mainly discussion on bone forming tumors and cartillage forming benign tumors of bone , priority given to imaging

1. BENIGN BONE TUMOURS
Presenter :Dr.Arif khan S
Moderator: Dr.Gururaj Sharma

2. BENIGN BONE TUMOURS
• CLASSIFICATION:
• BONE FORMING
Eg; osteoid osteoma, osteoblastoma, enostosis (bone island), osteopoikilosis
Osteoma,
• CARTILLAGE FORMING
Eg; enchondroma , enchondromatosis (Ollier disease),,
Osteochondroma, chondroblastoma
FIBROUS BONE LESIONS
Eg; fibrous dysplasia, ossifying fibroma
• Miscellaneous
Simple bone cyst; Aneurysmal Bone cyst;

3. IMAGING
• the role of imaging in the management of a patient with a suspected bone
tumour can be broadly
subdivided as follows;
• 1. detection
• 2. diagnosis
• 3. surgical staging
• 4. follow-up

4. CARTILLAGE FORMING BENIGN TUMORS

5. ENCHONDROMA
• common benign medullary cartilaginous neoplasm
• usually found in children or young adults which can lead to pathological
fractures or undergo malignant degeneration.
• 3-10 % of all bone tumours and 12-24 % of benign bone tumours
• Enchondromas are most frequently diagnosed in childhood to early
adulthood with a peak incidence of 10-30 years.
• complicated by a pathological fracture or malignant transformation into a
low grade chondrosarcoma
• (clinically if an enchondroma is painful in the absence of a fracture, it should
be considered malignant

6. ENCHONDROMA
• Enchondromas arise from rests of growth
plate cartilage/chondrocytes that
subsequently proliferate and slowly enlarge
and are composed of mature hyaline
cartilage.
• they are seen in any bone formed from
cartilage.
• Two syndromes are associated with multiple
enchondromas:
Ollier disease
Maffucci syndrome.
• small tubular bones of the hands and feet :
50%
• large tubular bones e.g. femur, tibia,
humerus

7. ENCHONDROMA
• Rarely an enchondroma may extend through the cortex and demonstrate a
exophytic growth pattern. This is known as an enchondroma protuberans, and
may either be seen sporadically or as part of Ollier disease.
• Almost all enchondromas are located in the medullary cavity of tubular bones.
The typical distribution is :
D/ds:
• bone infarct , chondrosarcoma, intraosseous ganglion
• other benign lytic bone lesions,
• metastases
• granulomatous disease : sarcoidosis, tuberculosis

8. IMAGING
• X-ray & CT
Typically enchondromas are small 1 - 2cm lytic lesions with non-
aggressive features.
narrow zone of transition
sharply defined scalloped margins : may have mild endosteal
scalloping
expansion of the overlying cortex may be present but there
should not be cortical breakthrough unless fractured
chondroid calcifications may be present : rings and arcs
calcification
no periosteal reaction
no soft tissue mass.
• The majority of enchondromas more frequently arise in the
metaphyseal region,.
A cartilaginous lesion in an epiphysis is more likely to be a
chondrosarcoma .

9. IMAGES

11. IMAGING
• MRI
• MRI is useful in evaluating for soft tissue extension and for confirming the diagnosis.
• Enchondromas appear as well circumscribed somewhat lobulated masses replacing
marrow.
• T1
intermediate to low signal
• T1 C+ (Gd)
enhancement is variable, and may be seen both peripherally or of translesional septae.
Similar pattern of enhancement may be seen in chondrosarcomas.
• T2
typically of background intense high signal
they can be focal regions of signal drop out where calcification present
no bone marrow or soft tissue oedema

12. IMAGES
• T1 T2 STIR
• Hypointense Hyperintense

13. • Ollier disease also known as
enchondromatosis, is a non-
hereditary, sporadic, skeletal
disorder characterised by
multiple enchondromas that
are principally located in the
metaphyseal regions.
• Plain films show multiple
enchondromas. Larger lesions
can show cartilage
calcification in a typical rings
and arcs pattern.
• Imaging characterestics are of
same as ENCHONDROMAS

14. MAFUCCI’S SYNDROME
• Maffucci syndrome is a congenital non hereditary mesodermal dysplasia
characterised by multiple enchondromas with soft-tissue cavernous
haemangiomas.
• Imaging findings are
multiple enchondromas seen associated with soft tissue swelling and phleboliths.
• Enchondromas degenerate into chondrosarcomas in 15-51% 3 of cases and
soft-tissue haemangiomas to vascular sarcomas in 3-5%.

