Bone tumors

1. BENIGN BONE TUMORS
-Dr.N.Suriyaprakash
JR–Dept of radiodiagnosis

3. CLASSIFICATION OF PRIMARY
BENIGN BONE TUMORS

4. RADIOLOGICAL ASSESSMENT OF BONE TUMORS
• Location
• Rate of growth
• Perioseal reaction
• Matrix mineralisation

7. PATTERNS OF PERIOSTEAL REACTION

8. PATTERNS OF MATRIX MINERALISATION

9. CARTILAGE TUMORS
Osteochondroma
Enchondroma
Chondroblastoma
Chondromyxoid fibroma
Fibrocartilaginous
mesenchymoma
Radiolucent matrix
Scalloped margins
Annular, comma-shaped, or punctate
calcifications

10. OSTEOCHONDROMA
Highest incidence is in the second decade
• Lesion is characterized by a cartilage-capped bony
projection on the external surface of a bone.
Commonest locations - distal femur, proximal humerus,
proximal tibia and proximal femur

11. Presentation
Mechanical problems such as an enlarging mass,
pressure on adjoining structures (muscles, nerves,
vessels), or rarely with fracture of the bony stem.
Irritation of overlying soft tissues may result in
adventitial bursa formation, which can mimic
sarcomatous degeneration
Lesions may be classified as either pedunculated or sessile

13.  Uninterrupted merging of the cortex of the host
bone with the cortex of the osteochondroma
 Medullary portion of the lesion and the
medullary cavity of the adjacent bone
communicate.
 Calcifications in the chondro-osseous portion of the
stalk of the lesion and cartilaginous cap

15. CT
• Lack of cortical interruption and the continuity of
cancellous portions of the lesion and the host bone
MRI
• Cartilaginous cap shows high signal intensity on T2-
weighted and gradient echo sequences.
• Narrow band of low signal intensity surrounding the cap
represents the overlying perichondrium

18. COMPLICATIONS
• Pressure on nerves or blood vessels
• Pressure on the adjacent bone with occasional fracture
• Inflammatory changes of the bursa exostotica (“exostosis
bursata”) covering the cartilaginous cap
• Malignant transformation to chondrosarcoma

20. Bursa exostotica. (A) A 25-year-old man with a known solitary osteochondroma of
the distal right femur reported gradually increasing pain. The capillary phase of
an arteriogram reveals a huge bursa exostotica. Inflammation of the bursa, with
the accumulation of a large amount of fluid (bursitis), was the
cause of the patient's symptoms.

21. TREATMENT
• Solitary lesions of osteochondroma usually can
simply be monitored if they do not cause clinical
problems.
• Surgical resection
• lesion becomes painful
• suspected encroachment on adjacent nerves
or blood vessels
• pathologic fracture

22. MULTIPLE OSTEOCARTILAGINOUS
EXOSTOSES
• A/K/A multiple hereditary osteochondromata, familial
osteochondromatosis, or diaphyseal aclasis
• Mcsites - knees, ankles, and shoulders
• The radiographic features are similar to those of single
osteochondromas lesions are more frequently of the
sessile
• CT and 3D CT show spatial distribution of the lesions

23. Anteroposterior radiograph
of the shoulder of a 22-year-
oldman demonstrates
multiple sessile lesions
involving the proximal
humerus, scapula, and ribs.
(B) Involvement
of the distal femur and
proximal tibia is
characteristic of this
disorder

24. Coronal (B) and axial (C) T1-weighted (SE; TR 600/TE 20
msec) MR images demonstrate continuity of the lesions
with the medullary portion of the femora. Note also
dysplastic changes expressed by abnormal tubulation of
the bones

25. ENCHONDROMA / CHONDROMA
• Lesion is characterized by the formation of
mature hyaline cartilage
• Affect the tubular bones of the hands and feet.
Proximal phalanges (40–50%), metacarpals (15–
30%) and middle phalanges (20–30%).
• Typically metaphyseal or diaphyseal.

