Bone tumors overview

1. JULY 2007 TUMOURS 1
BONE TUMOURS &
TUMOUR-LIKE CONDITIONS
Dr. Munshya
17/06/2021

2. TUMOURS 2
Learning Outcomes
By the end of this lecture you should be able to:
1. Classify bone tumours
2. Describe clinical, radiological and histological
features of benign & malignant tumours &
tumour-like conditions
3. Enumerate the common tumours in Zambia
4. Outline the principles of management of most
common tumours

3. TUMOURS 3
Introduction
 Primary bone tumours are
generally rare
 Most common bone tumour is a
secondary (metastatic) deposit
 The most common malignant
primary bone tumour in Zambia is
Osteosarcoma

4. TUMOURS 4
Nomenclature
Primary bone tumours are of
three varieties:
1. Benign
2. Malignant
3. Lesions that simulate bone
tumours

5. TUMOURS 5
Classification
Histology Type Benign Malignant
Haematopoietic Myeloma
• Lymphoma
Chondrogenic Osteochondroma Chondrosarcoma
Chondroma Chondroblastoma
Chondromyxoid Fibroma
Osteogenic Osteiod Osteoma Osteosarcoma
Osteoblastoma
Fibrogenic Fibroma Fibrosarcoma
Malignant fibrous Histiocytom
Lipogenic Lipoma Liposarcoma
Neurogenic Neurilemoma
Notochordal Chordoma
Vascular Haemangioma Haemangioendothelioma
Unknown Origin Giant Cell Tumour (GCT) Ewings Tumour (Sarcoma)
Histiocytoma Malignant
Adamantinoma

6. TUMOURS 6
Tumour-like Conditions
(simulators)
Young Patient Adult Elderly Patient
Eosinophilic Granuloma
Osteomyelitis
Avulsion Fractures
Aneurysmal Bone Cyst (ABC)
Fibrous Dysplasia
Osteofibrous Dysplasia
Heterotopic osssification
Unicameral Bone Cyst (UBC)
Giant cell reparative
granuloma
Exuberant callus
Synovial Chondromatosis
Pigmented villonodular
synovitis (PVNS)
Stress fracture
Heterotopic Ossification
Ganglion cyst
Metastatic bone disease
Mastocytosis
Hyperparathyroidism
Paget’s disease
Bone infarcts
Ganglion cyst
Cyst secondary to joint
disease
Epidermoid cyst

7. TUMOURS 7
PRINCIPLES
HISTORY & EXAMINATION
STAGING
WORKUP
RADIOLOGY
BIOPSY
PROCEDURES
CHEMOTHERAPY
RADIOTHERAPY

8. TUMOURS 8
HISTORY
 Presenting complaint
 Pain and / or swelling
 Character / duration of
symptoms
(distinguish benign / malignant
clinically)
 Past and family history
 Loss of weight
 Other

9. TUMOURS 9
AGE
 Probability of OS in 12-25 yrs
 Mets in > 50 yrs
 Chondroblastoma vs GCT
10-20 yrs vs 17-30 yrs
vs

10. TUMOURS 10
CLINICAL
EXAMINATION
 General health
 Anemia , wasting , spleen ?
 Skin lesions
 Precocious puberty
 Exophthalmos ( EG , FD )

11. TUMOURS 11
CLINICAL
EXAMINATION
(age,sex,site,past history)
 Breasts
 Thyroid
 Chest
 Liver
 Kidney
 Rectal

12. TUMOURS 12
LOCAL
EXAMINATION
 Location ( epi , meta , diaphysis )
( solitary or multiple )
 Tumor size
 Consistency ( bone or soft tissue )
 Fixed or mobile
 Solitary or multiple
 N/V status
 Lymph nodes ?

