A comprehensive imaging approach to various Primary malignant tumors.

1. An Approach to Malignant
Bone Tumors
Dr.Suhas B
MD Radio-Diagnosis

2. Introduction
• Bone tumors are classified into:
– Primary bone tumors
– Secondary bone tumors ( Metastasis)
• Most are classified according to the no rm alce llo f o rig inno rm alce llo f o rig in and apparent
pattern of differentiation.
• Forms 0.2% of human tumor burden.
• Primary malignant bone tumors make 1% of all malignant tumors.
• Commonest bone tumour is secondaries from other sites.
• Commonest primary bone tumour is multiple myeloma, second
osteosarcoma.

3. Occurence

4. Classification
• Bone-forming tumours
• Cartilage forming tumours
• Giant-cell tumour
• Marrow tumours
• Vascular tumours
• Other connective tissue tumours
• Other tumours
• Secondary malignant tumours of bone

5. Bone-forming tumors
(malignant)
 Osteosarcoma
• Central (medullary)
• Peripheral (surface)
 Paraosteal
 Periosteal
 High grade surface
Cartilage-forming tumors
(malignant)
 Chondrosarcoma
• Differentiated chondrosarcoma
• Juxta-cortical chondrosarcoma
• Mesenchymal chondrosarcoma
• Clear cell chondrosarcoma
Marrow tumors (malignant)
 Ewing’s sarcoma
 Neuroectodermal tumour
 Malignant lymphoma of bone
(Primary/secondary)
 Myeloma
Vascular tumors (malignant)
 Angiosarcoma
 Malignant haemangio
pericytoma
Other tumors (malignant)
 Chordoma
 Adamantinoma

6. Other connective tissue
tumours (malignant)
 Fibrosarcoma
 Malignant fibrous
histiocytoma
 Liposarcoma
 Malignant mesenchymoma
 Leiomyosarcoma
 Undifferentiated sarcoma
Secondary malignant
tumours of bone
 Osteoblastic
 Osteolytic
 Mixed Lesions

7. Evaluation
• Age & Sex
• Symptomatology
– Pain
– Swelling
– History of trauma
– Neurological symptoms
– Restriction of movement
– Other constitutional sympotms (cough, chest pain, backache, loss of
appetite etc)
• Pathological fracture
• Associated conditions
• Prior surgeries/investigations

8. Age distribution of various bone tumors

9. Imaging
• Plain radiography
• CT scan
• MRI
• Radionuclide scanning
• PET

10. Plain Radiography
Information yielded by radiography includes :
• Size
• Site of the Lesion
• Borders of the lesion/zone of transition
• Type of bone destruction
• Periosteal reaction
• Matrix of the lesion
• Nature and extent of soft tissue involvement
• Multiplicity

11. Plain radiography (contd.)
Size
• It helps us in pre treatment staging of the tumor.
• The larger the lesion the more likely to be
aggressive or malignant.

12. Plain radiography (contd.)
Site
• Type of bone
• Long bone / Flat bone
• Intramedullary /
Eccentric / Cortical
lesion
• The epicenter of the
tumor helps to
determine the origin.
• Epiphysis /
Metaphysis /
Diaphysis

13. Distribution of various bone tumors

14. Distribution of various lesions in a long
tubular bone before skeletal maturity
Distribution of various lesions in a long
tubular bone after skeletal maturity

15. Distribution of various lesions in a vertebra
Benign lesions
predominate in its
posteriorelements.
Osteoblastoma
Osteoid osteoma
Aneurysmal Bone
cyst
Osteochondroma
Chondromyxoid
fibroma
Malignant lesions are
seen predominantly in
its anteriorpart (body)
Lympohoma
Myeloma
Osteosarcoma
Ewing
Chondrosarcoma
Metastases

17. Zone of Transition
• The zone of transition is the most reliable indicator in determining whether
an osteolytic lesion is benign or malignant.
• The zone of transition only applies to osteolytic lesions since sclerotic
lesions usually have a narrow transition zone.
• A small zone of transition results in a sharp, well-defined border and is a
sign of slow growth. A sclerotic border especially indicates poor biological
activity.
• An ill-defined border with a broad zone of transition is a sign of aggressive
growth.

