Radiological appearances can provide essential information for accurately diagnosing bone tumors in 95% of cases when clinicians, radiologists, and pathologists share information. Key radiological features include the tumor's location in the bone, characteristics of the lesion such as matrix mineralization patterns, effects on the bone cortex, and surrounding soft tissue involvement. A multidisciplinary approach utilizing clinical presentation, radiological findings, histopathological examination, and increasingly molecular analysis is necessary to establish a definitive diagnosis and appropriate treatment plan for bone lesions.

1. RADIOLOGICAL APPEARANCES
INDICATING PATHOLOGICAL
CHANGES IN BONE TUMORS
DR.ARGHA BARUAH

2. If the clinician , radiologist & pathologist share information,
an accurate diagnosis is possible in at least 95 % of cases of
bone tumors.
Pathologist who attempts to diagnose a neoplasm of
bone without knowledge of clinical features & radiographic
findings is
AT A DISTINCT DISADVANTAGE.

3. There are various individual aspects to be
taken into account so that question of
diagnosis & treatment can only be solved by
closest interdisciplinary co operation
Strategy for Diagnosis of Bone Neoplasms
Proved by experience – as the best way
to avoid clinical disasters.

6. Clinical aspects of diagnosis
• Symptoms of bone tumors are non specific
Pain , Swelling, Pathological fracture
Generally, benign non-growing lesions tend to be asymptomatic and
represent incidental findings.

7. Following clinical symptoms are worth remembering
since they may help in the differential diagnosis:
Osteoid osteoma Small lesion, but highly irritative to
adjacent tissues and typically causes intense night pain
relieved by non-steroidal anti inflammatory drugs.
.

8. Enchondroma vs. chondrosarcoma, grade 1
• Histologically, the distinction between a grade 1
chondrosarcoma and an enchondroma is extremely difficult,
• Histologic features overlap considerably.
• Low-grade chondrosarcoma is a growing tumor and, therefore,
presents with pain.
• Enchondromas tend to be asymptomatic, unless associated
with a pathologic fracture.

9. Metastatic cancers –remember!
By far more common than primary bone tumors
characterized by the following features
• Predominant occurrence : adults > 40 years of age
• Children in the first decade of life.
• Multi focality and predilection for the hematopoietic
marrow
• Sites in the axial skeleton and proximal long bones.
Metastases to long bones distal to the elbows and
knees are unusual.

10. Radiographic appearance of the metastatic tumors can be
- Purely lytic (kidney, lung, colon, and melanoma)
- Purely blastic (prostate and breast carcinoma)
- Mixed lytic and blastic (most common appearance)

13. Primary bone tumors are characterized by:
• Predominant occurrence in the first 3 decades of life,
during the ages of the greatest skeletal growth activity
• The commonest sites for many primary tumors, both
benign and malignant, are in the distal femur and
proximal tibia, the bones with the highest growth
rate.

14. Radiological aspects of diagnosis
PLAIN RADIOGRAPH is usually the first
imaging technique for a suspected bone lesion
• Inexpensive
• Easily obtainable
• Best for assessment of general radiological
features of the tumor.

15. COMPUTER TOMOGRAPHY is a method of choice when
plain film assessment is:
- Difficult owing to the nature of the lesion (eg., permeative
pattern of destruction) or anatomic site (eg., sacrum).
- CT is the best technique in
- Assessment of matrix mineralization,
- Cortical detail, and
- Detection of the cystic and fatty lesions.
CT remains a standard imaging procedure for use in well-selected
clinical situations. Perhaps the best indication for CT is for smaller
lesions that involve cortical structures of bone or spine .

16. MRI is a method of choice for local staging. It is
superior to CT in the definition of
Medullary and Extracortical spread and of the
relationship of the tumour to critical neurovascular
structures.
Remember that the MRI appearances of the majority of bone
tumors are totally non-specific.
You need to examine plain films or CT films to define a
neoplasm.

