern of bone destruction
 An interrupted periosteal
reaction of the sunburst or
onion skin type
 Adjacent soft tissue mass

85. ROLE OF CT
 CT has complementary role in the diagnosis and local staging of bone
tumors.
 Surgical planning
 Custom prosthesis production
 Biopsy
 Percutaneous treatment guidance
 Scanning the chest for detection of pulmonary metastases is primary
role for CT
 CT remains essential for patients in whom MR is contraindicated
 CT provides greater morphological detail about the bone surrounding
lesion and analysis can be applied in the same way as classic
radiographic margin analysis.

86.  CT is typically used in order to obtain radiographic
information where conventional radiograph fail due to
limited contrast resolution, complex anatomy e.g. spine,
pelvis or scapula
 Most important advantage of CT over radiography is its
superior delineation of cortical alterations, of which
cortical expansion and remodelling, endosteal scalloping
and focal penetration represent the most common form in
benign bone lesion
 CT has the ability to depict periosteal reaction that might
be invisible on radiograph .
 Subtle matrix calcifications
 Intraosseous tumors are well demonstrated

92. CT of the knee, windowed for
soft tissues and bone, demonstrates subtle
periosteal reaction
of the lateral tibia and an adjacent so tissue
mass (arrows).

93. Juxtacortical chondroma: Radiographs and
computed tomography show a saucer-
like juxtacortical lesion separated by a
thick sclerotic rim from the medullary cavity

94. Osteoma of the skull in a 40-year-old woman with 12 year history of a “hard” mass. a
Townes view of the skull shows the osteoma (arrows) as a dense osseous mass arising from
the outer table of the skull. b Axial noncontrast CT displayed on bone window shows
the lobulated mass (arrows) arising from the outer table. e mass images similar to the
adjacent cortical bone

95. Osteoblastoma of the lumbar spine. a Anteroposterior radiograph of the lumbar
spine shows a lesion in the posterior elements of L4 (white asterisk) with prominent
sclerosis (black asterisk). b Axial noncontrast CT scan shows the lesion (white asterisk)
with subtle mineralized matrix, moderate expansile remodeling and prominent sclerosis
(black asterisk)

96. Osteoblastoma of the femur. a Anteroposterior radiograph of the proximal femur
shows a geographic lytic lesion (asterisk) with solid continuous periosteal new bone
(arrow) distant from the lesion. b Axial noncontrast CT scan shows the lesion with
prominent mineralized matrix and associated sclerosis

97. Anteroposterior radiograph of the wrist shows a densely sclerotic mass with
prominent expansile remodeling (arrows). b Surface rendered 3-D
CT scan shows the expansile remodeling of the mass to better advantage.
Reformatted coronal CT displayed at bone window

98. Computed tomography in a
coronal reconstruction shows a
well-demarcated lytic lesion in
the proximal epimetaphyseal femur,
one of the less frequent
locations of chondroblastoma. ere is
an incomplete thin rim
of sclerosis and the cortex is
partially destroyed.

99. Role of MRI
 MRI is the best imaging modality in assessing:
 Intra and extra compartmental extent
 Neuro vascular and juxta articular involvement
 Skip lesions

100.  Images should be obtained with the smallest practical FOV in order to
maximize image detail, while performing the entire study in a clinically
practical time period
 T1-weighted spin-echo images are particularly important in the
evaluation of bone marrow, whereas intermediate-weighted images
should be avoided.
 Fat suppression must be applied when obtaining T2-weighted fast spin-
echo images to demarcate tumor from surrounding bone marrow and
edema.
 Administration of a gadolinium-chelate contrast material can provide
useful information in characterization of bone lesions, as well as in
assessment of response to therapy and detection of recurrent tumor.

101. Imaging protocol
 T1-weighted SE
 T2-weighted Fast SE
 Gadolinium-enhanced SE
 Gradient Echo
 STIR Short-tau inversion recovery (STIR) frequently is used as an
alternative fat-suppression sequence to achieve homogeneous fat
suppression and T2-weighting, particularly in situations where fat
suppression with T2 weighted fast SE would be unsatisfactory

102. Advanced MR Techniques
 Quantitative Dynamic MR Imaging
 Diffusion-weighted Imaging
 MR Spectroscopy

103. Primary lymphoma of humerus. a Coronal T1-weighted SE image shows that signal
intensity of tumor (T) in medullary cavity is low, similar to that of muscle (asterisk). b
Coronal short-tau inversion recovery (STIR) image demonstrates diffusely high signal
intensity both within the tumor (T) and throughout extensive surrounding edema (arrows).
Note that margins of tumor cannot be visualized in b

104. Importance of fat suppression for lesion evaluation at T2-weighted fast SE imaging. a In
coronal T2-weighted fast SE without fat suppression, the lesion (arrows) in distal tibia has
high signal intensity similar to that of normal marrow (asterisk), and its border is poorly
dened. b T2-weighted fast SE image with fat suppression clearly demonstrates margins
of the lesion (arrows), and also clearly demonstrates very high signal within multiple
lobules,consistent with a chondroid lesion