26. Displacement of embryonic rests of cartilage
from growth plate into metaphysis
Eccentric
Well-circumscribed, lobular or oval lytic lesions,
which may expand the cortex
Size at presentation ranges from 10 to 50 mm

27. CT
Better advantage - scalloped cortex and matrix
calcification
Separation of a lesion from the medullary cavity

28. MRI
Depicts cartilaginous soft-tissue component.
Fat suppression or enhanced gradient-echo
sequences may improve tumor-marrow contrast.
Pitfall - marrow edema mimicking tumor invasion or
vice versa.

30. Enchondroma protuberans
arises in the intramedullary cavity of
a long bone and forms a prominent
exophytic mass on the cortical
surface.
DD
1. Osteochondroma
2. Central chondrosarcoma

34. VARIETIES OF ENCHONDROMA
 Calcifying enchondroma
 Olliers syndrome
 Endosteal chondroma
 Parastoeal chondroma - periosteal chondroma may continue to
grow after skeletal maturation
 Maffuci syndrome

35. COMPLICATIONS
• Pathological fracture
• Malignant transformation to Chondrosarcoma
Radiographic signs of the transformation
• Thickening of the cortex
• Destruction of the cortex
• Soft-tissue mass
Clinical sign - development of pain
in the absence of fracture at the site
of the lesion.

36. DIFFERENTIAL DIAGNOSIS
• Medullary bone infarct (particularly in long bones)
 sclerotic rim
• Slowly growing low-grade Chondrosarcoma (large
solitary enchondroma)
 Localized thickening of the cortex
 Deep endosteal scalloping
 Lesions longer than 4 are suggestive of malignancy

37. radiograph of the distal femur (B) and coronal T1-
weighted fat-suppressed MR image obtained after
intravenous injection of gadolinium (C) show deep
endosteal scalloping
no
endosteal
scalloping
of the
cortex,
and the
calcified
area is
surrounde
d by a
thin,
dense
sclerotic
rim, the
hallmark
of a bone
infarct.

38. TREATMENT
Curettage of the lesion with the application of
bone graft is the most common course of
treatment

39. CHONDROBLASTOMA
• Benign lesion occurring before skeletal maturity,
characteristically presenting in the epiphyses of
long bones.
• Located eccentrically, shows a sclerotic border,
and often demonstrates scattered calcifications
of the matrix

40. •Thick, solid periosteal reaction distal to the lesion
in long bones
•CT scan - demonstrate the calcifications
•MRI - reveals a larger area of involvement than can
be seen on radiography, including regional bone
marrow and soft-tissue edema

41. faint
sclerotic
border and
central
calcifications
A lesion in the proximal humerus (arrows)
elicited periosteal reaction along the lateral
cortex (open arrow).

42. Chondroblastoma. (A) Lateral radiograph and (B) anteroposterior tomogram of the knee show
the typical appearance of a chondroblastoma in the proximal epiphysis of the tibia. Note the
radiolucent, eccentrically located lesion with a thin, sclerotic margin (arrows). There are small,
scattered calcifications in the center of the lesion, which are better seen on the tomogram

43. CT section shows the calcifications clearly CT image shows the sclerotic rim and
chondral calcifications inside the

44. (A) Axial T2-weighted MRI shows sharply marginated lesion with sclerotic border
and central calcifications within the left humeral head. Note the small amount
of joint effusion and peritumoral edema.
(B) sagittal proton density-weighted and (C) axial T2-weighted
MR images of the knee show extension of chondroblastoma located in the
posterior aspect of proximal tibia into the soft tissues

45. TRATMENT & COMPLICATIONS
• Chondroblastomas are usually treated by
curettage and bone grafting. Very few cases are
treated by radiofrequency ablation.
• Rarely pulmonary metastasis can occur.