15. OLLIER’S
DISEASE

MAFFUCI’S
DISEASE


16. CHONDROBLASTOMA
• rare benign cartilaginous neoplasms
• less than 1% of all primary bone tumours, occurring predominantly in young
patients (< 20 years of age). There is a male predilection.
• Pathologically composed of chondroblasts, chondroid matrix, cartilage with
occasional giant multi-nucleated cells.* with surrounding chondroblasts.
• Aneurysmal bone cysts can be seen secondarily to underlying
chondroblastoma.

17. • epiphysis of a long bone (70%
occurring in the humerus (most
frequent), femur and tibia, ~ 10%
are found in the hands and feet)

18. IMAGING
• X-rays
• epiphyseal
• well defined lytic lesions; either smooth or lobulated margins with a thin
sclerotic rim
• Internal calcifications can be seen in up to 40-60% of cases
• They range in size from 1-10cm, with most being 3-4cm at diagnosis
• CT
• better delineation of the relationship to the growth plate and articular surface
• Solid periosteal reaction (seen in up to 50% of cases) and internal calcification
(calcified matrix seen in ~ 1/2 of cases) and cortical breach are also more
easily appreciated.
• Endosteal scalloping may be seen

19. IMAGE

20. IMAGING
• MRI
• ideal for the evaluation of transphyseal or transcortical extension.
• Demonstrating associated surrounding bone marrow oedema.
• These lesions have signal typical of cartilage:
T1 - lesion itself is of low to intermediate signal
T2 / STIR - lesion is of intermediate to high signal
• Fluid-fluid levels may occasionally be seen .

21. IMAGE
• T1 T2 STIR

22. OSTEOCHONDROMA
• Developmental anomalies rather than tumors.
• They are usually sporadic, but can be part of:
Hereditary multiple exostoses (HME) - also known as diaphyseal aclasis
Trevor disease
An osteochondroma can be either sessile or pedunculated, and is seen in the
metaphyseal region typically projecting away from the epiphysis.

23. • They most commonly arise from
appendicular skeleton, especially around
the knee 3.
• lower limb - 50% of all cases femur
(especially distal) - most common : 30%
• tibia (especially proximal) - 15-20%
• less common locations - feet, scapula
• upper limb
• humerus - 10-20%
• less common locations - hands, pelvis
• spine - the posterior elements of spine are
an uncommon, but not rare, site for these
tumours

24. • Pathologically Osteochondromas are
essentially a part of the growth plate.
• Separates and continues growing
independently, without an associated
epiphysis
• The medullary cavity is continuous with
the parent bone, and they are
capped by hyaline cartilage
• D/ds
• hands - bizarre parosteal
osteochondromatous proliferation
(BPOP)
• humerus - supracondylar spur : projects
towards the elbow joint
• malunited fracture

25. • X-ray findings.
• An osteochondroma can be either sessile or pedunculated, and is seen in
the metaphyseal region typically projecting away from the epiphysis.
• There is often associated broadening of the metaphysis from which it arises
• The cartilage cap is variable in appearance. It may be thin and difficult to
identify, or thick with rings and arcs calcification and irregular subchondral
bone.
• CT
• Better visualisation of medullary continuity and the cartilage cap.

27. • MRI
• MRI is best at assessing cartilage thickness
(and thus assessing for malignant
transformation), presence of oedema in
bone or adjacent soft tissues and
visualising neurovascular structures in the
vicinity.
• The cartilage cap of osteochondromas
appears the same as cartilage elsewhere,
with intermediate to low signal on T1 and
high signal on T2 and STIR weighted
images.
• A cartilage cap of over 1.5cm in thickness
is suspicious for malignant degeneration.