17. BONE SCINTIGRAPHY is a highly sensitive but
relatively non-specific technique.
Main role is in detection of suspected metastases in the
whole skeleton.
It may also be helpful in the detection of osteoid
osteomas ("double density sign" is present in about
50% of cases and is highly suggestive of this tumor).

20. Osteolytic lesion of bone:

21. A L T - M C P S
• Age
• Location
• Transitional
zone
• Matrix
• Cortex
• Periosteal
reaction
• Soft tissue
swelling

22. According to the age:

24. SITE OF LONG BONE INVOLVEMENT

25. DIAPHYSEAL
• Ewing sarcoma
• Fibrous dysplasia
• Adamantinoma
• Langerhans cell
histiocytosis
• Lymphoma
• Osteoid osteoma
METAPHYSEAL
• Osteosarcoma
• Nonossifying fibroma
• Osteochondroma
• Aneurysmal bone cyst
• Osteomyelitis
• Central Enchondroma
• Chondrosarcoma
• Solitary bone cyst
• Osteomyelitis
EPIPHYSEAL
• Giant cell tumor
• Chondroblastoma
• Osteomyelitis
• Degenerative cyst
• Pigmented villo
nodular synovitis

26. SKELETAL LOCATION

29. Location:
Centric in long bone:
SBC, eosinophilic granuloma, fibrous dysplasia,
ABC and enchondroma are lesions that are
located centrally within long bones.
Eccentric in long bone:
Osteosarcoma, NOF, chondroblastoma,, GCT
and osteoblastoma are located eccentrically in
long bones.

30. Zone of transition:
In order to classify osteolytic lesions as well-defined or ill-
defined, we need to look at the zone of transition
between the lesion and the adjacent normal bone.
Wide zone of transition: An ill-defined border with a
broad zone of transition is a sign of aggressive growth
Small zone of transition:A small zone of transition results
in a sharp, well-defined border and is a sign of slow
growth.

37. PATTERNS OF MATRIX MINERALIZATION
Mineralization patterns (calcification or ossification)
are helpful in identification of bone producing and
cartilage producing tumors.

39. Matrix
“Cloud” like Ossific densities
in Bone = Osteosarcoma

40. Chondroid:
Radiologically, it is usually easier
to recognize cartilage as opposed to
osteoid by the presence of focal
stippled or flocculent densities, or
in lobulated areas as rings or arcs
of calcifications. They are best
demonstrated by CT.

41. Wide Zone of
Transition and
Broken Cortex
could be signs of
Aggressiveness /
Malignancy
Cortex:
Intact
or
Broken

42. TYPES OF PERIOSTEAL REACTION
The periosteum responds to traumatic stimuli or
pressure from an underlying growing tumor by
depositing new bone.
The radiographic appearances of this response reflect
the degree of aggressiveness of the tumor.

47. Soft Tissue
Enormous soft tissue seen in Ewing’s Sarcoma

49. WHO CLASSIFICATION OF BONE
TUMORS
CARTILAGE TUMOURS
Osteochondroma
Chondroma
 Enchondroma
 Periosteal chondroma
 Multiple chondromatosis
Chondroblastoma
Chondromyxoid fibroma
Chondrosarcoma
 Central, primary, and secondary
 Peripheral
 Dedifferentiated
 Mesenchymal
 Clear cell
OSTEOGENIC TUMOURS
Osteoid osteoma
Osteoblastoma
Osteosarcoma
 Conventional
- chondroblastic
- fibroblastic
- osteoblastic
 Telangiectatic
 Small cell
 Low grade central
 Secondary
 Parosteal
 Periosteal
 High grade surface

