Includes all the reactive, benign and malignant lesions of bone with gaint cells in HPE

1. PRESENTER - DR SHREYA PRABHU
MODERATOR-DR SHWETHA J
1

2. NORMAL ANATOMY
Adult bones are classified
according to their shape-
long, flat and short bones
Long bones are divided into
three regions:- diaphysis,
metaphysis and epiphysis.
2

3. 3

4. HISTOLOGY OF BONE
Cells in bone:-
• Osteoblasts
• Osteoclasts
• Osteocytes
4

5. 5
OSTEOCY
TE

6. • A giant cell is a cell that is larger in dimension than
the cells that are routinely encountered in histology.
• These cells are involved in many physiologic and
pathological processes.
• A multinucleated giant cell (MGCs) is formed by the
union of several distinct cells.
• They are usually of monocyte-macrophage lineage
6
GIANT CELL

7. • In chronic inflammation when macrophages fail to
deal with particles that has to be removed; fuse
together and form multinucleated giant cells.
• Thus, their role in elimination of foreign substances,
damaged tissue, pathogens is essential for host
survival.
• These cells sequester persistent pathogens and
prevent further spread of infection.
• They were first reported in tuberculous granulomas
by Rokitansky and Langhans
7

8. • These types of cells differ markedly in their
• Association with disease states
• Location and prevalence in various tissues or
organs
• Stimuli that induce the formation
• Subsequent function of these cells
• The size of giant cells varies greatly, but is usually
between 40 μm and 120 μm.
8

9. NORMAL
OCCURING
REACTIVE NEOPLASTIC
Megakaryocytes Foreign body
giant cells
RS cell
Trophoblasts Langhan’s giant
cells
GC of GCT
Osteoclasts Ascoff’s giant
cells
Touton giant
cells
9

10. • Osteoclasts are bone-resorbing cells that play a
pivotal role in bone homeostasis and remodeling.
• Osteoclast precursors are derived from bone
marrow as early mononuclear macrophages, which
circulate in blood, and bind to the surface of bone.
• Osteoclast formation is driven mainly by two
cytokines, Receptor Activator of Nuclear Factor
Kappa β Ligand (RANKL) and macrophage - colony
stimulating factor (M-CSF).
11
OSTEOCLASTS

11. • In addition a wide variety of factors like systemic
hormones and growth factors influence the
formation and function of osteoclasts.
• They usually contain 10 to 20 nuclei per cell and are
found on
• bone surfaces
• on the endosteal surfaces within the haversian
system
• on the periosteal surface beneath the periosteum
12

12. GIANT CELL
LESIONS OF
BONE
13

13. 14
REACTIVE BENIGN MALIGNANT
Brown tumor GC Tumor Osteosarcoma
GC reparative
granuloma
Aneurysmal Bone Cyst Clear cell
chondrosarcoma
Pseudomalignant
myositis ossificans
Chondroblastoma Metastatic Carcinoma
Tubercular
osteomyelitis
Chondromyxoid Fibroma
Non ossifying Fibroma
Langerhans Cell
Histiocytosis
Benign fibrous
histiocytoma of bone

14. REACTIVE
GC LESIONS
15

15. • A benign, reactive, intraosseous proliferation
characterized by aggregates of giant cells in a
fibrovascular stroma
• May occur in normal bone or in pre-existing lesions,
such as brown tumor
• Site- Craniofacial, small bones of hands and feet
• Pain and swelling
• Usually treated with simple curettage
16
GIANT CELL REPARATIVE
GRANULOMA

16. 17

17. 18
Gross specimen shows a large red-brown
lesion, friable, gritty

18. 19
appearance of a lesion that contains several multinucleated
giant cells in a fibrogenic stroma and osteoid

19. 20
a.Clusters of spindle admixed with multinucleated giant cells.
b Scattered osteoblast-like cells are seen among the spindle cells and multinucleated
giant cells (arrow)

20. D/D:
 Brown tumor
 GCT
 ABC
 Non ossifying fibroma
 Ossifying fibroma
21

21. • Reactive, often self-healing lesion, characterized by
heterotopic ossification.
• In adolescents and young adults, typically after
trauma
• Radiologically, mature lesions have a very
characteristic zonal ossification pattern with a shell
of calcifications at the periphery of a well
demarcated mass
22
PSEUDOMALIGNANT MYOSITIS
OSSIFICANS