28. T1 T2 STIR

29. • Bone scan
During growth osteochondromas demonstrate increased uptake, but with
time they become no more active than normal bone. Presence of increased
activity in adulthood should raise the possibility of a complication (fracture,
malignancy).

30. CHONDROMYXOID FIBROMA
• Extremely rare, benign cartilaginous neoplasms that account for < 1% of all
bone tumours.
• Second and third decades, with approximately 75% of cases occurring before
the age of 30 years.
• Pathologically comprises of a variable combination on chondroid, myxoid, and
fibrous tissue components organised in a pseudolobulated architecture.
• Occasional osteoclast-like giant multinucleated cells are encountered
particularly at the periphery.
• D/ds: aneurysmal bone cyst (ABC), giant cell tumour of bone (GCT), non
ossifying fibroma: younger age group, chondroblastoma: younger age group

32. IMAGING
• X-rays &CT
often seen as a lobulated, eccentric radiolucent lesion
long axis parallel to long axis of long bone
no periosteal reaction (unless a complicating fracture present)
geographic bone destruction: almost 100%
well defined sclerotic margin: 86%
there can be presence of septations (pseudotrabeculation): 57% 2
there can be presence of matrix calcification in small porportion cases: 12.5%1
• Bone Scan – Doughnut sign (non- specific)

33. IMAGES

34. • MRI
• Non specific.
• T1- low signal (hypointense)
• T1 C+ (Gd)
• the majority (~70%) tend to show peripheral nodular enhancement.
• 30% diffuse contrast enhancement and this can be either homogeneous or
heterogeneous .
• T2 - hyperintense

35. IMAGES

37. MISCELLANEOUS TUMORS

38. SIMPLE BONE CYST
• A.k.a Unicameral bone cysts.
• Relatively common Radiolucent bony lesions
• seen in childhood and typically remain asymptomatic.
• 1st and 2nd decades (65% in teenagers), and are more common in males
• frequently found in the metaphysis of long bones, abutting the growth plate.
proximal humerus: most common 50-60%
proximal femur: 30%

39. IMAGING
• X-ray & CT
Sharply demarcated.
Radiolucent lesions.
Periosteal reactions.
Expand the bone with thinning of
the overlying bone.
• Fallen fragment sign: a
dependent bony fragment
within the lesion.
Seen when assosciated fracture is
present.

40. MRI
MR signal characteristics for an uncomplicated lesion include
T1 - low signal
T2 - high signal
Usually there no fluid-fluid levels unless there has been a complication with
haemorrhage.
CT and MRI add little to the diagnosis, but are however helpful in eliminating other
entities that can potentially mimic a simple bone cyst

41. T1 T2

42. ANEURYSMAL BONE CYST (ABC)
• Benign , Expansile
• Primarily seen in children and adolescents (80% l <20yrs of age)
• blood-filled spaces of variable size separated by connective tissue
(trabeculae of bone or osteoid tissue) and osteoclast giant cells
• Not lined by endothelium.
Types
• Primary
• Secondary
(e.g chondroblastoma, fibrous dysplasia, giant cell tumour (GCT), osteosarcoma)

43. • Location
Long bones – tibia & fibula (24%),
femur (13%),
Spine 20-30% (posterior elements).
sacrum
• A variant of ABCs is the giant cell
reparative granuloma.
seen in the tubular bones – hand ,
feet craniofacial skeleton.

44. RADIOGRAPHIC FEATURES
• X ray
sharply defined, expansile osteolytic
lesions, with thin sclerotic margins.
Eccentricity is typical.
But very often missed out due to cortical
thinning due to ballooning.
CT
Demonstrates these findings to a
greater degree, and is also better at
assessing cortical breach and extension
into soft tissues.
Fluid fluid levels (better than MRI)

46. • MRI
Demonstrate Fluid Fluid level in lesion.
To distinguish between Primary and secondary (if solid component Is present.)
The cysts are of variable signal, with surrounding rim of low T1 and T2 signal.
Focal areas of high T1 and T2 signal are also seen presumably representing
areas of blood of variable age.

