Image Interpretation Course Bone Tumors

8/3/2019 Image Interpretation Course Bone Tumors

1/16

Image Interpretation Course

by Heidi Nunn DCR(R) PgCert

Bone Tumours and Benign Lytic Lesions

Factors aiding diagnosis| Benign lesions | Malignant tumours | Osteomyelitis

Non-ossifying fibroma | Solitary bone cyst | Aneurysmal bone cystEnchondroma | Haemangioma | Fibrous dysplasia | Giant cell tumour

Osteosarcoma | Ewing's sarcoma | Chondrosarcoma | Metastases | Multiple

myeloma

When interpreting whether an image is normal or abnormal, it is common to come

across incidental lytic lesions, which, depending on their appearance, must be

classified as either a normal variant, or something which warrants further

investigation.

It is difficult to determine radiologically with plain film imaging if a lytic lesion is

benign or malignant. It is more accurate to describe whether the process looks

aggressive or non-aggressive. Some factors, as outlined below, help to determine

whether a lesion looks aggressive or non-aggressive, and therefore the differential

diagnosis.

It is important to remember, however, that some benign processes such as

osteomyelitis, can mimic malignant tumours, and some malignant lesions, such asmetastases or myeloma, can look benign.

Factors aiding in the diagnosis of bone tumours and benign lytic lesions:

Age of patient
http://www.imageinterpretation.co.uk/tumour.html#diagnostichttp://www.imageinterpretation.co.uk/tumour.html#benignhttp://www.imageinterpretation.co.uk/tumour.html#malignanthttp://www.imageinterpretation.co.uk/tumour.html#osteomyelitishttp://www.imageinterpretation.co.uk/tumour.html#NOFhttp://www.imageinterpretation.co.uk/tumour.html#cysthttp://www.imageinterpretation.co.uk/tumour.html#aneurysmalhttp://www.imageinterpretation.co.uk/tumour.html#enchondromahttp://www.imageinterpretation.co.uk/tumour.html#haemangiomahttp://www.imageinterpretation.co.uk/tumour.html#dysplasiahttp://www.imageinterpretation.co.uk/tumour.html#giant_cell_tumourhttp://www.imageinterpretation.co.uk/tumour.html#osteosarcomahttp://www.imageinterpretation.co.uk/tumour.html#Ewinghttp://www.imageinterpretation.co.uk/tumour.html#chondrosarcomahttp://www.imageinterpretation.co.uk/tumour.html#metastatichttp://www.imageinterpretation.co.uk/tumour.html#myelomahttp://www.imageinterpretation.co.uk/tumour.html#myelomahttp://www.imageinterpretation.co.uk/tumour.html#benignhttp://www.imageinterpretation.co.uk/tumour.html#malignanthttp://www.imageinterpretation.co.uk/tumour.html#osteomyelitishttp://www.imageinterpretation.co.uk/tumour.html#NOFhttp://www.imageinterpretation.co.uk/tumour.html#NOFhttp://www.imageinterpretation.co.uk/tumour.html#cysthttp://www.imageinterpretation.co.uk/tumour.html#aneurysmalhttp://www.imageinterpretation.co.uk/tumour.html#enchondromahttp://www.imageinterpretation.co.uk/tumour.html#enchondromahttp://www.imageinterpretation.co.uk/tumour.html#haemangiomahttp://www.imageinterpretation.co.uk/tumour.html#dysplasiahttp://www.imageinterpretation.co.uk/tumour.html#giant_cell_tumourhttp://www.imageinterpretation.co.uk/tumour.html#osteosarcomahttp://www.imageinterpretation.co.uk/tumour.html#Ewinghttp://www.imageinterpretation.co.uk/tumour.html#chondrosarcomahttp://www.imageinterpretation.co.uk/tumour.html#metastatichttp://www.imageinterpretation.co.uk/tumour.html#myelomahttp://www.imageinterpretation.co.uk/tumour.html#myelomahttp://www.imageinterpretation.co.uk/tumour.html#diagnostic


2/16

Specific lesions tend to occur in specific age ranges. Solitary bone cysts,

non-ossifying fibromas, aneurysmal bone cysts and Ewings tumours occur in

patients under the age of 30 years. Metastases and myeloma will usually

occur in patients over the age of 40

Location within the bone

Epiphyseal, metaphyseal or diaphyseal

Central within the bone, eccentric or cortical

Lesions often arise within specific bones, and within specific areas of that

bone. Giant cell tumours for example, usually arise within the distal femur

or proximal tibia, and will always abut (push against) the articular surface

Size of lesion

Size of lesion is not necessarily an indication of how aggressive the process

is, but recognition that specific lesions have a tendency to grow larger can

help lead to the correct diagnosis. Solitary bone cysts within the proximal

humerus, for example, often become large. A large lytic lesion is at risk of

fracturing and it is therefore often prophylactically packed to prevent

fracture and subsequent deformity

Monostotic (one lesion) or polyostotic (multiple lesions)