22. Histologically-
The central part is made up of fibrovascular tissue
exhibiting reactive myofibroblasts, ganglion-cell-like
large cells with prominent nucleoli, reactive osteoblasts
and multinucleated osteoclast-like cells
23

23.  The cytological features of PMO are
• Osteoblast-like cells
• Proliferating myofibroblasts
• Osteoclast-like multinucleated giant cells
• Small calcifications
 Differential diagnosis- Osteosarcoma
 Important diagnostic sign- The zonal ossification
pattern
24

24. 25
a) A mixture of reactive
osteoblasts and myofibroblasts
b) Reactive osteoblasts
c) A multinucleated
osteoclast-like giant cell and
reactive osteoblasts

25. • Bone tumor composed of non neoplastic reactive
tissue that occurs in setting of primary, secondary, or
tertiary hyperparathyroidism
• Causes-
• Adenoma
• Chief cell hyperplasia
• PTH receptor on OB activates RANKL
RANKL binds to RANK on OC OC activation
26
BROWN TUMOR OF
HYPERPARATHYROIDISM

26. • 3rd and 4th decades of life
• Females
• May be solitary or multiple
• SITE- pelvis, ribs, clavicles, and extremities(dia- or
metaphyseal)
• Painful mass
27

27. BIOCHEMICALLY-
 Hypercalcemia
 Hypophosphatemia
 Hypercalciuria
 Lowering of renal phosphate threshold
 Elevated PTH
 Elevated VIT D
 Enhanced excretion of nephrogenous cAMP
 Elevated serum ALP
28

28. Expansile, well
circumscribed, lytic, and
thin with subtle
osteopenia
29

29. 30
Severe osteopenia with resorption of
tufts
Subperiosteal resorption of the proximal
and middle phalanges
A lytic lesion in the 5th proximal phalanx
Lateral view of the skull shows
significant osteoporosis producing
a salt and pepper appearance of
the cortices

30. Well-circumscribed, reddish-brown hemorrhagic mass with lobular architecture
Thins and expands cortex
Large, blood-filled cysts may develop (osteitis fibrosa cystica)
Peripheral shell of reactive bone may be present
31

31. 33

32. 34

33. 35

34. 36
Dispersed or clustered spindle cells, and variable amounts of
osteoclast-like giant cells and haemosiderin-laden macrophages

35. D/D-
• CGCG
• GCT
• Solid ABC
• Metastatic carcinoma
37

36. BENIGN GC
LESIONS
38

37. • A benign but locally aggressive neoplasm composed
of uniformly distributed osteoclast-like giant cells
(osteoclastoma)
• 20% of benign bone tumors
• Driver mutation in H3F3A histone gene
• Develops in skeletally mature individuals during 3rd-
5th
• Most common in female
39
GIANT CELL TUMOR

38. PATHOGENESIS
• Neoplastic cells express high levels of RANKL,
which promotes the proliferation of osteoclast
precursors and their differentiation into mature
osteoclast via RANK expressed by these cells.
• Feedback between osteoclast and osteoblast that
normally regulates this process during bone
remodelling is absent
• Results is localised but highly destructive resorption
of bone matrix by reactive osteoclast.
40

39. LOCATION
75%
41

40. MOST COMMON SITES
DIST. FEMUR
PROX. TIBIA
DIST. RADIUS
42

41. RADIOLOGY
Eccentric lytic / cystic lesion
of a long bone
No evidence of periosteal lifting
No sclerotic rim
43

42. Highly variable gross
appearance, can range
from predominantly
hemorrhagic to soft and
fleshy
Typically, sharp margin
between the tumor and
surrounding bone
Surrounding bone is
typically expanded with a
thinned cortex
44
GROSS

43. 45

44. 46
Feature that might suggest malignant
behavior but have no prognostic
significance-intravascular invasion

45. 47
Necrosis spindle cell–rich areas

46. 48

47. 49

48. IMMUNOHISTOCHEMISTRY-
• Giant cells have immunoprofile similar to
macrophages
• Osteoclast-type giant cells stain for RANK
• Many of stromal mononuclear tumor cells stain for
RANKL, indicating that they may have osteoblastic
phenotype
• Mononuclear tumor cells show nuclear staining for
p63
50