13. TUMOURS 13
TUMOUR WORKUP
 Bloods
 Urinalysis
 CXR
 Plain X-rays
 Bonescan
 MRI
 CT (lesion/chest)
 Angiography
 Biopsy

14. TUMOURS 14
STAGING
(ENNEKING)
ENNEKING'S SURGICAL STAGES
STAGE GRADE SITE METASTASES
1A
1B
Low(G1)
Low(G1)
Intracompartmental(T1)
Extracompartmental(T2)
None(M0)
None(M0)
2A
2B
High(G2)
High(G2)
Intracompartmental(T1)
Extracompartmental(T2)
None(M0)
None(M0)
3 Low(G1) or High(G2)
Intracompartmental(T1)
or
Extracompartmental(T2)
Yes(M1)

15. TUMOURS 15
GRADING
 G0= Histologically benign ( well differentiated and
low cell to matrix ratio )
 G1= Low grade malignant (few mitoses, moderate
differentiation and local spread only )
 G2= High grade malignant (frequent mitoses, poorly
differentiated, high risk for metastases )

16. TUMOURS 16
Features of
aggressive tumours
 Cellular atypia
 Frequent mitoses
 Extensive necrosis
 Significant vascularity
 Small amounts of immature
matrix

17. TUMOURS 17
Enneking’s 5 Questions
1. Age?
2. Site?
3. What is the tumour doing to the bone?
4. What is the bone doing to the tumour?
5. Any complications?

18. TUMOURS 18
Osteoid Osteoma
Incidence
• Accounts for 10% of benign bone tumours
• Male : Female 2:1
• Peak age 5 - 25 years (85% in this range)
• Rare over 40 years
Location:
 Any bone, rarely multifocal
tibia & femur in 50%
spine - posterior elements
Only occurs in bones formed by endochondral ossification
May affect any part of a bone but is usually intracortical

19. TUMOURS 19
Osteoid Osteoma
Clinical Presentation
 Pain is the commonest presentation
 Pain often worse at night and relieved by aspirin (more likely
NSAIDs)
 10% occur in the spine and may -> scoliosis
 Other sites may -> joint effusion, synovitis
 Runs a self limiting course but usually -> surgery for pain relief
 Pain usually decreases as the lesion matures lasting 18 - 30 months

20. TUMOURS 20
Osteoid Osteoma
X-Rays
 Lytic nidus
surrounded by
sclerotic bone
(which may mask the
nidus)
 Centre of nidus may
be calcified
 CT or tomograms ->
diagnosis
 Hot spot on bone
scan

21. TUMOURS 21
Osteoid Osteoma
Differential Diagnosis
• Brodie's abscess
• Osteoblastoma
• Stress fracture
Treatment
 NSAIDs
 relieves symptoms
 may take 3-4 years for symptoms to resolve
 Surgical:
 Nidus excision -> no recurrence (need only intact rim of reactive bone around
the nidus to ensure complete excision)
 Intraoperative localisation with:
• Bone scan
• Tetracycline (4mg tetracycline per kg qid 1-2 days pre operatively -> specimen excised
under UV light)
• CT
• X-Ray excised tissue -> contains nidus

22. TUMOURS 22
Osteochondroma
(Exostosis)
 Cartilage capped bony projection /
exostosis
 Commonest benign tumour of bone
 Developmental abnormality of the
metaphyseal area of any bone formed
in cartilage (endochondral ossification)
 Probably arise from aberrant cartilage
from the perichondral ring of the
growth plate

23. TUMOURS 23
Osteochondroma
(Exostosis)
Incidence
 Accounts for 45% of benign bone tumours
 12% of all bone tumours
 most become evident under 20 years
 May be solitary or multiple (diaphyseal aclasis)
 Any bone developing by endochondral
ossification may be involved

24. TUMOURS 24
Osteochondroma
(Exostosis)
 Present with lump or interference of
tendon function
 50% are distal femur, upper tibia or
proximal humerus
 May be sessile or pedunculated
 Active growth during skeletal growth -
>become latent
 Move towards the diaphysis with
growth and usually angle away from the
growth plate
 During growth period bone scan -
>activity at the tip
 Increased activity on bone scan
after maturity suggests malignant
change

25. TUMOURS 25
Osteochondroma
(Exostosis)
Radiology
 x-ray hallmark is blending of
tumour into underlying metaphysis
 flat, sessile lesion or a peduculated
(stalk like) process
 pedunculated osteochondromas
tend to point away from the physis
 look for a well defined metaphyseal
excrescence of bone with a mottled
density
 Cartilaginous cap displays irregular
areas of calcification

26. TUMOURS 26
Osteochondroma
(Exostosis)
Pathology
 Normal bone covered by a
cap of normal cartilage
 Cartilage cap resembles
layers of the normal
growth plate
 The cartilage is more
disorganized than normal
 Binucleate chondrocytes in
lacunae
 Covered with a thin layer
of periosteum

