• 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
• Enchondromas arise from rests of growth
plate cartilage/chondrocytes that
subsequently proliferate and slowly enlarge
and are composed of mature hyaline
• they are seen in any bone formed from
• Two syndromes are associated with multiple
• small tubular bones of the hands and feet :
• large tubular bones e.g. femur, tibia,
• 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 :
• bone infarct , chondrosarcoma, intraosseous ganglion
• other benign lytic bone lesions,
• granulomatous disease : sarcoidosis, tuberculosis
• X-ray & CT
Typically enchondromas are small 1 - 2cm lytic lesions with non-
narrow zone of transition
sharply defined scalloped margins : may have mild endosteal
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
no periosteal reaction
no soft tissue mass.
• The majority of enchondromas more frequently arise in the
A cartilaginous lesion in an epiphysis is more likely to be a
• MRI is useful in evaluating for soft tissue extension and for confirming the diagnosis.
• Enchondromas appear as well circumscribed somewhat lobulated masses replacing
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.
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
13. • Ollier disease also known as
enchondromatosis, is a non-
hereditary, sporadic, skeletal
disorder characterised by
multiple enchondromas that
are principally located in the
• 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
• 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%.
• 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
17. • epiphysis of a long bone (70%
occurring in the humerus (most
frequent), femur and tibia, ~ 10%
are found in the hands and feet)
• well defined lytic lesions; either smooth or lobulated margins with a thin
• 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
• 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
• Endosteal scalloping may be seen
• 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 .
• Developmental anomalies rather than tumors.
• They are usually sporadic, but can be part of:
Hereditary multiple exostoses (HME) - also known as diaphyseal aclasis
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
24. • Pathologically Osteochondromas are
essentially a part of the growth plate.
• Separates and continues growing
independently, without an associated
• The medullary cavity is continuous with
the parent bone, and they are
capped by hyaline cartilage
• hands - bizarre parosteal
• 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
• 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
• 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
• A cartilage cap of over 1.5cm in thickness
is suspicious for malignant degeneration.
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,
30. CHONDROMYXOID FIBROMA
• Extremely rare, benign cartilaginous neoplasms that account for < 1% of all
• 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
• 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)
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
• T2 - hyperintense
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%
• X-ray & CT
Expand the bone with thinning of
the overlying bone.
• Fallen fragment sign: a
dependent bony fragment
within the lesion.
Seen when assosciated fracture is
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
CT and MRI add little to the diagnosis, but are however helpful in eliminating other
entities that can potentially mimic a simple bone cyst
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.
(e.g chondroblastoma, fibrous dysplasia, giant cell tumour (GCT), osteosarcoma)
43. • Location
Long bones – tibia & fibula (24%),
Spine 20-30% (posterior elements).
• A variant of ABCs is the giant cell
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.
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
• 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.
• 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
Lesions tend to have an eccentric
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
C+(Gd) : tends to show intense and homogeneous static enhancement,
although there is no uniform dynamic enhancement pattern.
• 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
• odontogenic keratocyst (OKC) -unilocular with thin poorly enhancing walls
• odontogenic myxoma - can be almost indistiguishable
• aneurysmal bone cyst (ABC)
• fibrous dysplasia
Enchondroma , Maffucii sybdrome and olliers disease will be discussed together.
INVOLVEMENT OF SOFT TISSUE IS ALMOST EXCLUSIVELY SEEN IN MAFUCCIS
Despite being rare, they are one of the most frequently encoutered benign epiphyseal neoplasms in skeletally immature patients.
*which may lead to the incorrect diagnosis of giant cell tumour) which may lead to the incorrect diagnosis of giant cell tumour)
cT demonstrates the plain film findings with better delineation of the relationship to the growth plate and articular surface
CHONDROBLASTOMA OF SCAPULA TIBIA
well defined lytic lesions; either smooth or lobulated margins with a thin sclerotic rim
Internal calcifications can be seen .
Fluid-fluid levels may occasionally be seen (see fluid fluid level containing bone lesions) presumably due to an associated aneurysmal bone cyst
T1 - lesion itself is of low to intermediate signal
T2 / STIR - lesion is of intermediate to high signa
T1 and t2 images see the cartilage differences .
Examples have however been seen in patients up to the age of 75 years. In some series there is a male predilection 12 whilst in others no such distribution is found
STIR T2 FAST SAT T1 t1 FAST c++
Tests like FNAC is usually non-diagnostic and is dominated by fresh blood
. Occasionally they are also seen in appendicular long bones where they are known as solid aneurysmal bone cysts. Histologically these two entities are identical 6.
fluid-fluid levels, no means unique to it, and is also seen in both benign and malignant lesions (e.g. giant cell tumours (GCT), chondroblastoma, simple bone cysts and telangiectatic osteosarcomas).
Also seen in giant cell tumour
simple bone cyst
On plain films (and to a lesser degree CT) the diagnosis includes most of the lesions
Allows detailed in view of the lesion can be of two types in general
the rightmandible with expansion of buccal and lingual cortical plates. Ameloblastoma
Explain the graphs
In some locations, such as in the humerus or around the knee, almost all bone tumors may be found.
Simple bone cyst
Anteroposterior radiograph of the pelvis shows expansile lytic lesion of right acetabulum with thinning of the cortex (arrow) and honeycomb trabeculation. Flat bones are a common location for aneurysmal bone cysts
Anteroposterior radiograph of proximal portion of tibia and fibula shows expansile lytic lesion in proximal fibular metaphysis, with mild honeycombing (black arrows). Eccentric origin of the lesion is hard to appreciate in thin bones such as the fibula; both cortices are ballooned, with focal loss laterally (white arrow).
Anteroposterior radiograph of distal forearm and wrist shows more typical eccentric location of aneurysmal bone cyst in distal metaphysis of the radius, although this particular lesion lacks a honeycomb appearance. Cortex on radial side is very thin
Lateral radiograph of proximal portion of tibia shows enchondroma with punctate and arclike mineralization (arrows).