49. MALIGNANCY IN GCT
• GCT- regarded as low grade malignancies due to its
tendency to recur and occasional capacity to
metastasize
• High-grade sarcoma is seen developing at the site of
a previously treated GCT
• PRIMARY MALIGNANT GCT-
• Tumor that contains foci of GCT and pleomorphic
sarcoma at first diagnosis (dedifferentiated GCT)
• SECONDARY MALIGNANT GCT-
• Initial tumor has appearance of classic GCT and
sarcomatous transformation occurs after local
recurrence/ following RT
51

50. A diagnosis of a lesion other than giant cell tumor
should be favored if:
• The patient is a child
• The lesion is located in the metaphysis or diaphysis
of a long bone rather than the epiphysis
• The lesion is multiple
• The lesion is located in the vertebrae, jaw (except
for patients with paget disease), or bones of the
hands or feet
52

51. D/D-
• Giant cell–reparative granuloma
• Brown tumor of hyperparathyroidism
• Aneurysmal bone cyst, especially solid variant
• Osteosarcoma with giant cells
• Metaphyseal fibrous defect
53

52. • Destructive, expansile benign neoplasm of bone
characterized by multiloculated, blood-filled cystic
spaces
• Cytogenetic and molecular studies document
presence of t(16;17)
54
ANEURYSMAL BONE
CYST

53. CLINICAL FEATURES
• Commonly seen in 2nd and 3rd decade of life
• Commonly affects females
• SITE-
• Metaphysis of long bones of upper and lower
extremities
• Posterior elements of vertebra
• Small bones of hands and feet
• Craniofacial skeleton
55

54. Presentation
• Pain
• Swelling
• Limitation of range of motion
• Palpable mass
• Heralding event may be pathological fracture
• Tumors in spine can cause nerve compression and
neurologic symptoms
56

55. 57

56. 58

57. 59

58. 60
1) Low-power appearance it contains several twisted septa of varying sizes.
2) Loose slender spindle cell proliferation within the cyst wall is accompanied
by multinucleated giant cells

59. 61
A) Osteoid peripherally and within the fibrous septae.
B) The bone is often densely calcified, so-called blue bone.

60. 62
• Clusters of osteoclast-like multinucleated giant cells with loose spindly stroma to cellular
stroma.
• The cell block shows fragments of bland-appearing fibroconnective tissue with fibroblasts,
myofibroblasts; histiocytes, and giant cells without endothelium

61. IMMUNOHISTOCHEMISTRY-
• There are no specific immunohistochemical findings
in ABC;
p63 can stain some tumor cells
• Spindle fibroblast-like cells may express smooth
muscle actin
• Osteoclasts stain with CD68
GENETIC TESTING-
• FISH using break-apart probe for USP6 can detect
rearrangement
63

62. D/D:
• GCT
• Solitary bone cyst
• Hemangioma
• Telangiectatic OS
• CGCG
64

63. • Extremely common, present in 30% to 50% of
children older than 2 years
• Arise eccentrically in the metaphysis of the distal
femur and proximal tibia
• Half are bilateral or multiple
• Often small, that grow to 5 or 6 cm in size are
classified as Nonossifying fibromas
65
FIBROUS CORTICAL DEFECT AND
NONOSSIFYING FIBROMA

64. 66
Both fibrous cortical
defect and
nonossifying fibroma
produce sharply
demarcated
radiolucencies,
surrounded by a thin
rim of sclerosis

65. The solid red-brown
tumor has resulted in
expansion of the bone
and thinning of the
cortex.
67

66. 68
They consist of
gray to yellow-
brown cellular
lesions containing
fibroblasts and
macrophages.
The cytologically
bland fibroblasts
are frequently
arranged in a
storiform
(pinwheel) pattern,
and the
macrophages may
take the form of
clustered cells
with foamy
cytoplasm or
multinucleated
giant cells
Hemosiderin is
commonly present

67. 69

68. D/D-
• GCT
• Solid ABC
70

69. • Group of conditions designated as Langerhans cell
histiocytosis (histiocytosis X, eosinophilic
granuloma) is an infiltration by a cell of the
accessory immune system known as Langerhans
cell, accompanied by a variable admixture of
eosinophils, giant cells, neutrophils, foamy cells, and
areas of fibrosis
• Site
• Skull>femur>pelvis>ribs
• Young adults
71
LANGERHANS CELL
HISTIOCYTOSIS