47. • Bone scan:
• Doughnut sign - increased
uptake peripherally with a
photopenic centre.

48. ADAMANTINOMA
• LONG BONES (tibia exclusively)AND JAW.
• 2nd to 3rd decades as a locally aggressive mass .
• slight male predilection.
• Since it is a low-grade malignancy, it can metastasise to distant locations
including : lung, bone, lymph nodes, pericardium and liver.
• D/ds
• fibrous dysplasia
• osteofibrous dysplasia : has a more ground glass texture on CT

49. • X-rays & CT
Appears as a multi-locular or slightly
expansile osteolytic lesion.
areas of lysis interspersed with areas
of sclerosis
Lesions tend to have an eccentric
epicentre.
lack of periosteal reaction

50. . MRI
• a solitary lobulated focus
• multiple small nodules in one or more foci.
• Separated tumour foci,
defined as foci of high signal intensity on either T2 or T1-weighted contrast-
enhanced images, interspersed with normal-appearing cortical or spongious
bone .
C+(Gd) : tends to show intense and homogeneous static enhancement,
although there is no uniform dynamic enhancement pattern.

51. IMAGES

52. AMELOBLASTOMA
• Ameloblastomas (previously known as an adamantinoma of the jaw) are
benign, locally aggressive tumours that arise from the mandible, or less
commonly from the maxilla.
• They are slow growing and tend to present in the 3rd to 5th decades of life, with
no gender predilection.
• X-rays &CT findings
• It is classically seen as a multilocualted (80%), expansile "soap-bubble" lesion,
with well demarcated borders and no matrix calcification.
• erosion of the adjacent tooth roots can be seen which is highly specific.
• larger it may also erode through cortex into adjacent soft tissues.
• MRI findings
• ameloblastomas demonstrate a mixed solid and cystic pattern, with a thick
irregular wall, often with papillary solid structures projecting into the lesion.
• These components tend to vividly enhance

54. • d/ds
• dentigerous cyst : 20% of ameloblastomas thought to arise from pre-existing
dentigerous cysts
• odontogenic keratocyst (OKC) -unilocular with thin poorly enhancing walls
• odontogenic myxoma - can be almost indistiguishable
• aneurysmal bone cyst (ABC)
• fibrous dysplasia

55. SUMMARY

56. Most common location
FD = Fibrous dysplasia
EG = Eosinophilic Granuloma
NOF = Non Ossifying Fibroma
SBC = Simple Bone Cyst
CMF = Chondromyxoid fibroma
ABC = Aneurysmal bone cyst
HPT = Hyperparathyroidism with Brown tumor
GCT = Giant cell tumour

57. Most primary tumours are seen in patients
less than 30 years of age
In patients greater than 30 years ,
secondary tumours (eg ;brown tumours)
and metastatic deposits are common.

58. COMMON
LOCATIONS OF
LESIONS
FD = Fibrous dysplasia
EG = Eosinophilic Granuloma
NOF = Non Ossifying Fibroma
SBC = Simple Bone Cyst
CMF = Chondromyxoid fibroma
ABC = Aneurysmal bone cyst
HPT = Hyperparathyroidism with Brown tumor
GCT = Giant cell tumour

59. MOST COMMON LOCATIONS
• Aneurysmal Bone Cyst
tibia, femur, fibula, spine, humerus
• Adamantinoma
tibia shaft, mandible
• Chondroblastoma
femur, humerus, tibia, tarsal bone (calc), patella
• Chondromyxoid fibroma
tibia, femur, tarsal bone, phalanx foot, fibula

60. • Enchondroma
phalanges of hands and feet, femur, humerus, metacarpals, rib
• Osteochondroma
femur, humerus, tibia, fibula, pelvis
• Solitary Bone Cyst
proximal humerus, proximal femur, calcaneal bone, iliac bone

61. SPOTTERS