46. CHONDROMYXOID FIBROMA
• Characterized by the production of chondroid,
fibrous, and myxoid tissues in variable proportions
• Predilection for the bones of the lower extremities-
proximal tibia and distal femur

47. RADIOGRAPH
• Eccentric location
• Sclerotic scalloped margin
• Erosion / Balloning of cortex
• No obvious calcification
• Periosteal new bone formation

48. Chondromyxoid
fibroma.
Anteroposterior (A)
and lateral (B)
radiographs of the
left leg demonstrate
a radiolucent lesion
extending from the
metaphysis into the
diaphysis of the tibia,
with a geographic
type of bone
destruction and a
sclerotic scalloped
border

49. MRI of chondromyxoid fibroma. (A)
Sagittal T1-weighted MRI in a 10-
year-old girl shows a well-demarcated
lesion in the plantar aspect of the
calcaneus, displaying low signal
intensity. (B) An axial T1-weighted
image shows significant amount of
peritumoral edema. (C) Sagittal T2-
weighted MRI shows the lesion
displaying high signal intensity.
A sclerotic border is imaged as a rim of
low signal intensity

50. DIFFERENTIAL DIAGNOSIS
Buttress of periosteal new
bone formation in
chondromyxoid fibroma may
be radiographically
indistinguishable from an
aneurysmal bone cyst.
The tumor balloons out from the cortex and is supported
by a solid periosteal buttress resembling that seen in an
aneurysmal bone cyst

51. Popcorn-like, annular, or punctate
calcifications
A lobulated growth pattern with
frequent shallow scalloping of the
endosteal cortex.
Uninterrupted merging of the
lesion's cortex with the host bone
cortex
Continuity of the cancellous
portion of the lesion with the
medullary cavity of the host
Its eccentric epiphyseal location
Sclerotic margin
Scattered calcification
Periosteal reaction
Location close to the growth plate
Sclerotic scalloped margin
Butteres of periosteal new bone
Lack of visible calcifications
Benign
cartilaginous
tumor

52. OSTEOGENIC TUMORS
Osteoma
Osteoid osteoma
Osteoblastoma
Bone-forming neoplasms are characterized by the
formation of osteoid or mature bone directly by the
tumor cells.

53. OSTEOMA
• Slow-growing osteoblastic lesion commonly seen in outer
table of calvarium and in frontal and ethmoid sinuses.
• Radiographic appearance of a dense, ivory-like sclerotic
mass attached to cortex with sharply demarcated borders
• Lesions encountered in long and short tubular bones is
known as a parosteal osteoma.

54. Parosteal osteoma. Dorsovolar radiograph
of the hand demonstrates a parosteal
osteoma of the proximal phalanx of the
middle finger. A typical ivory-like mass is
seen attached to the cortex.

55. Differential diagnosis
• Parosteal osteosarcoma
• Sessile osteochondroma
• Periosteal osteoblastoma
• Ossified parosteal lipoma
• Juxtacortical myositis ossificans
• Focus of melorheostosis

56. Parosteal osteoma
Smooth borders
Well-circumscribed
Intensely
homogeneous sclerotic
appearance
Parosteal osteosarcoma
Less dense and less
homogeneous
Zone of decreased
density at the periphery

58. OSTEOID OSTEOMA
• Benign osteoblastic
lesion characterized
by a nidus of osteoid
tissue
Limited
growth
potential
Surrounded
by zone of
reactive
bone
formation
Measures
less than
1cm
Purely
radiolucent
or have a
sclerotic
center

59. CLASSIFICATION
• Cortical
• Medullary
• Subperiosteal
location in the
particular
part of the
bone
• Extracapsular
• Intracapsular

60. CLINICAL FEATURE
Most important clinical symptom of osteoid
osteoma is pain that is more severe at night and
is dramatically relieved by salicylates (aspirin)
within approximately 20 to 25 minutes

62. Osteoid osteoma may have
more than one nidus, in
which case it is called a
multicentric or MULTIFOCAL
OSTEOID OSTEOMA

63. CT – OSTEOID OSTEOMA
• Demonstrate the nidus and localize it precisely
• Exact measurement of the size of the nidus
• Vascular groove sign - Vascular channels created by
arterioles supplying the nidus of an osteoid osteoma

66. RADIONUCLIDE BONE SCAN
• Marked increase in isotope uptake
• Useful in cases with symptoms are atypical and
the initial radiographs appear normal
• Three-phase technique is recommended

67. Radionuclide bone scan shows an
increased uptake of isotope in the
supraacetabular portion of the left ilium

68. DIFFERENTIAL DIAGNOSIS
Cortical osteoid osteoma
• Stress fracture
• Cortical abscess
• Osteosarcoma
Intramedullary lesions
• Bone abscess
• Bone island