70. LCH OF BONE-
• Solitary bone involvement (Most common)
• Multiple bone involvement (with or without skin
involvement)
• Multiple organ involvement (Hand–Schüller–
Christian, Letterer-Siwe disease)
72

71. 73

72. 74

73. 75

74. 76
Histiocytes with abundant cytoplasm
and rounded or
ovoid nuclei mixed with neutrophilic
and eosinophilic leucocytes.
Lobulated or ‘coffee-bean’ nuclei

75. 77

76. 78

77. • Main differential diagnosis
• Granulomatous inflammation
• Osteomyelitis
• Hodgkin lymphoma
• Osseous manifestations of Rosai-Dorfman disease
• Survival in unifocal disease is greater than 95%;
with two organs involved, survival is 75% and
decreases with increasing number of affected sites
involvement (bone, liver, spleen, and others).
• Absence of bone lesions in multiorgan involvement
is a poor prognostic sign
79

78. • Benign primary bone neoplasia
• Female>male, 3rd-4th decade
• SITE-the spine and long bones, in a non-
metaphyseal location
• Asymptomatic/ local pain
• Excellent prognosis, curettage/ simple excision
80
BENIGN FIBROUS HISTIOCYTOMA
OF BONE

79. 82

80. 83

81. D/D-
• Non ossifying fibroma
• GCT
• Malignant fibrous histiocytoma
84

82. • Benign neoplasm, rare (<1%)
• Skeletally immature individuals, 10-25 years
• Arises in the epiphyseal end of long bones
before the epiphyseal cartilage has disappeared
• Distal end of the femur
• Proximal end of the humerus
• Proximal end of the tibia
85
CHONDROBLASTOMA

83. Intramedullary, well-defined tumor with sclerotic margins, radiolucent
with internal calcifications
86

84. Gray-pink, well circumscribed firm tissue with gritty calcifications and
hemorrhage, <5 cm, sharply marginated from surrounding bone
87

85. 88

86. 89

87. 90
Chicken wire
calcification

88. 91
1. Fragments of chondroid matrix
2. Double cell population

89. • S 100 protein,
• vimentin
92
IHC

90. D/D-
• Giant cell tumor
• Primary aneurysmal bone cyst
• Chondromyxoid fibroma
• Clear cell chondrosarcoma
93

91. • Rare benign tumor
• Long bones
• Young adults- 2nd to 3rd decade of life
94
CHONDROMYXOID
FIBROMA

92. 95

93. 96

94. 97

95. 98

96. Coarse calcifications
99

97. 100
a) Clustered spindly or stellate cells in
a myxoid background.
b) The spindly and stellate cells exhibit
moderate anisokaryosis
c) Chondroblast like cells in the myxoid
background show moderate
pleomorphism

98. IHC
• S100- cartilaginous areas and sometimes myxoid
regions
• SOX9
• Negative for keratin
101

99. D/D-
• Chondroblastoma
• Enchondroma
• Low-grade chondrosarcoma
• Chondromyxoid fibroma-like osteosarcoma
• Fibromyxoma
• Osteochondromyxoma
102

100. 103

101. MALIGNANT
GC LESIONS
104

102. • Malignant tumor in which the cancerous cells
produce osteoid matrix or mineralized bone
• Most common primary malignant tumor of bone
• Occurs in all age groups, but has bimodal age group
• Male>female
105
OSTEOSARCOMA

103. SITE -
Metaphyseal region of the long bones:-
• Lower end of femur
• Upper end of tibia
• Upper end of humerus
106

104. PREDISPOSING FACTORS-
• Paget disease
• Radiation exposure
• Chemotheraphy
• Preexisting benign bone lesions
• Foreign bodies
• Genetic predisposition
107

105. Several subtypes
• Site of origin (intramedullary, intracortical, or
surface)
• Histologic grade (low, high)
• Primary (underlying bone is unremarkable) or
secondary to preexisting disorders (benign
tumors, Paget disease, bone infarcts, previous
radiation)
• Histologic features (osteoblastic,
chondroblastic, fibroblastic, telangiectatic, small
cell, and giant cell)
• The most common subtype arises in the metaphysis
of long bones and is primary, intramedullary,
osteoblastic, and high grade
108