Multiple lesions are also not necessarily indicative of an aggressive process.Although metastases and myeloma are usually multiple, most aggressive

processes demonstrate a single lesion. Similarly, benign enchondromas often

become multiple within the phalanges

Zone of transition from normal to abnormal bone

This is often the best indicator as to whether a lesion is aggressive or non-

aggressive. A very definite, sharp, and therefore narrow area (zone) between

the normal and abnormal bone indicates a non-aggressive lesion. A wide,

hazy, and undefined zone of transition suggests a more aggressive process.However, be aware that some benign processes (osteomyelitis) have a wide

zone of transition as they are fast acting

Reactive sclerosis

If there is a sclerotic margin to the lesion, it is most likely non-aggressive


3/16

Pattern of bone destruction

Geographic = Well defined margin; non-aggressive lesion

Moth-eaten = Less defined margin

Permeative = Poorly demarcated with multiple small irregular holes.

Suggests aggressive process

Presence of visible tumour matrix

Cartilage = Stippled (CJ) matrix

Osteoid = Sclerotic

Host (bone) response

Cortical thinning, expansion and penetration. Cortical destruction suggests

an aggressive process. Be aware, however, that what may appear to be

cortical destruction may actually be cortical bone replacement by a fibrous

or chondroid matrix, which is non-calcified and may be located within a

benign lesion. This gives the false impression of cortical destruction when it

is actually cortical replacement. Aneurysmal bone cysts, for example, often

cause such thinning of the cortex as to make it undetectable

radiographically.

Periosteal reaction

Periosteal reaction will occur whenever the periosteum is irritated. This may

be due to a malignant process, a benign lytic lesion, osteomyelitis, or

trauma. The appearance of the periostitis will give an indication as to cause:

Benign periostitis looks thick, wavy, dense and uniform, as it is slow

growing and therefore gives the periosteum time to lay down new bone.

Aggressive periostitis is often described as lamellated (onion-skinned),

amorphous and sunburst as the periosteum does not have time to

consolidate.

Soft tissue involvement

Aggressive lesions often lead to cortical breakthrough to create soft tissue

mass


4/16

BENIGN LYTIC LESIONS

Non-Ossifying Fibroma / Fibrous Cortical Defect

One of the most common benign lytic lesions seen

Asymptomatic and usually an incidental finding Most often seen around the knee and distal tibia

Non-Ossifying fibroma generally bigger than 2cm

Fibrous Cortical Defect generally smaller than 2cm

Arises in under 30 year age group

Develops from cortex of metaphysis; is eccentric within the bone

Bubbly

Usually has thin, sclerotic border that is often scalloped and slightly

expansile

Become sclerotic as healing occurs and disappears as it ossifies Therefore not seen in over 30 age group
http://www.imageinterpretation.co.uk/images/tumour/NOF%20knee%20-%20Lat.jpghttp://www.imageinterpretation.co.uk/images/tumour/NOF%20knee%20-%20AP.jpg


5/16

Simple / Solitary Bone Cyst


Begins within the physeal growth plate and extends into diaphysis

Centrally located within a long bone

Most commonly occurs in the proximal humerus

In the calcaneum it is triangular, and located antero-inferiorly as this is an

area that does not receive stress, and therefore develops atrophy of the bony

trabeculae

Also called unicameral bone cyst, however there is not always just one

compartment

Asymptomatic, unless it is fractured, which often occurs

"Falling fragment sign": cortical fragments produced from pathological

fracture, that have sunk to the bottom of the fluid filled lesion
http://www.imageinterpretation.co.uk/images/tumour/SBC%20calcaneum.jpghttp://www.imageinterpretation.co.uk/images/tumour/SBC%20humerus%20AP.jpg


6/16

Aneurysmal Bone Cyst


Presents with pain

Expansile

Differential diagnosis: osteoblastoma, as very similar in appearance

Enchondroma

Most commonly seen in the phalanges

Asymptomatic but commonly fractures

Well-defined with narrow zone of transition Lobulated

Can become slightly expansile

Causes endosteal scalloping and cortical thinning

Olliers Disease = Multiple enchondromas

Maffuccis Syndrome = Multiple enchondromas with soft tissue

haemangiomas
http://www.imageinterpretation.co.uk/images/tumour/ABC%20shoulder%20-%20Lat.jpghttp://www.imageinterpretation.co.uk/images/tumour/ABC%20shoulder.jpg


7/16

Contain calcified chondroid matrix (irregular, speckled) when located away

from phalanges

Differential diagnosis: bone infarct. This often occurs within femur or tibia

and typically demonstrates patchy sclerosis with demineralisation
http://www.imageinterpretation.co.uk/images/tumour/Multiple%20enchondromas%20with%20fracture.jpghttp://www.imageinterpretation.co.uk/images/tumour/Enchondroma%20and%20fracture%202.jpg


