benign bone tumors imaging

1. BENIGN BONE
TUMORS
RIYAZ AHMED S

2.  The pre-biopsy diagnosis of a bone tumour depends upon several
features, including patient age, lesion location and finally the
radiological characteristics

3. Age at Presentation
 Patient age is of huge importance in
suggesting a differential diagnosis of a focal
bone lesion.
 Primary bone tumours are rare below the
age of 5 years

4. LocationEpiphysis
 Only a few lesions are located in the epiphysis, so this
could be an important finding.
 In young patients it is likely to be either a
chondroblastoma or an infection.
 In patients over 20, a giant cell tumor
 In older patients a geode, i.e. degenerative
subchondral bone cyst can ba a differential
Metaphysis
 NOF, SBC, CMF, Osteosarcoma, Chondrosarcoma,
Enchondroma and infections.
Diaphysis
 Ewing's sarcoma, SBC, ABC, Enchondroma, Fibrous
dysplasia and Osteoblastoma.

6. Rate of Growth
 When considering rate of growth, the most important
feature is the lesion margin
 In benign and low-grade malignant neoplasms, this
margin is sharp (GEOGRAPHICAL; Type 1).
 Type 1A has a rim of sclerosis between the lesion and
the host bone
 Type 1B is a very well defined lytic lesion but with no
marginal sclerosis
 Type 1C has a slightly less sharp, nonsclerotic margin
1) NOF
2) ABC
3) ABC

7.  Type 2 is MOTH-EATEN
DESTRUCTION, which represents
the next most aggressive pattern and is
characterised by multiple lucent areas
measuring 2–5 mm in diameter
separated by bone which has yet to be
destroyed .
 Type 3 is PERMEATIVE destruction,
which is the most aggressive pattern
and is composed of multiple
coalescing small ill-defined lesions 1
mm or less in diameter with a zone of
transition of several centimetres
Here there is also a
large circumferential
extra osseous mass

8. Periosteal Reaction
 Periosteal reaction is of various types with none being pathognomonic of any
particular tumour. Rather, the type helps to indicate the aggressiveness of the
lesion.
 A thick, well-formed SOLID PERIOSTEAL
REACTION indicates a slow rate of growth but
not necessarily a benign tumour, since it may be
seen with chondrosarcoma.
Laminated periosteal reaction (indicates
subperiosteal extension of tumour, infection
or haematoma.
 Lesions demonstrating periodic growth may
show a multi-laminated pattern
osteoid osteoma
ABC. Note also the
Codman’s triangle
(arrowhead).

9.  VERTICAL (SUNBURST SPICULATION OR ‘HAIR-ON-
END’) types of periosteal reaction are seen with the
most aggressive tumours such as osteosarcoma
and Ewing’s sarcoma.
Acute osteomyelitis.
Lesions demonstrating periodic
growth may show a MULTI-
LAMINATED PATTERN
Osteosarcoma

10.  A Codman's triangle refers to an elevation of the periosteum away from the
cortex, forming an angle where the elevated periosteum and bone come
together.
 Fibrous dysplasia, Enchondroma, NOF and SBC will not present with a
periosteal reaction unless there is a fracture.

11. Matrix Mineralisation
 The matrix of a tumour represents the extracellular material produced by the tumour
cells within which the cells lie
 Chondral calcifications are typically linear, curvilinear, ring-like, punctate or
nodular .
 Osseous mineralisation is cloudlike and poorly defined
 Diffuse matrix mineralisation in benign fibrous tumours produces the
characteristic ‘ground-glass’ appearance seen most commonly in fibrous dysplasia
Chondrosarcoma,
typical punctate
chondral
calcification
Osteoblastic osteosarcoma
-typical ‘cloud-like’ osseous
mineralisation
Fibrous dysplasia
showing typical
‘ground-glass’
mineralisation

12.  Benign bone tumours are currently classified according to the 2002
World Health Organisation system based on their cell of origin

13. CARTILAGE TUMOURS
Osteochondroma
 Most common benign tumor; 2 to 60 years, but highest e is in the second
decade, with a M:F of 1.4–3.6 : 1. typically metaphyseal
 Long bones are commonly affected, especially around the knee
(~40%),
 The commonest -distal femur, proximal humerus, proximal tibia and
proximal femur. The commonest flat bones affected are the ilium
and scapula.
 Lesions may be classified as either
 pedunculated, when they have a thin stalk that typically points away
from the adjacent joint, or
 sessile when they arise from a broad base..