18. Narrow zone of transition Wide zone of transition

19. Patterns of Bone Destruction
• Mechanisms of bone destruction
– Direct effect of tumor cells
– Increased osteoclastic activity
• Cortical bone is destroyed less rapidly than trabecular bone.
– Loss of cortical bone appears earlier on radiography
– trabecular bone must be destroyed (about 70% loss of mineral
content) before the loss becomes radiographically evident
• Bone destruction can be described as
– geographic (type I) - benign lesions
– moth-eaten (type II) and
– permeative (type III) - rapidly growing infiltrating tumors

20. Patterns of Destruction
Less malignant More malignant
Geographic Moth-eaten Permeative

21. Types of Periosteal reaction
• Benign
– None
– Solid/Continuous
• More aggressive or
malignant
 Interrupted
– Lamellated or onion-
skinning
– Sunburst
– Codman’s triangle

22. Periosteal Reactions
Less malignant More malignant
Solid
Sunburst
Codman's
Triangle
Lamellated

23. C. by the presence of a
solid sclerotic mass, such
as in parosteal
osteosarcoma
Types of matrix: osteoblastic
A. fluffy, cotton-like
densities within the
medullary cavity, e.g in this
case of osteosarcoma of the
distal femur
B. presence of the wisps of
tumor-bone formation, like in
this case of osteosarcoma of
the sacrum
The matrix of a typical osteoblastic lesion is characterized by the presence of
the following features :

24. Types of matrix: chondroid matrix
A: Schematic representation of various
appearances of chondroid matrix calcifications.
B: Enchondroma
displays a typical
chondroid matrix
C: Chondrosarcoma
with characteristic
chondroid matrix

25. Radiographic features differentiating primary soft tissue tumor invading bone
from primary bone tumor invading soft tissues

26. Radiographic features that may help differentiate benign from
malignant lesions

27. CT
• Features are similar to that of plain radiograph, however CT scanning may be
helpful locally when the radiographic appearances are confusing, particularly in
areas of complex anatomy.
• Very useful in early diagnosis.
• Cross-sectional images provide a clearer indication of bone destruction, as well
as the extent of any soft tissue mass, than the radiographs.
• CT scanning may depict small amounts of mineralized osseous matrix not seen
on radiographs.
• The modality may be particularly helpful in visualizing flat bones, in which
periosteal changes may be more difficult to appreciate.
• Early detection of pulmonary secondaries
• Exact measurement for limb salvage procedures (Prosthesis/allograft)
• Used for prognostic follow-up of the patient.

28. MRI
• Investigation of choice to assess intra-medullary extension and soft
tissue involvement.
• Defines the relationship to the nearby neurovascular bundles.
• Ambiguous and inconspicuous cases.
• Helps in staging of the tumor and to plan its surgical management.
Radio-nuclide bone scan
• For pre biopsy staging
• Dissemination of tumour
• Silent secondaries and skip lesions
Arteriogram
• Planning limb sparing surgery
• Therapeutic embolization
• To assess vascularity of tumour

29. Osteosarcoma
• Osteosarcoma is a primary bone-producing
malignant mesenchymal tumor.
• It is the most common primary malignant tumor of
bone, excluding plasma cell myeloma.
• Osteosarcoma represents 20% of all primary
malignant bone tumors.
• Osteosarcoma is encountered most commonly in
the age group from 10 to 25 years (75% of cases);
few cases occur before age 5 or after age 30.
• M:F=2:1
• The metaphyseal lesion abutting the physis is the
classic location in 75% of cases.
• Although usually in the long bones, may occur in
other places:
 Craniofacial
 Small bones
 Extraskeletal (soft tissue)
Associations - Irradiation, Pagets disease, Rothmund-
Thompson syndrome

30. Osteosarcoma (contd.)
Radiography
Conventional Radiography
• medullary and cortical bone
destruction
• wide zone of transition,
permeative or moth-eaten
appearance
• aggressive periosteal
reaction
• sunburst type
• Codman triangle
• lamellated (onion skin)
reaction: less frequently
seen
• soft-tissue mass
• tumour matrix
ossification/calcification
• variable: reflects a
combination of the amount
of tumour bone production,
calcified matrix, and osteoid
• ill-defined "fluffy" or "cloud-
like" cf. to the rings and arcs

31. Osteosarcoma (contd.)
CT
• Cross-sectional images provide a clearer
indication of bone destruction, as well as the
extent of any soft tissue mass, than do
radiographs.
• CT scanning may depict small amounts of
mineralized osseous matrix not seen on
radiographs. The modality may be particularly
helpful in visualizing flat bones, in which
periosteal changes may be more difficult to

32. Osteosarcoma (contd.)
MRI
T1WI - Low/heterogenous signal intensity
T2WI - High signal intensity
Constrast - enhancing medullary cavity and solid
components.
STIR - High signal intensity and helps in
assessing involvement of neurovascular
bundles and muscles.