69. Stress fracture direction of the
radiolucency is perpendicular
to the long axis of the tibial
cortex.
In osteoid osteoma, the
radiolucent nidus is oriented
parallel to the cortex.
Stress fracture vs Osteoid osteoma

70. In a bone abscess, seen here in the distal femoral
metaphysis, a serpentine tract extends from an abscess
cavity toward the growth plate. This feature
distinguishes the lesion from osteoid osteoma
Cortical abscess. Lateral tomogram of the
tibia shows a radiolucent, serpentine tract
of a cortical bone abscess (arrow) that was
originally misdiagnosed as osteoid osteoma

72. COMPLICATIONS
• Accelerated bone growth
may occur if the nidus is
located near the growth
plate, particularly in young
children
• Arthritis of precocious onset

73. TREATMENT
• Complete en bloc resection of the nidus
• Intralesional curettage
• Fluoroscopically guided or CT-guided percutaneous
extraction
• Percutaneous radiofrequency thermal ablation
• Alternative to surgery
• Mech : thermal necrosis of an approximately 1-cm
sphere of tissue

75. OSTEOBLASTOMA
• lesion is histologically similar to osteoid osteoma
but characterized by a larger size - more than
1.5 cm in diameter and usually more than 2 cm.
• Age – 10 to 30 yrs
• Long bones are frequently involved but have
predilection for vertebral column

76. Osteoblastoma vs Osteoid osteoma
• Osteoblastoma is asymptomatic / pain which is
not relieved by salicylates.
• Tends toward progression and even malignant
transformation

77. RADIOGRAPH
Giant osteoid osteoma - more than 2 cm in diameter
and exhibits less reactive sclerosis and a possibly
more prominent periosteal response than does osteoid
osteoma
A blow-out expansive lesion similar to an aneurysmal
bone cyst with small radiopacities in the center.
common in lesions involving the spine
· An aggressive lesion simulating a malignant tumor
· Periosteal lesion that lacks perifocal bone sclerosis
but exhibits a thin shell of newly formed periosteal
bone

78. (A) Conventional radiograph shows a radiolucent lesion in the sternal end
of the left clavicle (arrow). (B) Axial CT image demonstrates an expansive low-attenuation
tumor (arrows) with high-attenuation foci of new bone formation

80. (C) Axial spin echo T1-weighted MR image demonstrates that the lesion is located posteromedially in the humeral
head. The cortex is destroyed and the tumor extends into the soft tissues. (D) Axial spin echo T2-weighted MR image
shows that the lesion remains of low signal intensity, indicating osseous matrix. The rim of high signal intensity
adjacent to the posterolateral margin of the tumor reflects peritumoral edema.

81. DIFFERENTIAL DIAGNOSIS

82. TREATMENT
• En bloc resection should be performed.
• Larger lesions may require additional bone
grafting and internal fixation.

83. FIBROGENIC & FIBROHISTIOCYTIC TUMORS
Desmoplastic fibroma
Fibrous cortical defect
Non ossifying fibroma
Benign fibrous histiocytoma

84. DESMOPLASTIC FIBROMA
• a/k/a intraosseous desmoid tumor
• locally aggressive tumor that occurs in individuals
younger than age 40 years
• C/F – Pain and local swelling
• Long bones (femur, tibia, fibula, humerus, and radius),
pelvis, and mandible are frequent sites of involvement

85. • SITE: Diaphysis but extends into the metaphysis
• Epiphysis is usually spared.
• Desmoplastic fibroma has no characteristic
radiographic features.

86. Expansive ,radiolucent, with sharply defined borders
the cortex of the bone may be thickened or thinned
without significant periosteal response.
Internal pseudotrabeculation is present in 90% of cases

87. Geographic pattern of bone destruction is
noted, with narrow zones of transition and
nonsclerotic margins.
Aggressive lesions of this type are marked by
bone destruction and invasion of the soft tissues

89. Radionuclide bone scan - Increase in uptake of the
radiopharmaceutical agent at site of lesion.
CT - Evaluating cortical breakthrough and tumor
extension into the soft tissues.
MRI - Assessing intraosseous and extraosseous
extension and to characterize the tumor.