50. FIBROGENIC TUMOURS
 Desmoplastic fibroma
 Fibrosarcoma
FIBROHISTIOCYTIC TUMOURS
 Benign fibrous histiocytoma
 Malignant fibrous histiocytoma
EWING SARCOMA/ PNET
 Ewing sarcoma
HAEMATOPOIETIC TUMOURS
 Plasma cell myeloma
 Malignant lymphoma, NOS
GIANT CELL TUMOUR
 Giant cell tumour
 Malignancy in giant cell tumour
NOTOCHORDAL TUMOURS
 Chordoma
VASCULAR TUMOURS
 Haemangioma
 Angiosarcoma
NEURAL TUMOURS
 Neurilemmoma
SMOOTH MUSCLE TUMOURS
• Leiomyoma
• Leiomyosarcoma
LIPOGENIC TUMOURS
• Lipoma
• Liposarcoma
MISCELLANEOUS TUMOURS
• Adamantinoma
• Metastatic malignancy
MISCELLANEOUS LESIONS
• Aneurysmal bone cyst
• Simple cyst
• Fibrous dysplasia
• Osteofibrous dysplasia
• Langerhans cell histiocytosis
• Erdheim-Chester disease
• Chest wall hamartoma
JOINT LESIONS
• Synovial chondromatosis

51. TNM staging
Primary tumour (T)
 TX: primary tumour cannot be assessed
 T0: no evidence of primary tumour
 T1: tumour </= 8 cm in greatest dimension
 T2: tumour > 8 cm in greatest dimension
 T3: discontinuous tumours in the primary bone site
Regional lymph nodes (N)
 NX: regional lymph nodes cannot be assessed
 N0: no regional lymph node metastasis
 N1: regional lymph node metastasis
Distant metastasis (M)
 MX: distant metastasis cannot be assessed
 M0: no distant metastasis
 M1: distant metastasis
 M1a: lung
 M1b: other distant sites

52. The characteristic feature is a
projection of the cortex in
continuity with the underlying
bone.
Irregular calcification is often seen.
Excessive cartilage type flocculent
calcification should raise the
suspicion of malignant
transformation.

54. Chondromyxoid fibroma
• Oval, eccentric, lytic
metaphyseal lesion with
long axis parellel to bone.
• Sharply defined, sclerotic,
scalloped borders.
• May extend to diaphyseal
region.

55. Gross
• Firm, gray white lobulated
mass, sharply demarcated &
eccentrically located.
• Periosteum is intact.
• Semi solid myxoid areas may
be seen.
• Chondroid foci usually not
seen grossly.

57. Enchondroma:

60. Gross
• Soft, gelatinous, red tan
tumor with flecks of
chalky calcification.
• Hemorrhage and cystic
change can be present.

63. Chondrosarcoma:
This case, which likely arose from an osteochondroma, shows the charactristic ' rings and
arcs" pattern of calcification.

64. Have translucent, blue-grey/white colour corresponding to presence of hyaline cartilage.
lobular growth pattern is a consistent finding.
Zones of myxoid/ mucoid material & cystic areas +/-.

67. Osteoid Osteoma:
• Well demarcated lytic
lesion (nidus) surrounded
by a distinct zone of
sclerosis.
• A zone of central opacity
that represents more
sclerotic portion of the
nidus surrounded by a
lucent halo may be
present within the nidus.

68. Gross
• Nidus tissue- Distinct
oval or round, reddish
area that can be easily
separated from its bed.
Vary in consistency from
soft friable to densely
sclerotic.
• Nidus is usually
surrounded by large zone
of dense sclerotic bone.

69. Small cortical based, red, gritty/ granular round, sharply circumscribed lesion
surrounded by ivory white sclerotic bone
Nidus < 1.5 cm (any larger size arbitrarily considered to be an osteoblastoma)

71. Osteoblastoma

72. OSTEOBLASTOMA
• Rare benign tumor with nidus > 1.5cms in
diameter & differs from osteoid osteoma by
1) Has a higher growth potential (>2cms.).
2) Lacks nocturnal pain.
3) Pain is not relieved by aspirin.
4) Peripheral sclerosis may be minimal or
absent.