33. Multiple Myeloma
• Multiple myeloma is the most
common primary malignant neoplasm
of the skeletal system. The disease is
a malignancy of plasma cells.
• Average age is 60-70
• Much more common in men than
women
• Most have an elevated serum protein
with 80-90% in the globulin fraction,
especially IgG
• Bence-Jones protein in 40-60% of
patients
• Most commonly affected bones are:
vertebrae (66%), ribs (45%), skull
(40)%, shoulder (40%), pelvis (30%),

34. Multiple Myeloma (contd.)
Plain Radiography
• A full skeletal survey is required for proper
evaluation.
• No. of lytic lesions is directly proportional
to the tumor load.
• Classical lesions are well defined
rounded/punched out lytic lesions
scattered diffusely among the involved
bones.
• Such lesions in skull gives 'pepper pot' or
'swiss cheese' appearance, however the
occipital bone is spared.
• Multiple deformed vertebral bodies.
• Diffuse osteopenia
• No periosteal bone formation.
• Medullary involvement in the form of
endosteal scalloping.

35. Multiple Myeloma (contd.)
CT
• Computed tomography (CT) scanning readily
depicts osseous involvement in myeloma.
• CT allowed a more accurate evaluation of areas at
risk of fracture.
• Tool of choice utilised in image guided spinal or
pelvic bone biopsy.
MRI
• Most sensitive imaging modality at detecting
diffuse and focal multiple myeloma in the spine, as
well as the extra-axial skeleton
• Mainly bone marrow based lesions.
• T1WI - Low signal intensity
• T2WI and STIR - High signal intensity.
• Show enhancement on contrast enhanced
images.

36. Chondrosarcoma
• malignant cartilaginous tumour and
second most frequent primary
malignant tumor of bone, representing
approximately 25% of all primary
osseous neoplasms.
• Typical presentation is in the 4th and
5th decades and there is a slight male
predominance
• Further differentiated into Primary and
secondary
• Most common bones involved are
long bones (45%), pelvis (25%), ribs
(8%), spine (7%), scapula (5%),
sternum (2%)
• Patients with multiple enchondromas
like in Ollier's disease and Mafucci's

37. Chondrosarcoma (contd.)
Plain radiography
• large mass at the time of diagnosis,
usually over 4 cm in diameter in 50% of
cases.
• lytic (50%)
• intralesional calcification(s): 60-78% (rings
and arcs calcification or popcorn
calcification)
• endosteal scalloping
• affects more than two thirds of the cortical
thickness (c.f. less than 2/3 in
enchondromas)
• moth eaten appearance or permeative
appearance in higher grade tumours
• cortical remodelling, thickening and
periosteal reaction are also useful in

38. Chondrosarcoma (contd.)
CT
• In as many as 90% of cases, tumors
appear as lucent areas containing
chondroid matrix calcification. Endosteal
scalloping and cortical destruction are
frequently easier to appreciate on CT
scans than on radiographs.
• CT scanning may be used to guide
percutaneous biopsy
MRI
• T1: low to intermediate signal
• T2: very high intensity in non
mineralised/calcified portions
• gradient echo/SWI: blooming of
mineralised/calcified portions
T1 C+ (Gd)
• most demonstrate heterogeneous
moderate to intense contrast
enhancement.
• enhancement can be septal and peripheral
rim-like corresponding to fibrovascular

39. Ewings Sarcoma
• Ewing sarcoma, a highly malignant
primary bone tumor that is derived
from red bone marrow and second
most common primary bone tumour of
childhood.
• This tumor is most frequently
observed in children and adolescents
aged 4-15 years and rarely develops
in adults older than 30 years.
• Affected bones include, long bones:
50-60%, femur: 25%, tibia: 11%,
humerus: 10%, flat bones: 40%,
pelvis: 14%, scapula, ribs: 6%
• As far as location within long bones,
the tumor is almost always
metaphyseal or diaphyseal.
• It is the most lethal bone tumor. An
association exists between Ewing

40. Ewing's Sarcoma (contd.)
Plain Radiography
• Typical presentation: ill-defined
osteolytic lesion with a moth-eaten
or permeative type of bone
destruction, irregular cortical
destruction and aggressive
periostitis.
• reactive sclerosis, irregular
periosteal reaction and soft tissue
mass.
• Ewing sarcomas tend to be large
poorly marginated tumours, with
over 80% demonstrating extension
into adjacent soft tissues.
• laminated (onion skin) periosteal
reaction: 57%