90. CT section through the hip joint shows a lobulated appearance
of the tumor and a thick, sclerotic margin. The lesion extends
into the pelvic cavity, displacing the urinary bladder

91. MRI of desmoplastic fibroma. (A) Coronal T1-
weighted MRI shows the tumor in the left
femoral shaft breaking through the cortex
and extending into the soft tissues (arrows).
(B) Axial proton density MR image
demonstrates replacement of the bone
marrow by the tumor (arrow), soft-tissue
involvement, and peritumoral edema.

92. TREATMENT
• Wide excision is the treatment of choice,
• Recurrence rate is high even after complete
excision of the tumor

93. FIBROUS CORTICAL DEFECT AND NONOSSIFYING
FIBROMA
• MC fibrous lesions of bone.
• Predominantly seen in children and adolescents
• Predilection for the long bones- femur and tibia
• More common in boys than in girls

94. FIBROUS CORTICAL DEFECT
Radiolucent lesion is elliptical and confined to the
cortex of a long bone near the growth plate demarcated
by a thin margin of sclerosis
First and second decades of life
Disappear spontaneously

96. OSSIFYING FIBROMA
• When they encroach on the medullary region of a bone, they are
designated nonossifying fibroma
• Eccentrically located
• Scalloped sclerotic border
• Nonossifying fibroma may involve several bones, in which case
the condition is called disseminated nonossifying fibromatosis

98. • SKELETAL SCINTIGRAPHY - minimal to mild increase in
activity.
• COMPUTED TOMOGRAPHY
• demonstrate to better advantage the cortical
thinning and medullary involvement
• delineate early pathologic fracture more
precisely

99. CT of nonossifying fibroma. Oblique radiograph
of the right tibia of a 14-year-old girl shows an
elliptical radiolucent lesion with sclerotic border.
Axial and coronal reformatted CT images show
low attenuation lesion exhibiting a high-
attenuation scalloped border and extending into
the anterolateral cortex of tibia.

100. MAGNETIC RESONANCE IMAGING
 T1 - Intermediate to low signal intensity
 T2 - Intermediate to high signal intensity
After contrast administration, both fibrous cortical
defects and nonossifying fibromas invariably exhibit
hyperintense border and signal enhancement
Mineralization of the lesion during healing appears
predominantly as low signal intensity

101. MRI of nonossifying
fibroma. Anteroposterior
radiograph of the right
fibula of a 14-year-old girl
shows an eccentric well-
defined radiolucent lesion
with sclerotic border. Note
thinning of the medial
cortex and a pathologic
fracture (arrow). Coronal
T1-weighted MRI shows the
lesion exhibiting
intermediate signal
intensity.

102. COMPLICATIONS AND TREATMENT
• Most lesions undergo spontaneous involution (healing) by
sclerosis or remodeling
• Some larger lesions may be complicated by pathologic
fracture
• if a lesion is large, extending across 50% or more of the
medullary cavity, curettage and bone grafting is the
treatment of choice.

103. Spontaneous involution of nonossifying
fibroma in the distal tibia is
characterized by progressive sclerosis of
peripheral parts of the lesion

104. BENIGN FIBROUS HISTIOCYTOMA
• Radiographic features very similar to those of
nonossifying fibroma.
• Radiolucent, with sharply defined and frequently
sclerotic borders, without any mineralization of
the matrix

105. BFH vs NOF
Benign fibrous histiocytoma presents in older
(usually older than 25 years) than those with
nonossifying fibroma
Produce symptoms such as pain or discomfort
in the involved bone
More aggressive clinical course and may recur
after treatment

106. Benign fibrous histiocytoma. A 37-
year-old man presented with
occasional pain in the right knee.
Oblique radiograph of the knee
demonstrates a lobulated
radiolucent lesion with a well-
defined sclerotic
border, located eccentrically in the
proximal tibia. The diagnosis was
confirmed by excision biopsy

107. Anteroposterior radiograph of
the left proximal humerus in
a 26-year-old woman with
chronic arm pain shows
eccentric, well-defined,
partially sclerotic lesion

108. FIBROUS DYSPLASIA
• A/K/A fibrous osteodystrophy, osteodystrophia
fibrosa, or osteitis fibrosa disseminata
• fibroosseous lesion charecterised by aberrant
development of fibroosseous tissue replacing
normal cancellous bone

109. Fibrous
dysplasia
Monostotic Polyostotic
Characterized by the replacement of normal lamellar
cancellous bone by an abnormal fibrous tissue that contains
small, abnormally arranged trabeculae of immature woven
bone formed by metaplasia of the fibrous stroma.