106. 109

107. 110

108. Infiltrative, large, intramedullary
lesion
Can be pure osteoblastic, pure
osteolytic, or mixed lytic and
blastic
Cortical destruction and soft tissue
tumor extension are common
Codman triangle (i.e., periosteal
elevation) is seen due to tumor
growth
Sunburst configuration is tumor
growth occurring in a radial fashion
112

109. Distal femoral osteosarcoma
with prominent bone formation
extending into the soft tissues.
The periosteum, which has
been lifted, has laid down a
proximal triangular shell of
reactive bone known as a
Codman triangle (arrow).
Soft tissue component has
cloud like appearance
113

110. Gigantic mass in the proximal humerus distorting the shoulder region. The
overlying skin is attenuated, and large veins that feed and drain the tumor are
visible
114

111. Often large (>5 cm), fleshy or
hard tumor, centered within the
metaphysis
Crosses the cortex with an
associated soft tissue
component
Depending on predominant
stromal component, can be
gray-tan and granular
(osteoblastic osteosarcoma)
or translucent bluish
(chondroblastic osteosarcoma)
or
a firm off-white mass
(fibroblastic osteosarcoma)
115
GROSS

112. MICROSCOPY
• Admixture of 2 elements in varying proportions-
 High grade sarcoma with epithelioid,
plasmacytoid, fusiform, ovoid, small round cells,
Clear cells, mono- or multinucleated giant cells,
spindle cells
 Bone produced by tumor cells
• Many osteosarcomas contain benign giant cells that
have the appearance of osteoclasts
116

113. 118

114. 119

115. CYTOLOGY-
• Variable cellularity
• Tumour cells-pleomorphic spindle, rounded, ovoid,
polygonal and often large, osteoblast like
• Multinucleated tumour giant cells.
• Strands of osteoid matrix between tumour cells in
clusters.
• Atypical mitosis
• Benign osteoclast-like giant cells are numerous in
giant-cell-rich osteosarcoma.
• Occasional necrosis and calcifications
120

116. 121

117. 122

118. IHC
• Exhibit strong alkaline phosphatase activity
• Immunoprofile is nonspecific
• SATB2- nuclear transcriptor factor- stains OB-
sensitive not specific
• May be positive for keratin and EMA
• Cartilagenous area S100 positive
123

119. 124
Strong positive cytoplasmic
staining for ALP
Expression of (B) osteonectin and (C)
osteocalcin in tumor cells

120. D/D-
• Dedifferentiated chondrosarcoma
• Fibrosarcoma
• Ewing sarcoma
• Osteoblastoma
• Undifferentiated pleomorphic sarcoma (so-called
malignant fibrous histiocytoma)
125

121. CHONDROSARCOMA
• Malignant tumor of chondroid differentiation
• 2nd most common, axial skeleton
• Divided into 2 major categories on the basis of
microscopic criteria:-
Conventional chondrosarcoma
Chondrosarcoma variant-
 Clear cell chondrosarcoma
 Myxoid chondrosarcoma
 Dedifferentiated chondrosarcoma
 Mesenchymal chondrosarcoma
126

122. 127
CENTRAL
CHONDROSARCO
MA
PERIPHERAL
CHONDROSARCOMA
JUXTACORTICAL
CHONDROSARCO
MA
Location Medullary cavity of
flat or long bones
De novo or from
cartilaginous cap
Of a pre-existing
osteochondroma
Shaft or long bones
Radiogra
phy
Osteolytic lesion
with splotchy
calcification
Ill defined margins
Fusiform thickening
of the shaft
Perforation of the
cortex
Presents as large
tumors with a heavily
calcified centre
surrounded by a lesser
denser periphery with
splotchy calcification
Cartilaginous lobular
pattern with areas of
spotty calcification
and endochondral
ossification
CONVENTIONAL

123. CLEAR CELL CHONDROSARCOMA
• A low-grade, cartilage-producing cells with
characteristic large, clear cytoplasm
• Rarest variant
• Younger patients
• SITE- epiphysis of proximal femur, proximal
humerus, and distal femur
• Tender mass
• Pulmonary metastases
• En bloc resection typically curative
129

124. • Epiphyseal (unique among chondrosarcomas)
• Osteolytic or sclerotic
• Often circumscribed or marginated, suggesting a benign lesion such as chondroblastoma
• Larger tumors may have soft tissue extension and cortical destruction
130