105. Lesion conspicuity in gadolinium-enhanced images with and without fat suppression.
a Gadolinium-enhanced transverse T1-weighted SE image obtained without fat
suppression shows subtle mild peripheral contrast enhancement (arrows) of the lesion
in proximal femur. Peripheral high signal (arrowheads) due to chemical shi artifact partly
obscures the border of the lesion. b Sub-sequent image obtained with same parameters
and fat suppression reveals more peripheral (arrows) and nodular (arrowhead) regions of
enhancement. e previous chemical shift artifact is no longer present. Biopsy revealed
liposclerosing myxobrous tumor

106. Calcication demonstrated on T2*-weighted GE image. a Transverse T2*-weighted GE
image(TE=24 ms) shows several small signal voids (arrowheads) within a low-grade
chondrosarcoma in distal femur.
b Anteroposterior radiograph of the knee demonstrates faint foci of calcication
(arrowheads) in distal femur, corresponding to the signal voids seen in GE image

107. Nonspecic signal intensity of tumor on STIR sequence. On a coronal T2-weighted SE
image without fat suppression, diffusely low signal intensity throughout the giant cell
tumor (T) suggests chronic internal hemorrhage. On b coronal STIR image, tumor (T) is
diffusely very high in signal intensity, which improves conspicuity of the tumor but
diminishes the ability to characterize it

108. Skip lesions of
osteogenic sarcoma
in le femur.
Coronal T1-weighted SE
image reveals skip
(metastatic) lesions in
the proximal diaphysis
and distal epiphysis of
femur (arrows),
in addition to the
primary tumor (T) in
distal metaphysis

109. Diffusion-weighted imaging (DWI) in Ewing
sarcoma of tibia. a Transverse T2-weighted SE image with fat
suppression shows extensive high signal in the tumor (T) and
its subperiosteal component (arrows), as well as in surrounding
so tissue edema (arrowheads). b Transverse DWI (b=1000)
allows differentiation of tumor (T) from surrounding edema by
demonstrating increased signal in the tumor (arrows) but not
in surrounding edema

110. Fluid-like intensity within enchondroma.
Transverse T2-weighted SE image with fat
suppression demonstrates
a medullary lesion in humeral head
consisting of multiple small
chondroid lobules with very high signal
intensity (arrows)

111. Fluid-fluid levels in aneurysmal bone cyst. Trans-
verse T2-weighted SE image with fat suppression
demonstrates an expansile lesion consisting solely of
multiple .fluid-fluid levels (arrows) in proximal tibia. e
rather low signal intensity of the dependent portions of the
levels is compatible with old blood products

112. Edema around bone tumors. a Coronal T2-
weighted SE image with fat suppression
demonstrates a lesion
(T) with high signal intensity in the humeral
head. Bone marrow edema (arrows)
throughout the proximal humerus is sub-
stantially larger in extent than the lesion
(chondroblastoma)itself. Moderate joint
eusion (asterisk) is present

113. Necrosis in poorly differentiated carcinoma
in humerus. Coronal post-gadolinium-
enhanced T1-weighted SE
image with fat suppression demonstrates
relatively little enhancement in tumor (T),
and poorly defined enhancement in
surrounding edematous region. Gross
pathologic examination
revealed extensive necrosis and hemorrhage

114. sagittal T1-weighted image and heterogeneous and moderately hyperintense on c
sagittal T2-weighted image with fat suppression. d Sagittal T1-weight-
ed contrast-enhanced, fat-suppressed image shows extensively
increased signal indicating a predominantly solid, not cystic, tumour

115. Coronal post-contrast T1W SE MR
image shows the intramedullary
tumour extent, which does not
reach the distal femoral articular
surface (arrows)

116. Proximal tibial osteosarcoma with joint
involvement. Coronal PDW FSE MR
image shows tumour in the
proximal tibia extending into the ACL
(arrow) and also surrounding the lateral
meniscus (arrowhead)

117. A 21-year-old male with Ewing sarcoma primary to the le iliac bone Sagittal
T1-weighted gadolinium-enhanced fat-suppressed images reveal innumerable enhancing
metastases throughout the thoracic (a)and lumbar (b) spines (arrows)

118. Chondroblastoma: Anteroposterior radiograph (a) shows a lytic lesion in the proximal
epiphyseal humerus with slight extension into the metaphysis. The pattern of destruction
is geographic. The subchondral bone lamella is destroyed. There is considerable
metaphyseal sclerosis and periosteal reaction. T1-weighted MR images without (b) and
with (c) contrast enhancement show the demarcation of the lesion and the slight
extension into the metaphysis

119. Enostosis of the L3 vertebral body. a Lateral radiograph of the spine shows a rounded
sclerotic lesion having the typical radiographic features of an enostosis (asterisk)
with a radiating, spiculated border. Sagittal T1-weighted spin-echo MR images of the
lesion (asterisk) show a signal intensity similar to that of cortical bone with radiat-
ing speculated margin. Note peripheral location of the lesion.