110. MONOSTOTIC FIBROUS DYSPLASIA
• most commonly affects the femur(femoral
neck) as well as the tibia and ribs.
• arises centrally in the bone.
• Spares the epiphysis in children.
• As the lesion enlarges, it expands the
medullary cavity

111. Radiographic appearance of monostotic fibrous
dysplasia varies, depending on the
proportion of osseous-to-fibrous content
Greater osseous content - Dense and sclerotic
Greater fibrous content - More radiolucent,
with a characteristic ground-glass appearance

112. AP of the distal leg shows a radiolucent
lesion in the diaphysis of the tibia. slight
expansion and thinning of the cortex and
the partial loss of trabecular pattern in
the cancellous bone, which gives the
lesion a ground-glass or smoky
appearance.

113. CT - areas of high attenuation in more
sclerotic lesions and a low-attenuation matrix with
an amorphous ground-glass texture in lesions with
greater fibrous content
MRI - decreased signal on T1 and T2
sequences. The sclerotic rim (rind sign) is invariably
imaged as a band of low signal intensity on T1 anT2
sequences.

114. CT image shows a focus of fibrous dysplasia in
the neck of the femur exhibiting a typical “rind
sign”—thick sclerotic border surrounding a
radiolucent/low-attenuation lesion (arrows).
CT of fibrous dysplasia - CT section shows ground-glass
appearance of the lesion and a sclerotic highattenuation
border

115. LIPOSCLEROSING MYXOFIBROUS TUMOR
•Mimics monostotic fibrous dysplasia, particularly
when located in the intertrochanteric region of the
femur
•Benign fibroosseous lesion characterized by a
complex mixture of histologic elements that include
lipoma, fibroxanthoma, myxoma, myxofibroma, fat
necrosis, bone, and cartilage.

116. AP of the left hip
shows radiolucent
lesion with well-
defined thick
sclerosing border in
the intertrochanteric
region of the femur
(open arrows).
Coronal T2-weighted
MR image shows the
lesion (arrows) to
exhibit heterogeneous
signal intensity.
Peripheral sclerotic
“rind” displays signal
void.

117. POLYOSTOTIC FIBROUS DYSPLASIA
• More aggressive
• Predilection for one side of the body - pelvis is
frequently affected - proximal end of the femur is
a common site of involvement
• Lesions generally progress in number and size
until the end of skeletal maturation.

118. • The articular ends are usually spared
• Cortex is often thinned by the expansive component of
the lesion, and the inner cortical margins may show
scalloping
• Replacement of medullary bone by fibrous tissue leads
to a loss of the trabecular pattern, giving the lesions a
ground-glass, “milky,” or “smoky” appearance

119. Polyostotic fibrous dysplasia.
Anteroposterior radiograph of the right hip
of an 18-year-old woman shows unilateral
involvement of the ilium and femur. There
is a pathologic fracture of the femoral
neck with a varus deformity

120. CT
• Accurately delineate the extent of bone involvement
• Tissue attenuation values are usually within the 70- to
400-HU range, apparently reflecting the presence of
calcium and microscopic ossification throughout the
abnormal tissue
• Define the extent of craniofacial disease, including
impingement on orbital structures

121. Anteroposterior radiograph of the
proximal left humerus shows
expansive, mostly radiolucent
lesion (arrows) with focal
sclerotic areas at the junction of
the head and neck (open arrow).
The cortex is thinned out.
(B) CT section through the shaft
of the humerus shows a low-
attenuation lesion with minimal
scalloping of the endocortex. (C)
CT section through the shoulder
joint reveals the high-attenuation
areas of sclerosis in the humeral
head and scapula (arrows).

