Lecture no. 2Prepared by Dr.Salah Mohammad Fatih

MBChB,DMRD,FIBMS(radiology)

Bone tumors

Investigations;1- plain film radiography in general is the

best imaging technique for making the Dx.

2- MRI&CT often shows the full extend of the tumor & show the effects on the surrounding structures& the relation ship to the neurovascular bundles

3- Isotope scan is used to Dx metastatic bone disease

Primary bone tumors1- malignant2- benign

1- primary malignant bone tumors

1- plain radiograph; usually have;Poorly defined margin.Wide zone of transition.Lesion may destroy the cortex.Periosteal reaction is often present.Soft tissue mass may be seen.

Poorly defined margin & wide zone of transition.

Soft tissue mass

destroy the cortex

Periosteal reaction

2- Isotope scanMalignant bone tumor show increased activity in the lesion.

3-MRIMRI is the most accurate technique in

showing the local extend of the tumor with the advantage that images may be produced in coronal & sagittal planes & MRI provides this information better than CT

Osteosarcoma(osteogenic sarcoma)

Age ; mainly 5-20 years but also seen in elderly following malignant transformation of paget’s disease.

Location;Is often arise in the metaphysis, most commonly around the knee joint.

X-ray finding;1.often there is bone destruction & new bone

formation with typical florid speculated periosteal reaction(sunray appearance).

2.The tumor may elevate periosteum to form Codman’s triangle

Chondrosarcoma Age; 30-60 yearsSite; most common sites are pelvic bones,scapulae,

humeri & femoraRadigraphic finding;1.It produce lytic expansile lesion contains flecks of

calcification.2.It can be difficult to be distinguished from its

benign counterpart (enchndroma), but condrosarcoma usually less well defined in at least one portion of its outline & may show a periosteal reaction & soft tissue component. chondrosarcoma may arise from malignant degeration of the benign cartilaginous tumors.

Fibrosarcoma & malignant fibrous histocytosisAre rare tumors.Age; mostly in young & middle age Site ; usually around the knee joint.X-ray finding;Ill defined area of lysis with periosteal

reactionFrequently the cortex is breached.There are no imaging features that

distinguish these tumors from secondary or lymphoma.

Ewing sarcomaIs a highly malignant tumor.Age; most commonly occur in the

children ,usually between 5-15 years. site; it arise mostly in the long bone, usually

in diaphyseal region.X-ray finding;It produce an ill define bone destruction with

periosteal reaction that is typically onion skin in appearance.

Giant cell tumor

Has features of both malignant & benign tumor, it is locally invasive but rarely metastasizes.

Age; usually 20-40 years. site; it is most commonly occur around the

knee & wrist after the epiphysis have fused.X-ray finding;Expanding destructive lesion which is

subarticular in position. the margin is fairly well defined but the cortex is

thin & may be in places completely destroyed.

Primary lymphoma of boneIs rareMost osseous lymphoma is associated with

generalized lymph node disease.When solitary , bone lymphoma may produce

sclerotic bone lesions or they may cause destruction of the bone, producing image finding that can’t be distinguished from fibrosarcoma or malignant fibrous histiocytosis.

2-Benign bone tumors

Common x-ray finding;Narrow zone of transion with sclerotic rim.Cause expansion but rarely produce cortical

breakdown .There is no soft tissue mass . periosteal reaction is unusual unless there is

has been a fracture through the lesion.

Isotope scan; shows little or no increase in the activity unless fracture has been occurred through the lesion.

MRI & CT scan: are rarely needed in their evaluation

EnchndromaAre seen as lytic expanding lesion .Most commonly seen in the hand.They often contain flecks of calcium &

frequently present as a pathological fracture.