125. Gross-
• Large bulky tumors
• Pale blue matrix, softer than normal
hyaline cartilage
• Abundant gritty calcifications
• Cysts may be present
• Larger tumors may be destructive
with extensive soft tissue
component
131
This femoral head-CC-CSA-extends to the subchondral bone
plate.The well circumscribed, oval tumor is heterogeneous with
gray glistening,white,and hemorrhagic areas

126. 132

127. • Small cartilaginous
fragments in a
background of myxoid
matrix.
• Large tumour cells have
well demarcated,
abundant vacuolated
cytoplasm and
hyperchromatic nuclei
with central nucleoli.
• Occasional osteoclast-
like giant cells
133

128. IMMUNOHISTOCHEMISTRY
• Cells express S100 protein and collagen II
ELECTRON MICROSCOPY
• Ultrastructurally, neoplastic cells contain abundant
intracytoplasmic glycogen
GENETICS
• Lacks IDH1 and IDH2 mutations
134

129. D/D-
• Chondroblastic osteosarcoma
• Conventional chondrosarcoma
• Chondroblastoma (radiographic)
• Metastatic clear renal cell carcinoma
135

130. • More common than primary bone tumors
• Most common primary sites are lung, breast,
prostate, kidney, and thyroid
• Commonly involved bones include skull, spine, ribs,
pelvis, humerus, and femur
• Pain, pathologic fractures
136
METASTATIC
TUMORS

131. RADIOGRAPHY
• Lesions may be entirely sclerotic or lytic or mixture
of sclerotic and lytic
• Typically lytic metastases: Renal cell carcinoma and
thyroid carcinoma
• Typically sclerotic metastases: Prostate, breast, and
neuroendocrine carcinomas
• PET/CT is very sensitive for detection of bone
metastasis
137

132. 138

133. 139

134. HISTOLOGY
• Morphology generally resembles primary lesion
• Osteoblastic metastasis shows abundant reactive
woven bone
• Unlike osteosarcoma, bone is lined by plump,
benign appearing osteoblasts
• Secondary changes, including hemorrhage, fibrosis,
and osteoclast-type giant cell reaction, are common
• Common metastatic lesions in children:
Neuroblastoma, rhabdomyosarcoma
140

135. 141
The lack of cohesive nests of tumor
cells and their spindled character raises
the possibility of a primary sarcoma
Metastatic mammary carcinoma to
bone

136. • Foreign cell
population
• Cell clusters, acinar or
gland like
• Cells with criteria of
malignancy
142
CYTOLOGY

137. D/D-
• Osteosarcoma
• Epithelioid vascular tumors
143

138. REFERENCES
1. Fletcher C.D.M., Unni K.K., Mertens F. (Eds.): World Health Organization
Classification of Tumours. Pathology and Genetics of Tumours of Soft Tissue and Bone.
IARC Press: Lyon 2002
2. Rosai, Juan, and Lauren Vedder Ackerman. Rosai And Ackerman's Surgical
Pathology.24, Bone and joints (2014-1059); 10th ed. Edinburgh: Mosby Elsevier, 2011.
3. Fletcher C, Carrie Y. Inwards, André M. Oliveira. Chapter 25 Tumors of the
Osteoarticular System. Diagnostic histopathology of tumors. Philadelphia, PA:
Saunders/Elsevier; 2013; (p 1884-1890)
4. Field, Andrew S, and Svante R Orell. Orell & Sterrett's Fine Needle Aspiration
Cytology. 1st ed. Elsevier, 2012. Bone, (412-427)
5. Kumar v, Abbas K A, Aster C J. Robbins and cotran pathological basis of disease.
Bones, joints, and soft tissue. 9th ed. New delhi : Elsevier ; 2014
6. Nielsen, Rosenberg: Diagnostic pathology bone. Bone tumors, 2nd edition
7. Andrew H, Thomas: High yield pathology, bone and soft tissue pathology
8. Mans A, Henry, Kejel: Fine needle aspiration of bone tumors
9. Walid, Anil: Cytopathology of soft tissue and bone lesions
10. Krishnan Unni, Carry Y: Dahlin’s bone tumors, 6th edition
11. Richardo, Franco: Tumor and tumor like lesions of bone
144

139. 145