27. TUMOURS 27
Osteochondroma
(Exostosis)
Treatment
 Nil required unless symptomatic (persistent
irritation (from bursitis or tendon) or neurovascular
compromise)
 Extra capsular marginal excision
 Including the cartilaginous cap & overlying
perichondrium
 Deep bony base has minimal activity & may be
removed piecemeal
 Recurrence = < 5%
 Decreased risk of recurrence if excised after
maturity

28. TUMOURS 28
Giant Cell Tumour
(GCT)
 Benign, usually solitary and locally aggressive
 10% of benign bone lesions
 Can undergo malignant transformation (5-10%)
 Not seen until after the growth plate closes
 Rarely metastasises (<1% to lungs)
 Age 20 - 40 years
 More common in females
 Most commonly seen in the distal femur, proximal tibia and the distal radius
 Nearly always located at the very end of a long bone (Subchondral)
 Pathological fracture occurs in 10 - 15%
 Neighbouring joint often irritated (effusion)

29. TUMOURS 29
Giant Cell Tumour
(GCT)
Presentation
 Pain, swelling
 Pathological
fracture

30. TUMOURS 30
Giant Cell Tumour
(GCT)
X-Rays
 Usually well defined
lesion in the epiphysis
extending up to the
joint surface
(subchondral) without
marginal sclerosis,
cortex thinned and
sometimes ballooned
 soap bubble appearance
 Junction with normal
bone poorly defined

31. TUMOURS 31
Giant Cell Tumour
(GCT)
Pathology
 Soft, friable tumour
 Cut surface tan in colour, with
areas of necrosis and
haemorrhage
 Numerous multinucleated giant
cells. The stromal cells are
homogenous mononuclear
round/ovoid with large nuclei
 The nuclei of the stromal cells
are identical to the nuclei of the
giant cells, a feature which
distinguishes giant cell tumour
from other conditions containing
giant cells
 Up to 50% have soft tissue
extension but does not indicate
malignancy

32. TUMOURS 32
Giant Cell Tumour
(GCT)
Treatment
 Intralesional excision by "extended" curettage
 Curettage alone has a high local recurrence rate (50%) and the
curettage is "extended" into the bone by a few millimetres by
either using a burr, liquid nitrogen or phenol
 The resulting cavity can be filled with bone graft or cement
 En-bloc resection is possible if the bone is expendable e.g. proximal
fibula, proximal radius
 Amputation reserved for massive local recurrence, malignant change
or infection
 Radiotherapy reserved rare cases of unresectable tumours because
of increased risk of secondary malignancy

33. TUMOURS 33
Osteosarcoma
 Primary malignant tumour arising from bone and producing bone
Incidence
 Male : Female 2:1
 Bimodal age distribution: -
 Peak 1: 10 - 20 years (age of rapid growth)
 Peak 2 : 50 - 70 years (80% less than 30 and those more than 40 years usually
secondary to Pagets)
 Most common primary bone tumour in adolescents,
 75% occur in the distal femur or around the knee
 25% occur in the humerus
 90% are metaphyseal in long bones
 10% present with macroscopic metastatic disease

34. TUMOURS 34
Osteosarcoma
Types
 Intramedullary (classical or ordinary)
osteosarcoma
 Surface osteosarcomas:
 Parosteal osteosarcoma
 Periosteal osteosarcoma
 Secondary osteosarcomas:
 Paget’s
 Postradiation

 Telangiectatic osteosarcoma

35. TUMOURS 35
Osteosarcoma

36. TUMOURS 36
Osteosarcoma
Clinical Presentation
 Pain which is constant and worse at
night
 Pathological fracture is rare
 May have a tender lump which may lack
a definite edge and may be attached
to muscle
 If vascular may pulsate and feel warm

37. TUMOURS 37
Osteosarcoma
X-Rays
 Variable with combination of
bone destruction and bone
formation
 Sun ray spicules (Radial
ossification) and
 Codmans triangle (lifting of
periosteum) may be evident
 Cortical breach common
 Adjacent soft tissue mass
 Joint space rarely involved
 25% Lytic
 35% Sclerotic
 40% Mixed