8/16

Haemangioma

Benign vascular tumour Vertebral haemangioma; solitary lesion within vertebral body typically

demonstrates coarse vertical trabecular pattern

Usually asymptomatic and incidental finding
http://www.imageinterpretation.co.uk/images/tumour/bone%20infarct%20distal%20femur-%20lat.jpghttp://www.imageinterpretation.co.uk/images/tumour/bone%20infarct%20distal%20femur-%20ap.jpg


9/16

However, within vertebral body occasionally causes symptoms of spinal

cord compression
http://www.imageinterpretation.co.uk/images/tumour/Haemangioma%20T8%20-%20Lat.jpghttp://www.imageinterpretation.co.uk/images/tumour/Haemangioma%20T8%20-%20AP.jpg


10/16

Fibrous Dysplasia

Long lesion in a long bone (often occurs in proximal femur)

Expansion and bone deformity

Lytic but becomes ground-glass in appearance as the matrix calcifies, and

then becomes sclerotic

Asymptomatic, but can fracture

No periosteal reaction


11/16

May be single or multiple lesion in different locations

Giant Cell Tumour

Epiphyses must be closed

Must be epiphyseal and abut the articular surface

Well-defined with narrow zone of transition Must have a non-sclerotic margin

Eccentric within the bone

Usually occurs within the distal femur or proximal tibia
http://www.imageinterpretation.co.uk/images/tumour/Fibrous%20dysplasia%20tibia.jpghttp://www.imageinterpretation.co.uk/images/tumour/Fibrous%20dysplasia%20femur.jpg


12/16

15per cent become malignant based on recurrence rate or subsequent

metastases

MALIGNANT BONE TUMOURS

Osteosarcoma

Most common malignant primary bone tumour

Arises in under 30 year age group, but also has a second peak at 60 years

Presents with pain

Usually occurs towards end of long bone

Aggressive with a wide zone of transition

Often demonstrates cortical destruction Sclerosis present from either tumour new bone or reactive sclerosis
http://www.imageinterpretation.co.uk/images/tumour/GCT%20knee%20%20before%20cement%20filled%20Lat.jpghttp://www.imageinterpretation.co.uk/images/tumour/GCT%20knee%20%20before%20cement%20filled%20AP.jpghttp://www.imageinterpretation.co.uk/images/tumour/GCT%20tib%20-%20Lat.jpghttp://www.imageinterpretation.co.uk/images/tumour/GCT%20tib%20-%20AP.jpg


13/16

Ewing's sarcoma


Permeative lesion usually in diaphysis of long bone

Often have onion-skinned or sunburst type of periostitis

Chondrosarcoma

Looks similar to enchondroma, but is painful Seen in over 40 year age group

Lytic, destructive lesion with calcified chondroid matrix that looks

amorphous and irregular with snowflake-like calcification
http://www.imageinterpretation.co.uk/images/tumour/infection%20shoulder.jpghttp://www.imageinterpretation.co.uk/images/tumour/Osteosarcoma.jpg


14/16

Metastatic Disease

May demonstrate single or multiple, lytic or sclerotic lesions

Can look benign or aggressive

When aggressive, often is described as having moth-eaten or permeative

appearance

Difficult to ascertain origin of primary

Metastases from a primary renal tumour will always demonstrate lytic

lesions

Breast primary often develops lytic metastases

Multiple sclerotic lesions, particularly in the pelvis (in an elderly man) will

usually have prostate primary Painful, and often develops pathological fracture with little trauma

Multiple Myeloma
http://www.imageinterpretation.co.uk/images/tumour/Met%20lt%20pelvis.jpghttp://www.imageinterpretation.co.uk/images/tumour/Met%20CSP.jpghttp://www.imageinterpretation.co.uk/images/tumour/Chondrosarcoma%20LSP%20-%20AP.jpg


15/16

May be solitary or multiple lytic lesions (plasmacytomas)

Radiologically, often precedes clinical or haematological presentation of

myeloma

Not always hot on radionuclide imaging; skeletal survey more useful for

diagnosis

Diffuse and permeative lytic lesions

Usually age range over 35 years
http://www.imageinterpretation.co.uk/images/tumour/Myeloma%20spine.jpghttp://www.imageinterpretation.co.uk/images/tumour/Myeloma%20femur.jpghttp://www.imageinterpretation.co.uk/images/tumour/Myeloma%20humerus.jpghttp://www.imageinterpretation.co.uk/images/tumour/Myeloma%20skull.jpg


16/16

OSTEOMYELITIS

Usually presents as an aggressive lucency with a wide zone of transition

However, can also be sclerotic and look non-aggressive Painful

If occurring around a joint, the adjacent articular surface will be involved

Blurring of soft tissue fat planes / effusion

Osteopenia

Intramedullary destruction

Cortical destruction

Periosteal reaction

Bone dies (sequestrum)

New bone formation (involucrum)
http://www.imageinterpretation.co.uk/images/tumour/infection%20proximal%20tibia%20-%20lat.jpg

Documents

Image Interpretation Course Bone Tumors