14.  Diaphyseal aclasis (hereditary multiple exostoses, HME) constitutes
an uncommon autosomal dominant disorder in which the exostoses
may be larger than the solitary variety and may lead to shortening
or deformity of the affected limbs.
 The metaphyses in this condition are also typically widened and
dysplastic
Osteochondromas present with mechanical problems
such as an enlarging mass, pressure on adjoining
structures

15.  Continuity between the medullary cavity of the
lesion and that of the underlying bone is essential
for the diagnosis and is best demonstrated on
either CT or MRI
 The cartilage cap is optimally demonstrated on
axial proton density-weighted (PDW) or T2W MRI,
when the hyperintense cartilage contrasts well
against the adjacent iso-/hypointense muscle
and it should not exceed 2-cm thickness in adults.
 The cartilage cap can also be visualised and
measured on ultrasound where it appears
hypoechoic in contrast to the brightly reflective
bone surfaces.

16. (En)Chondroma
 It is an intramedullary neoplasm comprising lobules of benign
hyaline cartilage and is the 2nd MC benign chondral lesion
 20-40 yrs; M:F --- 1:1
 Meta / diaphyseal
 Tubular bones of the hands and feet – MC in proximal phalanges
(40–50%), followed by the metacarpals (15–30%) and middle
phalanges (20–30%).
 Well-circumscribed, central , lobular or oval lytic lesions, which may
expand the cortex with size ranging from 10 to 50 mm with
chondral-type mineralisation
mildly expansile lesion with typical
chondral matrix mineralisation

17.  ENCHONDROMA PROTUBERANS’ -an
eccentrically placed enchondroma with
an associated extraosseous component
which is usually covered by a thin shell of
intact cortical bone

18.  MRI FEATURES
 Intermediate SI in T1 and hyper intensity in T2/STIR without
surrounding reactive oedema
 Matrix mineralisation manifests as punctate areas of signal void.

19. Less Common Varieties of
Chondroma
 Periosteal Chondroma-These are rare lesions
affecting children and young adults and are
located in the metaphyses of tubular bones,
most commonly the proximal humerus
followed by the femur and tibia.
surface lesion with a thin surrounding calcified rim
(arrows) and extension into the adjacent medullary
cavity

20. Enchondromatosis (Ollier’s
Disease).
 Rare disease.
 In addition to multiple enchondromas,
flame-like rests of cartilage in the
metaphyses impede bone growth and
may result in bowing, angulation and
bone enlargement .
 Malignant change is reported in 5–30%
of cases
Multiple enchondromas, with expansion of the
proximal right femur and deformity consistent
with Ollier’s disease. A lesion is also seen on the left
side

21. Enchondromatosis with Haemangiomas
(Maffucci’s Syndrome).
 This rare disorder combines multiple enchondromas and soft-tissue
haemangiomas (occasionally lymphangiomas).
 Radiographically, the presence of phleboliths differentiates the
disorder from ollier’s disease.
 Haemangiomas are well demonstrated by mri.

22. Chondroblastoma
 classically located eccentrically in the
epiphysis
 50% around knee joint
 M:F --- 2.7:1
 5-25 yrs
 usually spherical or lobular with a fine
sclerotic margin, measuring 1–4 cm in size
 Linear metaphyseal periosteal reaction
With a solid periosteal response

23. Chondroblastoma
 MRI shows intermediate T1W SI with
variable SI on T2W images (Fig. 47-
13C), including hypointensity and
FFLs due to secondary aneurysmal
bone cyst (ABC) change (~15% of
cases).
 Associated marrow and soft-tissue
oedema and reactive joint effusion
are almost invariable
T1 STIR

24. Chondromyxoid Fibroma
 10 and 30 years
 metaphyseal and eccentric within the
medulla, resulting in thinning and
expansion of the cortex.
 The long bones account for 60% of
cases, with 40% arising in the flat bones
(ilium 10%) or small tubular bones of the
hands and feet (17%).
 The upper third of the tibia – MC site.
An eccentric lytic lesion with a sclerotic margin
(arrows) and expansion of the anterior cortex.