38. TUMOURS 38
Osteosarcoma
Pathology
 Pleomorphic and
anaplastic cell population
with abundant fibrous
and chondroid matrix
 Stroma of spindle cells
with numerous mitoses.
 Most are high grade
aggressive tumours
usually about 10cm
diameter at diagnosis (~
10/12 growth)
 50% -> osteoblastic
 25% -> chondroid
 25% -> fibroblastic

39. TUMOURS 39
Osteosarcoma
Differential Diagnosis
 Post traumatic callus or myositis
ossificans
 Stress fracture - pathology may look
similar
 Osteomyelitis
 Ewings

40. TUMOURS 40
Osteosarcoma
Consider osteosarcoma as a systemic disease therefore
remove the primary site by en bloc excision and treat
microscopic disease by chemotherapy
Chemotherapy T10 regimen (methotrexate, vincristine,
adriamycin)-> 60-75% survival
Chemotherapy continues for 12 months in 4/52 cycles
Radiotherapy -> palliation of local pain and to treat surgically
inaccessible lesions and painful metastatic deposits
radiotherapy may also be used pre-operatively to decrease
the size and vascularity of the tumour.
Surgery:
Wide resection / Amputation

41. TUMOURS 41
Chondrosarcoma
 Primary malignant tumour whose
cells produce cartilage matrix
 May arise de novo or secondarily
to an existing benign
cartilaginous tumour

42. TUMOURS 42
Chondrosarcoma
Incidence
 17% of primary malignant
bone tumours
 Peak incidence 30 - 60
years
 Male : Female 2:1
 Sites:
 Pelvis 30%
 Femur 20%
 Femoral head 10%
 Ribs 10%

43. TUMOURS 43
Chondrosarcoma
Clinical Presentation
 Usually occurs in the metaphysis or
diaphysis
 Presents with constant ache or
increased size of a pre-existing lump
 Metastatic deposits are infrequent
and usually go to lung

44. TUMOURS 44
Chondrosarcoma
X-Rays
 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
 Chondrosarcoma can also be classified as:
 Intramedullary, which generally arise from
enchondromas
 Patients with Ollier's disease (multiple
enchondromatosis) or Maffucci's syndrome (multiple
enchondromas and hemangiomas) are at much higher risk
of chondrosarcoma than the normal population
 Surface which arise from osteochondromas/ exostoses.
 Malignant change in an osteochondroma: increased size,
fuzzy outline, cartilage cap more than 1cm thick, base
more than 6cm diameter

45. TUMOURS 45
Chondrosarcoma

46. TUMOURS 46
Chondrosarcoma
Pathology
 Cellular
pleomorphism
and increased
cellularity with
focally calcified
matrix

47. TUMOURS 47
Chondrosarcoma
Treatment
 These tumours tend to metastasise late
therefore attempt wide local excision initially
 Radiotherapy useful for the treatment of
surgically inaccessible sites however are
relatively resistant to chemotherapy and
radiotherapy
Prognosis
 Dependant on grade:
 Low grade -> 65 - 85% 5 year survival
 High grade -> 15 - 25% 5 year survival

48. TUMOURS 48
Multiple Myeloma
(MM)
 Malignant tumor of plasma cells that
causes widespread osteolytic bone
damage
 May affect any bone with
haematopoietic red marrow (spine,
skull, ribs, sternum and pelvis)
 Age 50-80 year
 M:F 2:1

49. TUMOURS 49
Multiple Myeloma
(MM)
Presentation
 Bone pain related to the deposits
 Pathological fractures
 Constitutional symptoms related to anaemia, thombocytopenia
and renal failure
 Other symptoms may include cachexia, spinal cord compression
 Amyloidosis in 20%
 Bacterial infections are common because of a lack of normal
immunoglobulin production.

50. TUMOURS 50
Multiple Myeloma
(MM)
Investigations
 FBC normochromic, normocytic anaemia
 ESR raised ++ (Often >100mm/hour)
 Hypercalcaemia (20-40%)
 Monoclonal immunoglobulin found on serum
electrophoresis (90%)
 Bence Jones proteins (light chain subunits of
immunoglobulin) prese

51. TUMOURS 51
Multiple Myeloma
(MM)
Radiology
 The radiological appearance of multiple
myeloma is characterised by irregular lytic
defects of different sizes, often described as
"punched out" and have no periosteal reaction
 Skeletal survey is the most sensitive
investigation as a bone scan can fail to have
increased uptake in 25%
 MRI is useful for delineating spinal lesions