41. Ewings Sarcoma (contd.)
CT
• CT scanning helps to define the bone
destruction that is associated with
Ewing sarcoma.
• Tumor size can be evaluated with
contrast-enhanced CT scanning,
which may be used in follow-up
evaluation during chemotherapy.
MRI
• MRI is essential to elucidate soft-
tissue involvement
• T1: low to intermediate signal
• T1 C+ (Gd): heterogeneous but
prominent enhancement
• T2: heterogeneously high signal, may
see hair on end low signal striations

42. Lymphoma
• Primary lymphoma of bone (PLB) is a rare,
malignant, neoplastic disorder of the
skeleton. Also known as Reticulum cell
sarcoma.
• Primary bone lymphoma occurs in a broad
range of patients, aged 1 year 6 months to
86 years (median range, 36–52 years) (5),
with a peak prevalence among patients in
the 6th to 7th decades of life.
• Presentation: usually pain and palpable
mass.
• Preferential sites: femur, tibia, humerus
and iliac bone.
Plain Radiography
The features vary widely in appearance.
The most common ones are as below :
 Permeative, lytic pattern of bone
destruction (74%)
 Metadiaphyseal location (69%)
 Periosteal reaction (58%)

43. Lymphoma (contd.)
CT
• useful adjuncts to conventional
radiographs
• pattern appears as extensive
evidence of disease within the marrow
cavity associated with a surrounding
soft-tissue mass but without extensive
cortical destruction
• Cortical breakthrough is well
appreciated.
MRI
• T1WI - low signal intensity within the
marrow
• T2WI - High signal intensity

44. Adamantinoma
• rare primary malignant bony tumour, only
approximately 200 cases have been
reported.
• The tumor occurs almost exclusively in the
long bones; tumors in the tibia account for
more than 80% of cases. The diaphyseal
region is the area most commonly
affected. Other bones affected are the jaw,
ulna, humerus, femur, and fibula.
• Typically presents in the 2nd to 3rd
decades as a locally aggressive mass 3-15
cm in diameter.
• Differentiated <20 years of age> Classic
• 10-year survival rate is believed to be 10%
• Adamantinoma may present as a solitary
focus or multicentric lucencies or slightly
expansile osteolytic lesion
• May extend into the marrow cavity.
• Lesions tend to have an eccentric
epicenter and a lack of periosteal reaction.
• usually no periosteal reaction is noted in
the surrounding bone
• Long-standing tumors produce marked

45. Adamantinoma
MRI
• two morphologic patterns are seen :
- a solitary lobulated focus
- multiple small nodules in one or
more foci.
• In some patients separated tumour
foci may be seen, defined as foci of
high signal intensity on either T2- or
T1-weighted contrast-enhanced
images, interspersed with normal-
appearing cortical or spongious bone.
• Fluid-fluid level may occasionally be
seen.
• C+(Gd): tends to show intense and
homogeneous static enhancement,
although there is no uniform dynamic
enhancement pattern.

46. Metastases
• Metastatic bone tumors are the most common malignant tumors of the skeleton.
Approximately 70% of all malignant tumors are metastatic in origin.
• metastases are usually found in: Vertebrae - especially posterior vertebral body,
extending into pedicle, pelvis, proximal femur, proximal humerus and skull.
• Metastases distal to the elbow and knee are distinctly uncommon.
Types :
- osteolytic metastases
- sclerotic/osteoblastic metastases
- mixed lytic and sclerotic metastases
Osteoblastic metastases Osteolytic metastases Mixed
metastases
prostate carcinoma (most common) RCC Lung carcinoma
(25%)
breast carcinoma (may be mixed) Thyroid carcinoma Breast
carcimoma (15%)
transitional cell carcinoma (TCC) Pheochromocytoma carcinoma of
cervix
carcinoid Wilms tumor testicular tumors
medulloblastoma Ewings sarcoma Prostatic
carcinoma (15%)
neuroblastoma Carcinomas of GIT

47. Metastases (contd.)
Imaging Findings
• little or no soft tissue mass
associated with them
• Usually no periosteal reaction
• May appear as moth-eaten,
permeative or geographic lesions
• Indistinct zones of transition, no
sclerotic margins and may be sharply
circumscribed or have indistinct
borders
• Lesions distal to elbows and knees -
50% are from lung and breast
• Diffuse skeletal sclerosis or multiple
round, well-circumscribed sclerotic
lesions - Prostate & Breast
• Expansile and lytic (soap-bubbly) -
RCC
• Cookie-bite lesions of the cortices of
long bones - Lung
• Bone scans are extremely sensitive
but not very specific
• 10-40% of lesions will not be visible
on plain film but will be positive on
bone scans

