2. GENERAL CHARACTERISTICS OF BONE
TUMOURS
ā¢ Age at presentation
Primary bone tumors are rare below the age of 5 years and over the
age of 40 years
Metastasis are commonest lesion over the age of 40 years.
3. RADIOLOGICAL ASSEMENT OF BONE
TUMOURS
ā¢ Location
The location of lesion within skeleton(appendicular, axial) and within
the individual bone(epiphysis, metaphysis , diaphysis;intramedullary,
intracortical, surface ) must be considered since it has a influence on
differential diagnosis
4. ā¢ Rate of growth
Lesion margin is important feature of rate of growth
In benign neoplasm margin is sharp(Geographical ; Type 1)
Type 1A has rim of sclerosis between lesion and host bone
5. ā¢ Type 1B is very well defined lytic lesion but with no marginal sclerosis
6. ā¢ Type 1C has less sharp and non-sclerotic margin
7. ā¢ Periosteal Reaction
Helps to indicate aggressiveness of lesion
(A)Solid periosteal reaction- well formed periosteal reaction
- indicate slow rate of growth
34. OSTEOGENIC TUMOURS
ā¢ Osteoid Osteoma
-Small benign vascular osteoblastic tumor
-most patients present in 2nd and 3rd decade of life and male:female
ratio is 2-3:1
-it is most common in appendicular skeleton with over 50% located in
diaphysis or metaphysis of tibia or femur
35. ā¢ Radiological features
-Characteristic feature is nidus which may appear lytic, sclerotic or most
commonly of mix density depending upon degree of central
mineralization.
-nidus is commonly surrounded by region of reactive medullary
sclerosis and solid periosteal reaction
-
36. ā¢ CT demonstrates the classical features of a round or oval soft tissue
density nidus, which commonly shows central dense mineralization.
ā¢ āvascular grove signā which is manifested by thin, serpentine channel
in the thickened bone surrounded by nidus.
37. ā¢ MRI demonstrate heterogeneously low- intermediate signal
intensities on T1WI and T2WI and enhancing strongly on
administration of intravenous contrast media
38. Osteoblastoma
- Histologically similar to osteoid osteoma and is differentiated by its
size, being typically grater than 1.5 cm in diameter
- It shows more aggressive growth pattern with potential for extra
osseous extension
- Over 80% patients are under the age of 30 years.
- Humerus is the commonest location in appendicular skeleton and the
lesion arises in the medullary cavity.
39. ā¢ Radiological features
-The lesion is predominantly lytic, measuring over 2cm in diameter, with
largest lesion showing greater degree of matrix mineralization.
-CT reveal occult calcification, which can be punctate, nodular or
generalized
-larger lesion may result in bone expansion with or without surrounding
shell of reactive bone.
40. FIBROHISTIOCYTIC TUMOURS
ā¢ Fibrous cortical defect
-It as incidental finding, appearing as cortical based lytic lesion
commonly with a thin sclerotic margins.
-Most commonly identified in the distal femur and proximal tibial
metaphysis.
-Lesion typically fade with the time.
41. ā¢ Non ossifying fibroma
Benign neoplasm which is commonly identified incidentally or may
present with pathological fracture
-patients usually presents in second decade of life and slight male
preponderance is recorded
-majority(90%) involve lower limb,particularly tibia and distal end of
femur
42. ā¢ Radiological features
-The lesions are metaphyseal or diametaphyseal and essentially
intracortical
- Lobular appearance is classical with the lesion usually enlarging into
medullary cavity.
- The tumor is oval with its long axis in the line of bone
43. ā¢ On MRI NOF shows low-intermediate SI on T2WI
ā¢ On T1WI lesion is hypointense ,but marginal with marginal or septal
hyperintensity and the remainder are hypointense
44. GIANT CELL TUMOUR
Giant cell tumor
ā¢ it is an aggressive benign neoplasm accounting for approximately 20%
benign bone tumors.
ā¢ Approximately 80% cases occurs between 18 and 45 years of age with
male : female ratio of 2:3
ā¢ The tumor nearly always occurs in subarticular or subcortical
region(adjacent to fused apophysis of long bone)
ā¢ Knee is the common site for tumor
45. ā¢ Radiological features
GCT is classically a subarticular ,eccentric, lytic lesion with geographic,
nonsclerotic margin
Poorly defined margin indicates more aggressive lesion
46. ā¢ On MRI is iso-hypointense on T1WI and shows heterogenous
hyperintensity on STIR
ā¢ Areas of hyperintensity on T1WI indicate the presence of subacute
hemorrhage
47. VASCULAR TUMOURS
ā¢ Haemangioma
-Congenital vascular malformation
-May present as isolated bone lesion
-classified histologically as capillary, cavernous, arteriovenous or
venous.
-osseous capillary hemangioma most commonly affect vertebral body
and osseous cavernous hemangioma affect the skull vault
48. ā¢ Radiological features
-In vertebral lesions fine or coarse vertical trabeculation is seen.
-hemangioma involving the epiphyses or metaphyses linear striation
running along the axis of long bone
CT demonstrates the thickened trabeculae as dense ādotā with in fatty
matrix
57. ā¢Fibrous Dysplasia
May either momostotic or polyostotic
75% cases present before age of 30 years
ā¢ Radiological feature
-Geographic lesion that may cause bone expansion and
deformity with diffuse ground glass matrix mineralization
-Thick sclerotic margin ārind signā is characteristic
-Metadiaphyseal region is typically affected
58. ā¢ CT
Demonstrates the ground glass matrix
ā¢ MRI
On T1WI lesions are isointense but may shows areas of mild
hyperintensity due to hemorrhage.
On T2WI lesions may be isointense or hyperintense