52. TUMOURS 52
Multiple Myeloma
(MM)
Histology
 Biopsy reveals sheets of
densely packed plasma
cells
 The degree of cytological
atypia of these cells has
no prognostic value
 The osteolytic lesions are
caused by increased
osteoclastic resorption
that is stimulated by
cytokines released by the
plasma cells

53. TUMOURS 53
Multiple Myeloma
(MM)
Treatment
 Radiotherapy
 MM is sensitive to Radiotherapy, and reossification of tumour
defects may occur within several months
 Radiotherapy is recommended for intractable bone pain, it can be
dramatically effective in relieving symptoms
 Chemotherapy
 Palliative only
 Bisphosphonates useful in the treatment of hypercalcaemia.
 Surgery
 Prophylactic IM nails for femoral, humeral deposits
 ORIF of other pathological fractures
 15% may need spinal decompression due to deposits or fracture

54. TUMOURS 54
Multiple Myeloma
(MM)
Prognosis
 Untreated, a patient with bony lesions will only survive an
average of 6-12 months with the cause of death usually by
infection or haemorrhage
 Improved survival following chemotherapy
 With treatment a survival time of 3-5 years is not uncommon
 Solitary lesions - 60% 5 year survival
 Multiple lesions - 5% 5 year survival

55. TUMOURS 55
Unicameral (Simple)
Bone Cyst (UBC)
 Benign lesion which occurs during growth
 20% of benign bone lesions
 Age 5-15 years
 Not found in adults
 Sex male to female is 3:1
 The most common location is the proximal humerus (67%) followed by
the proximal femur (15%)
 UBC's may be found in unusual sites (e.g. calcaneum, pelvis) in patients
>17 years
 Cysts may be Active or Latent: Active cysts are located near the
growth plate,
but they move further away as the child grows and become inactive
(latent)

56. TUMOURS 56
Unicameral (Simple)
Bone Cyst (UBC)

57. TUMOURS 57
Unicameral (Simple)
Bone Cyst (UBC)
Presentation
 Asymptomatic
 Usually presents as a pathological
fracture (~ 65%)
Aetiology
 Unknown
 Venous obstruction leading to a
transudate of fluid
 Fluid contains high levels of IL-1 &
IL-6, which stimulate osteoclasts

58. TUMOURS 58
Unicameral (Simple)
Bone Cyst (UBC)
Radiology
 Well defined, central
osteolytic area with a
thin sclerotic margin
(‘Fallen Leaf’ appearance)
 Metaphyseal in young -
moves towards diaphysis
with growth
 It fills and slightly
expands the juxta
epiphyseal metaphysis

 CT not helpful unless the
UBC is in the pelvis

59. TUMOURS 59
Unicameral (Simple)
Bone Cyst (UBC)
Pathology
 Histologically UBC's are thin walled
cavities filled with blood tinged fluid.
 The lining cells are cuboidal, but are
not an endothelium
 There is endosteal osteoclastic
activity and periosteal new bone
formation

60. TUMOURS 60
Unicameral (Simple)
Bone Cyst (UBC)
Treatment
 Treatment goal is to minimise fracture risk until the cyst heals
(but this can take years)
 Steroid injection
1-3 percutaneous injections repeated at 2 monthly intervals
60-80% success rate
 Curettage and bone graft - 50% recurrence rate and
possibility of damage to the growth plate
 Bone marrow aspirate has recently been used
 Intramedullary fixation / stabilization with flexible nails may
help stabilize the lesion and may also promote resolution

61. TUMOURS 61
Aneurysmal Bone
Cyst (ABC)
 Benign solitary, expansile and erosive
lesion of bone
 1% of benign bone lesions
 Age most frequent in children (85%
cases <20 years old)
 Sex female to male is 2:1
 ABC's can be found in any bone in
the body
 The most common location is the
metaphysis of the lower extremity
long bones, more so than the upper
extremity
 The vertebral bodies or arches of
the spine may be involved
 Approximately one-half of lesions in
flat bones occur in the pelvis

62. TUMOURS 62
Aneurysmal Bone
Cyst (ABC)
Presentation
 Swelling, tenderness and pain
 Occasionally there is limited range of motion
due to joint obstruction
 Spinal lesions can cause neurological symptoms
secondary to cord compression
 Pathological fractures are rare due to the
eccentric location of the lesion

63. TUMOURS 63
Aneurysmal Bone
Cyst (ABC)
Differential diagnosis
Depending on the location, the
differential includes
 UBC,
 chondromyxoid fibroma,
 giant cell tumor,
 osteoblastoma
 highly malignant telangiectatic
osteosarcoma.