48. Metastases (contd.)

49. Fibrosarcoma
• Fibrosarcoma is a tumor of
mesenchymal cell origin that is
composed of malignant fibroblasts in a
collagen background..
• It can occur as a soft-tissue mass or as a
primary or secondary bone tumor.
• Primary fibrosarcoma - central (arising
within the medullary canal) or peripheral
(arising from the periosteum)
• Secondary fibrosarcoma of bone arises
from a preexisting lesion or after
radiotherapy to an area of bone or soft
tissue.
• Fibrosarcomas of bone are typically seen
between the third and sixth decades of
life.

50. Fibrosarcoma (contd.)
Plain Film
Highly destructive with a wide zone of
transition and often expansile. Periosteal
reaction is uncommon. The lesion
usually has not matrix mineralization, but
may have areas of sequested bone.
Often associated with a large soft tissue
mass.
CT
CT scanning is used to delineate bone
involvement, bone destruction, or bone
reaction.
MRI
best modality overall for examining soft-
tissue masses and for detecting the
intraosseous and extraosseous extent of
many bony sarcomas.
T1WI - Isointense
T2WI - Hyperintense

51. Pleomorphic undifferentiated sarcoma
• Previously known as malignant fibrous
histiocytoma.
• high grade tumor composed of
fibroblasts, myofibroblasts, and
histiocytes.
• most frequent soft tissue tumor in
adults.
• found in the extremities 70-75% of the
time and 50% of all cases are in the
lower extremity.
• highest incidence is during the fifth
decade of life and there is a male to
female ratio of 1.5 to 1
Plain Film
Plain x-rays will demonstrate a soft
tissue mass and if arising from bone,
then an aggressive destructive bony
lesion. In some cases, curvilinear or
punctate regions of calcification may be

52. Pleomorphic undifferentiated sarcoma
CT
• The density of MFH is typically similar
to adjacent muscle, with heterogeneous
lower density areas if haemorrhage,
necrosis or myxoid material is
abundant.
• The soft tissue component enhances.
• In up to 15-20% of cases some
mineralisation is present.
MRI
typically relatively well circumscribed,
located within or adjacent to muscle,
exerting positive mass effect on
surrounding structures.
T1WI - Highly variable, isointense (muscle),
T2WI - intermediate to high signal intensity
Heterogeneous and shows enhancement
of solid components.

53. Chordoma
• Chordomas are uncommon malignant
tumours that account for 1% of
intracranial tumours and 4% of all
primary bone tumours.
• They originate from embryonic remnants
of the primitive notochord.
• Occurs between the ages of 30-70 with a
2:1 male:female ratio
• 50% occur in sacrum, in 4th
or 5th
sacral
segment.
• 35% at skull base around clivus
• vertebral body: 15-30%
Plain Film
• Large presacral mass (>10cm),
destruction of multiple sacral and
coccygeal segments.
• Sclerotic rim in 50%, amorphous
calcifications ( mainly peripherally)
• May cross the sacroiliac joint

54. Chordoma (contd.)
CT
• CT is helpful in defining bone destruction
and calcification within lesion.
• With contrast, the pseudocapsule may
enhance.
• Usually low attenuation soft tissue mass with
destruction of the sacrum and/or coccyx,
sometimes with marginal sclerosis.
• May show sequestered bone fragments or
calcifications within tumor.
MRI
T1WI – intermediate to low signal intensity with
a small foci of hyperintensity (hemorrhage or
mucus)
T2WI - most exhibit very high signal .
T1 C+ (Gd): heterogeneous enhancement with
a honeycomb appearance corresponding to
low T1 signal areas within the tumour

55. Bibliography
 Essentials of skeletal radiology 3rd
edition - Yochum & Rowe
 CT and MRI of whole body 5th
edition – John.R.Haaga
 Musculoskeletal Imaging – The Requisites 3rd
edition – B.J.Manaster
 Musculoskeletal MRI 2nd
edition – Helms
 Bone Tumors and Tumor like Conditions: Analysis with Conventional
Radiography – Miller
 Expert DDX Musculoskeletal system – B.J. Manaster
 Pathologic and Radiologic features of primary Bone tumors - Update.com
 Imaging in various primary and secondary bone tumors - Medscape
 Bone tumors - Radiology assistant ; Radiopedia
 Study in various primary bone tumor - Journal of Bone Oncology;
PubMed;RSNA;KJR;IJR
 Metastatic diseases of bone – Learning Radiology