25. OSTEOGENIC TUMOURS
Osteoid Osteoma
 This small benign, vascular, osteoblastic tumour is often associated with a
characteristic clinical picture of night pain relieved by aspirin
 20- 30 yrs / M:F 2-3 : 1 / Meta/diaphysis of tibia & femur
 The characteristic feature is the nidus, which may appear lytic, sclerotic or most
commonly of mixed density depending upon the degree of central
mineralisation.
 The nidus measures up to15 mm in diameter and is commonly surrounded by a
region of reactive medullary sclerosis and solid periosteal reaction
 Nidus is either intracortical, medullary (cancellous) or subperiosteal

26.  Vascular groove sign, which is manifest by the presence of
thin, serpentine channels in the thickened bone surrounding the
nidus viz demonstrated in CT
The nidus appears as heterogenously low–
intermediate SI on both T1W and T2W
images and enhancing strongly following IV
contrast .
In addition to the reactive bony changes,
oedema-like marrow and soft-tissue SI is almost
invariably seen adjacent to the nidus
STIR
T2
The natural history of OO is spontaneous
resolution, which may be promoted with
the use of nonsteroidal anti-inflammatory
drugs

27. Osteoblastoma
 Histologically similar to OO and is differentiated primarily by its size(>
1.5 cm)
 More aggressive growth pattern with potential for extraosseous
extension, and does not resolve spontaneously
 pain is not usually acute or severe and is rarely relieved by aspirin.
 humerus is the commonest location and arises in the medullary
cavity.

28. Osteoblastoma
 predominantly
lytic, measuring
over 2 cm
 occult
calcification,
which can be
punctate, nodular
or generalised
 Like OO,
scintigraphy is
always positive
large mixed
lytic-sclerotic
lesion
CT shows the
oval, mineralised
lesion
STIR hypo
intense tumour
(arrows) with
extensive
reactive
oedema-like
marrow

29. FIBROGENIC TUMOURS
Desmoplastic Fibroma
 rare, locally aggressive
 10-30yrs; MC in metaphysis of femur,
humerus, tibia and radius
 Many are large at presentation (over
5 cm in diameter) and two patterns
are seen:
 an ill-defined moth-eaten or
permeative lesion and
 an expanding, trabeculated lesion

30. FIBROHISTIOCYTIC TUMOURS
 Fibrous cortical defect, non-
ossifying fibroma and benign fibrous
histiocytoma all share identical histological
appearances but are differentiated by their
clinical and radiological features.
 Fibrous cortical defect (FCD)
 Is most common in the distal femoral and proximal
tibial metaphyses
 as an incidental finding,
 appearing as a cortically based lytic lesion
commonly with a thin sclerotic margin.
 The lesion typically consolidates/fades with time.

31. Non-ossifying fibroma
 is commonly identified incidentally, or may present with
pathological fracture when large enough.
 the tibia and distal end of the femur; mean age 20yrs
 Meta or diametaphyseal
 Can be associated with neurofibromatosis
 Jaffe–Campanacci syndrome consists of multiple (usually
unilateral) NOFs with café-au-lait spots but no other stigmata of
neurofibromatosis

32.  Characteristically INTRACORTICAL with the lesion
usually enlarging into the medullary cavity
 When NOF arises in a slim bone such as the
fibula, it crosses the shaft readily and its
characteristic intracortical origin is less obvious
 The tumour is oval with its long axis in the line of
the bone
 On MRI, shows low–intermediate SI on T1W and
PDW images and enhances following
administration of intravenous gadolinium contrast
medium.
 On T2W images, approximately 80% are
hypointense, but with marginal or septal
hyperintensity

33. Benign fibrous histiocytoma
 Uncommon lesion /older age group (30 -50
yrs) / M:F 1:1
 Resembles a giant cell tumour,
 Occurring in an eccentric subarticular
location, but with a well-defined sclerotic
margin indicating slower growth.
 About one-third occur on either side of the
knee.
 MRI features are also similar to GCT.