64. TUMOURS 64
Aneurysmal Bone
Cyst (ABC)
Radiographic features
 On plain film, an ABC is normally placed
eccentrically in the metaphysis and
appears osteolytic
 The periosteum is elevated and the
cortex is eroded to a thin margin
 The expansile nature of the lesion is
often reflected by a "blow-out" or
"soap bubble" appearance
 CT scan can help delineate lesions in the
pelvis or spine where plain film imaging
may be inadequate
 CT scan can narrow the differential
diagnosis of ABC by demonstrating
multiple fluid-fluid levels within the
cystic spaces
 MRI can also confirm the multiple fluid-
fluid levels

65. TUMOURS 65
Aneurysmal Bone
Cyst (ABC)
Pathology
 Macroscopically, an ABC is like a blood filled sponge
with a thin periosteal membrane. Soft, fibrous walls
separate spaces filled with friable blood clot.
 Microscopically, the ABC has cystic spaces filled
with blood. The fibrous septa have immature woven
bone trabeculae as well as macrophages filled with
haemosiderin, fibroblasts, capillaries and giant
cells.

66. TUMOURS 66
Aneurysmal Bone
Cyst (ABC)
Treatment
 The treatment approach will vary depending of the location and
aggressiveness of the lesion
 A slow growing, indolent ABC has been observed to regress
spontaneously
 Most lesions can be treated with curettage and application of a high-
speed burr
 Local recurrence rates vary widely,
 Recurrence statistically related to young age and open growth
plates, and may be less likely following wide excision than following
curettage

67. TUMOURS 67
Fibrous Dysplasia
(FD)
Normal medullary bone is
replaced by variable amounts of
structurally weak fibrous &
osseous tissue

68. TUMOURS 68
Fibrous Dysplasia
(FD)
Aetiology
 ? developmental hamartoma
Incidence
 5 - 20% benign bone lesions
 Relatively common and usually monostotic
 Affects children and adolescents
 Median age at onset 8 years
 Male > Female ( Albrights - Female > Male)

69. TUMOURS 69
Fibrous Dysplasia
(FD)
Sites
 Ribs commonest (40%)
 Lower limbs more than upper limbs
 Craniofacial -> skull deformity
 Epiphyses usually spared
 Polyostotic -> pain, fracture (85%), deformity and skin
pigmentation

70. TUMOURS 70
Fibrous Dysplasia
(FD)
X-Rays
 Lucent lesion in
medullary space
 Sclerotic margin with
no discernable matrix.
 Ground glass
appearance typical
 No periosteal reaction
 Shepherds crook
deformity of proximal
femur caused by
repeated # through
proximal femur lesions

71. TUMOURS 71
Fibrous Dysplasia
(FD)
Pathology
 Bone replaced by firm, whitish tissue of gritty
consistency
 Vascular tumour with poorly orientated bone
trabeculae separated by fibrous tissue.
 Bone is woven rather than lamellar
 lack of osteoblastic rimming of trabeculae

72. TUMOURS 72
Fibrous Dysplasia
(FD)
Differential Diagnosis
 Hyperparathyroidism
 osteoblastoma
 osteosarcoma

73. TUMOURS 73
Fibrous Dysplasia
(FD)
Treatment
 Monostotic -> curettage and grafting if
symptomatic
 Polyostotic -> symptomatic treatment
 May require osteotomy for deformity or
lengthening / shortening procedures

74. TUMOURS 74
Fibrous Dysplasia
Prognosis
 Monostotic lesions cease activity at
puberty but may be reactivated by
pregnancy
 Polyostotic - 85% -> pathological
fracture
 malignant change occurs after
radiotherapy

75. TUMOURS 75
Summary
 Primary bone tumours are relatively rare
 Osteosarcoma is the Commonest malignant primary
bone tumour
 Exostoses are the most common benign bone
tumours
 Patients with bone tumours need a thorough work
up.

76. JULY 2007 TUMOURS 76