121. Intracortical osteoid osteoma of the humerus in a 28-year-old man. a Axial noncontrast CT
of the proximal humerus shows the lesion (arrow) centered within the cortex. b Coronal T2-
weighted SE MR image shows the lesion (arrow) within the cortex with associated marrow
edema (asterisk)

122. Role of USG
 Ultrasound can be used to assess subperiostealor
extraosseous bone tumour extension.
 Ultrasound can accurately assess the cartilage cap of an
osteochondroma
 Bone tumours are frequently amenable to sonographically
guided core needle biopsy with excellent results.
 Ultrasound can prove useful in the detection oflocal
tumour recurrence, especially in the presence of an
endoprosthetic replacement.
 Ultrasound may have a future role in the assessment of
tumour response to neoadjuvant chemotherapy.

123. Imaging Features of Bone Tumours
on Ultrasound
 The normal cortex of a long bone is seen as a thin
hyperechoic line which produces posterior acoustic
shadowing
 Ultrasound should be used to assess the integrity of
the cortex, with the bone being scanned in the
longitudinal and transverse planes.
 Colour Doppler should also be routinely used to assess
areas of tumour neovascularity and to identify tumour
relationship to any adjacent neurovascular structures

124. a Longitudinal and b transverse images of
the mid-humerus show the hyperechoic
thin line of the bone cortex (arrows) and the
deep fascia (arrowheads), between which
lies the muscle compartment.

125. Transverse Doppler US through the forearm
in a patient with Ewing sarcoma of the proxiaml radius
demonstrates the eroded radial cortex (short arrow), the
extraosseous tumour mass (arrowheads) and the adja-
cent brachial vessels (double-headed arrow)

126. Morphological Features of Bone
Tumours on Ultrasound
 Cortex
 Ultrasound can demonstrate an intact underlying cortex where a
lesion is arising in a juxtacortical location and is not involving
the bone itself
 Pathological fractures are seen as a discontinuity and step of the
normal hyperechoic linear cortical line, which can also be
associated with an extraosseous extension of the tumour mass.
 Cortical destruction from primary intramedullary tumours,
particularly osteosarcoma and Ewing sarcoma, appears as a
discontinuity or marked irregularity of the smooth hyperechoic
line of the normal cortex, with the associated extraosseous
tumour mass

127. Longitudinal US of the humerus in a woman
with a periosteal chondroma shows the tumour mass (ar-
rowheads) and the intact underlying cortex (arrows)

128. Longitudinal US of the femur in a child with osteosar-
coma shows irregular discontinuity of the femoral cortex (arrows)
with an associated extraosseous mass (arrowheads)

129. Periosteum
 Ultrasound can demonstrate the unmineralised
periosteum as a thin, hyperechoic line overlying the
extraosseous tumour mass
 A multilaminated periosteal reaction may be seen as
multiple thin hyperechoic lines
 A Codman’s triangle seen on plain radiographs
manifests as a smooth angulation of the cortex at the
tumour margin

130. Periosteal response. a Longitudinal US through the upper forearm in a
child with a proximal radial Ewing sarcoma shows the tumour mass
extending through the permeated cortex (arrows) and covered by the intact
periosteum (arrowheads). b Longitudinal US in a child with a
distal femoral osteosarcoma shows a Codman’s triangle (arrows) at the site
of extraosseous tumour extension (arrowhead)

131. Neurovascular Bundle
 Ultrasound can demonstrate displacement or
encasement of the neurovascular bundle
 useful in assessing flow within the vessels and
ensuring that biopsy approaches are remote from the
neurovascular bundle, which can sometimes be
difficult to appreciate with CT-guided biopsy.

132. Longitudinal US through the arm in a patient
with lymphoma of the humerus shows a large soft tis-
sue mass extending from the bone surface (arrows) and
displacing and partially encasing the brachial artery
(arrowheads)

133. Osteosarcoma. a Transverse US through the femur
(arrow) shows an extraosseous
mass (arrowheads) containing heterogeneous hyerechoic
areas due to matrix ossifcation. b Axial
fat-suppressed, proton-density-weighted, fast spin-echo
(PDW FSE) MR image

134. Transverse US show multiple fluid levels
(arrowheads). d Longitudinal colour
Doppler US shows marked neovascu-
larity within th extraosseous mass (arrows)

135. Longitudinal US of the rib shows a sessile osteochondroma (arrows)
with a small overlying hypoechoic cap (arrowhead). Peripheral chondrosarcoma. b
Anteroposterior radio- graph of the ankle shows a sessile osteochondroma (arrows) of
the fibula. c Longitudinal US shows a very thick, heterogeneous mass (arrows) arising
from the surface of the osteochondroma (arrowheads)