73. GROSS:
Size: 2-15 cm
Extremely vascular red-brown color with
gritty/ sandpaper consistency
Has pushing borders

78. OSTEOSARCOMA
Is a primary intramedullary high grade
malignant tumour in which the
neoplastic cells produce osteoid
Involve metaphysis(91%),
diaphysis(9%)
C/F: pain, palpable mass+/-, reduced
range of motion, warmth, edema,
telenectasias & bruit on ascultation
LAB: raised S. Alk.phos & LDH

79. GROSS

81. MICROSCOPY
Frequently referred to as a "spindle cell“ tumour
Tends to be highly anaplastic & pleomorphic
Tumour cells may be: epithelioid, plasmacytoid, fusiform,
ovoid, small round cells, clear cells, mono- or
multinucleated giant cells, or, spindle cells.
Usually show complex mixtures of two or more of cell
types.
ACCURATE IDENTIFICATION OF OSTEOID

82. OSTEOID
Dense, pink, amorphous, intercellular material, somewhat refractile
Based on thickness:
1. Thinnest – filigree osteoid
2. Osseous matrix with predisposition for appositional deposit on pre-
existing bone trabeculae – scaffolding
3. Grow in angiocentric fashion basket-weave/ cording pattern to tumor
4. Thin tubular anastomosing microtrabeculae which may be basophilic &
vaguely reminiscent of appearance of fungal hyphae/ laid in fish-net
appearance

83. 1. unmineralized osteiod 2. filigree 3. flat
4. basket-weave 5. scaffolding 6. fungal hyphae

86. Telangiectatic Osteosarcoma

88. Periosteal Osteosarcoma:
Upper shaft of tibia shows a well demarcated tumour arising from cortical surface of the
bone. Fluffy calcifications are present.
Proximal Femur-broad based, mushroom-like, large surface tumour with a thickened ossified
area blending in with cortex. Covering this, is a large soft tissue component with 2 layers of
tissue: One is whitish-cartilaginous and the other is tan-yellow.

89. Cartilagenous component predominates.
Matrix may be myxoid.
Bony spicule shows elongated vascular cores
surrounded by calcified/ ossoeus/ chondro-
osseous matrix which is further surrounded
by a non- calcified cartilagenous growth
Periphery of tumor shows fascicles of
spindly cells

91. ‘Soap bubble
appearance’- due to
marked trabeculation
and marginal sclerosis.

92. Gross
• Soft , friable, fleshy and
red brown.
• Well demarcated and
usually extends to the
articular cartilage, but it
is unlikely to be invaded
• Eccentrically placed

94. Ewing’s Sarcoma

101. Gross
• Cystic cavity filled
with a clear or
yellowish fluid.
• Wall- composed of
paper thin tan yellow
fibrous tissue with
multiple bony ridges.
• Focal hemosiderin
deposition is seen.

102. Microscopic examination showed
bland fibrous tissue with sparse
inflammatory infiltrate,
hemosiderin-laden macrofages,
and occasional osteoclast-like
multinucleated giant cells.

104. Gross
• Spongy, multilocular cystic
lesion filled with blood (
size varies from 1 mm-
several cms.).
• Small amount of spongy red
brown soft tissue or thin
membranous septa.
• Borders- Irregular,
lobulated, sharply
demarcated.

116. TO CONCLUDE…..
• The diagnostic triangle
recommended by Jaffe –
surgeon ,radiologist, &
pathologist sharing their
points of view on a bone
lesion to arrive at a
rational diagnosis is still
valid.
• The advent of newer
molecular techniques has
expanded this diagnostic
triangle into a diagnostic
quadrangle.
DIAGNOSIS
CLINICAL
PRESENTATION
RADIOLOGIC
FEATURES
MOLECULAR
DATA
MICROSCOPIC
FEATURES

117. References:
1. WHO Classification of Tumors- Pathology &
Genetics of Tumors of Soft Tissue & Bone,
2013.
2. Rosai & Ackerman’s Surgical Pathology 11TH
EDITION
3. Radiopaedia.org