34. Giant Cell Tumour
 18-45 ys/ M:F 2:3
 subarticular or subcortical region
 the knee (distal femur/proximal tibia—55%)
 Distal radius (10%)
 proximal humerus (6%)
 aggressive benign neoplasm
 malignant change in GCT is recognised, being either primary or
secondary
 associated with hyperparathyroidism.

35.  GCT is classically a subarticular, eccentric, lytic lesion
with a geographic, non-sclerotic margin
 usually measures 5–7 cm in size. Apparent
trabeculation and cortical expansion are common
features and periosteal reaction is seen
 On MRI,
 Iso- or hypointense on T1W
 heterogeneous hyperintensity on STIR.
 Areas of hyperintensity on T1W indicate the presence of
subacute haemorrhage.
 Profound hypointensity on T2W images in solid areas of
the tumour is due to the deposition of haemosiderin
from chronic recurrent haemorrhage
 FFLs indicate the presence of secondary ABC change
internal
trabeculation.

36. VASCULAR TUMOURS
 HAEMANGIOMA
 congenital vascular malformations
 classified histologically as capillary, cavernous,
arteriovenous or venous.
 Osseous capillary haemangiomas most commonly
affect the vertebral body, whereas osseous
cavernous haemangiomas affect the skull vault.
 Bone expansion and extraosseous extension are present.
 CT demonstrates the thickened trabeculae as dense
‘dots’ within a fatty matrix .(polka dot)
 On MRI, long and flat bone haemangiomas are typically
of intermediate SI on T1W and hyperintense on T2W,

37. GLOMUS TUMOR
 Rare, benign vascular tumor affecting soft tissue more than bones.
 Clinically they are tender.
 Pressure erosion of terminal phalanx, particularily of subungual
portion.
 Extremely sharp margin associated with well marked sclerotic rim.
 Angio – richly vascular
 Classical triad of pain, tenderness and sensitivity to cold establishes
the cinical diagnosis.
discrete soft tissue mass caused pressure erosion on
the radial side of terminal phalanx

38. LIPOGENIC TUMOURS
 INTRAOSSEOUS LIPOMA
 arises in the medulla and produces expansion
 Most affect the lower limb, with a predilection for
the calcaneus and femur.
 CT and MRI establish the diagnosis by
demonstrating the fatty nature of the matrix.
 PAROSTEAL LIPOMA
 MC in proximal radius, where it may cause
posterior interosseous nerve palsy.
 It may result in pressure erosion of the bone and
the formation of circumferential juxtacortical new
bone.

39. MISCELLANEOUS LESIONS
 ANEURYSMAL BONE CYST
 5- 20 yrs / M:F 1:1
 the long bones (>50% of cases) and spine (20% of cases) are
most common
 Secondary ABC change can develop in a variety of benign or
malignant lesions, including non-ossifying fibroma,
chondroblastoma, giant cell tumour, fibrous dysplasia,
osteoblastoma and osteosarcoma.
 The classical lesion is a purely lytic, expansile intramedullary
lesion in the metaphysis of a long bone extending to the
growth plate, which may be centrally or, more commonly
eccentrically placed.
 A thin ‘egg-shell’covering of expanded cortex is often
identified,
 Apparent trabeculation &marginal periosteal reaction.

40. Aneurysmal Bone Cyst
 It shows heterogeneous intermediate SI on T1 and a thin
sclerotic margin with internal hypointense internal septa
may be seen, which may enhance following
administration of gadolinium contrast medium.
 T2 or PDW images almost invariably demonstrate
multiple FFLs which commonly fill the whole of the lesion.
 The absence of fluid levels may indicate a ‘solid’ variant
of ABC

41. Simple Bone Cyst (Unicameral
Bone Cyst)
 5 – 15 yrs / M:F - 2.5:1
 Presentation with pathological fracture is classical
 The proximal humerus is by far the commonest site followed by the
proximal femur
 Initially in proximal metaphysis & progress toward the diaphysis
 With skeletal growth, eventually reaching the middiaphysis.
 Usually lies centrally in the shaft, expanding the bone symmetrically
and thinning the cortex.
 Typically 6–8 cm in size.
 Periosteal reaction is not seen without fracture, which may result in
a fragment of cortex penetrating the cyst lining, resulting in the
fallen fragment sign
 MRI demonstrates the fluid content of the lesion