122. Anteroposterior radiograph of the pelvis
shows multiple lesions in the left ilium
and proximal left femur. The
involvement of the sacrum is not well
demonstrated.
CT section of the pelvis precisely shows
the extent of involvement of the ilium
and sacrum. (C) Axial CT image
of one of the thoracic vertebrae and
ribs shows multiloculated appearance
of the lesions, expansion of the
bone, pseudosepta, thinning of the
cortex, and a pathologic fracture.

123. MRI
• T1-weighted images - homogeneous, intermediate or
moderately low signal intensity
• T2 weighted images - the signal is bright or mixed.
• After intravenous injection of gadolinium, most lesions show
central contrast enhancement and some peripheral rim
enhancement

126. COMPLICATIONS
• Pathological fracture
Shepherd's crook – Femoral neck fracture
• Massive cartilage hyperplasia may be seen in this disorder,
resulting in the accumulation of cartilaginous masses in the
medullary portion of the affected bone. This condition is
commonly referred to as fibrochondrodysplasia or
fibrocartilaginous dysplasia. •Sarcomatous transformation

127. shepherd's crook”
deformity,
fibrocartilaginous
dysplasia

128. MCCUNE-ALBRIGHT SYNDROME
• When polyostotic fibrous dysplasia is
associated with endocrine
disturbances (premature sexual
development, hyperparathyroidism,
and other endocrinopathies) and
abnormal pigmentation marked by
café-au-lait spots of the skin, the
disorder is called McCune-Albright
syndrome
. Radiograph of the lower leg shows expansion of
the tibia and fibula associated with thinning of
the cortex. Note the ground-glass appearance of
the medullary portion of these bones
Axial T2-weighted MRI - abnormal signal
intensity and widening of the scapula and
abnormal signal intensity in the humeral head

129. MAZABRAUD SYNDROME
• characterized by an
association of
polyostotic fibrous
dysplasia with soft-
tissue myxomas
(B) Coronal
T1-weighted
heterogenou
signal
alteration
and
dysplastic
changes of
the right
femur.
Axial T2-
weighted
MRI of the
right thigh
demonstrat
es the
multiple
hyperintens
e
intramuscul
ar myxomas

130. GIANT CELL TUMOR

131. GIANT CELL TUMOR
• Aggressive lesion characterized by richly vascularized
tissue containing proliferating mononuclear stromal cells
and numerous uniformly distributed giant cells of
osteoclast type
• Localized to the articular end of the bone
• Preferred sites include the proximal tibia, distal femur,
distal radius, and proximal humerus

132. purely osteolytic, radiolucent
lesion with narrow zone of
transition lacking sclerotic
margins, revealing geographic
bone destruction and usually no
periosteal reaction
RADIOGRAPH

134. CT - GCT
CT demonstrates
destruction of the
cortex and the
presence of a soft-
tissue mass

135. MRI - GCT
• Better outline the lesion
• Intermediate signal intensity

137. B) Coronal T1
shows the
tumor to be of
intermediate-
to-low signal
intensity. (C)
On coronal T2-
weighted the
lesion becomes
bright,
displaying low-
signal septation

138. Giant cell tumor.
(A) Axial and (B) coronal reformatted CT images of the
right knee show a large tumor destroying the cortex
of the medial femoral condyle and extending into
the soft tissues).
(C) Coronal T1-weighted MRI demonstrates the tumor
exhibiting an intermediate, slightly heterogenous
signal due to the bleeding.
(D) Coronal T1-weighted fat-suppressed MR image
obtained after intravenous administration of
gadolinium shows marked enhancement of the
tumor.

139. DIFFERENTIALS
• Primary ABC
• Brown tumor of hyperparathyroidism
• Benign fibrous histiocytoma
• Large intraosseous ganglion
rarely affects the
articular end of a
bone
occurs in younger
age group
fluid-fluid level
demonstrated
either on CT or on
MRI examination
Skeletal
manifestations
osteopenia
cortical or
subperiosteal
resorption
Resorptive changes
at the distal
phalangeal tufts
 loss of the lamina
dura of the teeth.

140. COMPLICATIONS
• Pathologic fracture

141. TREATMENT
• Surgical curettage and bone grafting
• Wide resection with secondary implantation of an
allograft

142. (A) Conventional radiograph of the right wrist of a 32-year-old
woman shows a lytic lesion in the distal radius. (B) After extensive curettage,
postoperative radiograph shows
application of bone chips.

143. MISSCELANEOUS BENIGN LESIONS

144. SOLITARY BONE TUMOR
• A/K/A unicameral bone cyst
• Attributed to a local disturbance of bone growth
• More common in males than in females
• Seen during the first two decades of life
• Located in the proximal diaphysis of the humerus and
femur

145. • C/F - pain,swelling or stiffness at the nearest
joint
• RADIOGRAPH - radiolucent, centrally located,
well-circumscribed lesion with sclerotic margins
•No periosteal reaction
• MAGNETIC RESONANCE IMAGING - signal
characteristics of fluid: a low-to-intermediate
signal on T1-weighted images and a bright,
homogeneous signal on T2.

146. The radiolucent
lesion is centrally
located and shows
pseudosepta. Note
the slight thinning
of the cortex and
lack of periosteal
reaction

148. COMPLICATION
Pathological fracture -
piece of fractured cortex
in the interior of the
lesion—the “fallen
fragment” sign indicating
that the lesion is either
hollow or fluid-filled

149. TREATMENT
• Curettage followed by grafting with small pieces
of cancellous bone

150. Nonossifying fibroma
Bone abscess. The
periosteal reaction
in the absence of
pathologic fracture
and the extension
of the lesion into
the epiphysis favor
the diagnosis of
bone abscess.
Intraosseous ganglion

151. ANEURYSMAL BONE CYST
• Majority seen in less than 20 yrs of age
• Metaphysis of long bones is a frequent site
• Radiographic hallmark - Multicystic eccentric
expansion (blow-out) of the bone, with a buttress or
thin shell of periosteal response.

153. CT - ABC
• Determining the integrity of the cortex
• Demonstration of fluid-fluid levels -
represent the sedimentation of red
blood cells and serum within the cystic
cavities
• Demonstration of internal ridges
described on radiography as
trabeculation or septation
CT section shows its intracortical location; the lesion
balloons out from the lateral aspect of
the femur but is contained within a thin uninterrupted
shell of periosteal new bone (arrows).

154. CT of aneurysmal bone cyst. Lateral (A) and
oblique (B) radiographs of the right ankle of a 24-
year-old woman show a radiolucent, trabeculated
lesion in the talus. Coronal anterior (C) and
coronal posterior (D) CT sections demonstrate the
internal ridges of the lesion.

155. MRI of aneurysmal bone cyst.
(A) AP radiograph of the left hip shows
an expansive radiolucent lesion
destroying the ischial bone.
(B) CT section demonstrates that
the lesion broke through the medial
cortex
(C) Axial T2-weighted MR image shows
the lesion to be of high signal intensity
Multiple fluid-fluid levels characteristic
of an ABC are well demonstrated.

156. SKELETAL SCINTIGRAPHY
• reflects the vascular nature
of the lesion.
• increased uptake of
radiopharmaceutical in a ring-
like pattern around the
periphery of ABC.

157. COMPLICATION
• Long bones - Pathological fracture
• Spine – Scoliosis / Neurological deficit

158. DIFFERENTIAL DIAGNOSIS
• Solitary bone cyst
• Chondromyxoid fibroma
• Gaint Cell Tumor

159. ABC
•Eccentric
•Expansile
•Periosteal reaction
•Solid tissue +
SBC
• Central
• Less expansile
• Periosteal reaction only when
pathological fracture occurs
• Hollow fluid filled structure
• Fallen fragment sign
In thin bones, such as the ulna, fibula, metacarpals,
or metatarsals, the characteristic eccentricity of
ABC may be lost and, conversely, SBC may
demonstrate expansive features

160. TREATMENT
• Surgical removal of the entire lesion +/- bone graft
• Selective arterial embolization
• Adjuvant therapy such as liquid nitrogen, phenol, or
polymethylmethacrylate
Recurrence of the lesion is frequent