42. Fibrous Dysplasia
 may either be monostotic or polyostotic
 The commonest sites of monostotic FD are the ribs (28%), proximal
femur (23%) and craniofacial bones (20%).
 Meta diphyseal.
 Polyostotic FD may range from the involvement of two bones to more
than 75% of the skeleton. Approximately 30–50% of patients with
polyostotic disease have café au lait spots.
 FD may be associated with a variety of syndromes.
 McCune–Albright’s syndrome consists of polyostotic FD (typically
unilateral), ipsilateral café au lait spots and endocrine disturbance, most
commonly precocious puberty in girls.
 Mazabraud’s syndrome consists of FD (most commonly polyostotic)
and soft-tissue myxomata

43. Fibrous Dysplasia
 geographic lesion that may cause bone
expansion and deformity with diffuse
ground-glass matrix mineralisation
 A thick sclerotic margin (‘RIND’
SIGN) is characteristic.
 Purely lytic lesions are also seen,
indicating extensive cystic
degeneration.
 Periosteal reaction is absent
 Varus deformity of the proximal femur
(‘shepherd’s crook’ deformity) is a
characteristic late finding.

44. Fibrous Dysplasia
 Skeletal scintigraphy is the best
technique for identifying polyostotic
disease although whole-body MRI may
also be used.
 CT demonstrates the ground-glass
matrix.
‘ground-glass’ matrix (arrows),
through which there has been a pathological
fracture.

45.  On MRI, lesions are usually isointense on T1W but may
show areas of mild hyperintensity due to haemorrhage.
 Lesions may be of intermediate SI or hyperintense on T2W,
depending upon whether the tumour is mainly fibrous or
has undergone cystic change.
 Internal septa and FFLs may also be seen.
 Following IV contrast , either uniform or septal
enhancement is seen.
T2W FSE MRI shows the fibrous component of the tumour to have
intermediate SI (arrows), while the haemorrhagic component is
hyperintense.
Note also the FFLs (arrowheads).

46. Osteofibrous Dysplasia
 Osteofibrous dysplasia (OFD) is a rare lesion that
histologically resembles fibrous dysplasia and the stroma
of adamantinoma.
 0 – 40 yrs; MC in < 10 yrs
 M:F 1:1
 The tibia is affected in over 90% and MC location is
anterior mid-diaphyseal cortex .
 In early infancy the lesion expands and bows the tibia
with a sclerotic rim.
 After 3 months of age, the lesion is eccentric,intra cortical
, multilocular and may be purely lytic or show ground-
glass matrix mineralisation similar to that of FD.

47. Langerhans Cell Histiocytosis (LCH)
 LCH represents a spectrum of disorders characterised by the
idiopathic proliferation of histiocytes (Langerhans cells), which can
involve virtually any organ and present either as focal/multifocal
lesions or as a multi-organ systemic disease. Three forms of the
disease were classically described:
 Eosinophilic granuloma
 Letterer–Siwe disease
 Hand–Schüller–Christian disease
 Currently, the disorder is classified as being localised (single-system
disease) or disseminated (multi-system disease).

48.  Localised skeletal disease accounts for
approximately 70% of cases of LCH and is classically
seen in children between the ages of 5 and 15 years
who present with focal bone pain.
 most lesions involve the skull, pelvis, spine, mandible
and ribs.
 MC in diaphysis
 Lytic, showing a fairly aggressive pattern of bone
destruction with multi-laminated periosteal response.
 MRI shows a poorly defined lesion with intermediate
T1 signal intensity with marrow and soft tissue edema
changes.
 Whole-body MRI may replace scintigraphy for the
assessment of multifocal disease.
Fat-suppressed T2W FSE MRI showing an
irregular hyperintense lesion (arrows) with
associated periosteal response and soft-
tissue oedema

49. Erdheim–Chester’s Disease
 It is a rare form of histiocytosis
characterised by the medullary infiltration
of foamy, lipid-laden histiocytes.
 It usually presents in adults over the age of
40 years with bone pain most commonly
related to the knees and ankles.
 Radiographs classically demonstrate
bilateral, symmetrical metaphyseal and
diaphyseal medullary sclerosis with sparing
of the epiphyses.

50. THANK YOU