Hand multiple chondromas

Fibrus dysplasiaMay affect one or more boneIt occure most commonly in the long bones&

ribs.Radiologically it appear as lucent area with a

well defined edge and may expand the bone, there may be sclerotic rim around the lesion

Simple bone cyst Occurs in children & young adult.Most common sites are humerus & femurX-ray;Lucency across the width of the shaft of the

bone with well defined edge.The cortex may be thin & the bone expanded.Often the 1st clinical finding is pathological

fracture

Aneurysmal bone cystare neoplasm.Mostly seen in children & young adult.Common site; spine, long bone & pelvis.Radiological finding;1.X-ray; purely lytic & cause massive bone

expansion of the cortex.2.CT & MRI may show the blood pool within

the cyst.3.Major differential Dx is Giant cell tumor

Oseoid osteomaIs a painful condition found most commonly

in the femur & tibia in young adults.Radiological appearance; it has a

characteristic appearance;Small lucency sometime with central specks of

calcification (nidus) surrounded by dense sclerotic rim & periosteal reaction may be seen.

oseomyelitisUsually occur in infant& children.Initial radiographic appearance is normal &

bone changes are not visible until 10-14 days of the infection.

Most sensitive imaging modalities are isotope scan & MRI which may shows the disease within 1-2 days.

Acute oseomyelitisTypically affect metaphysis of the long bone.X-ray finding;The earliest sign on the plan radiograph is soft tissue

swelling with characteristic obliteration of fat plains & may be apparent with 1st 2 days of the clinical manifestations.

local osteoporosis may be seen within 10-14 days of the onset of the symptoms.

bone destruction in the metaphysis with periosteal reaction that eventually may become very extensive & surround the bone to form involucrum which is usually visualized after 3 weeks.

Part from the original bone may die & separate to form dense fragment called sequestrum.

sequestrum

Isotope scan; increased activity in both early & delay phase.

MRI; is the investigation of choice & may shows evidence of bone edema & pus accumulation in the bone & soft tissue

Chronic oseomyelitis

The bone become thickeneed & loss diferentiation between the cortex & the medulla

TB oseomyelitis

Spine is the most common site followed by large joints, but any bone may be affected.

The disease produce large areas of bone distruction & unlike pyogenic infection, the disease is relatively asymptomatic in the early stage.

Multiple focal lesions

Metastases & multiple myeloma are the commonest causes of multiple obvious lytic lesions in the bone,

metastases Is the commonest malignant bone tumor.Those bones contains red marrow are the commonest site to

be affected, namely spine, skull, ribs, pelvis, humeri & femora. lytic secondry depisite; in the adult most commonly from ,

breast & bronchus & less commonly from carcinoma of the thyroid, renal, colon & in the children from neuroblastoma.

Radiologically appearce as a well-defined or ill-defined areas of bone destruction without sclerotic rim.

Sclerotic metastases; in the men most commonly from prostate & in the female from Ca breast, it appear as ill-defined areas of increased density of varying sizes with ill-defined margin.

Mixed lytic & sclerotic secondery deposite; they are most commonly from Ca breast

Notes;bone expansion uncommon in metastases except in Ca

thyroid & kidney. periosteal reaction is uncommon with metastases except in

neuroroblastoma. Isotope scan is much more sensitive than plain film in

detecting bone metastases & if multiple areas of increased activity are seen in a patient with known primary Ca, then the

Dx of metastases is virtually certain .MRI is better than isotope scan for detecting & it shows more

metastases but is more difficult to survey the whole skeleton with MRI.

CT less sensitive than MRI for detecting metastases, but can demonstrate lytic & sclerotic metastases & the image should be reviewed on bone windows .

Multiple myelomaThey are more commonly seen in active

heamopoetic areas .It is resemble lytic metastases but it is

often better defined.Diffuse marrow involvement may cause

generalized loss of bone density producing a picture similar to that of oseoporosis.

Most meyloma deposite show increased activity on isotope scan

Generalize decreased bone density(osteopenia)

Radiographic density of the bone depend on the amount of calcium present in the bone.

decrease in bone calcium lead to decrease in bone density.

1. Osteoporosis.2. Osteomalacia.3. Hyperparathyroidism.4. Multiple myeloma.

Main causes of generalized decrease in bone density;

Osteoporosis is the consequence of a deficiency of protein matrix(osteoid) & decrease amount of the normal bone (i.e. loss of bone mass) while remaining bone is normally mineralized (microstructure of the bone remain normal & histologically also normal)

osteoporosis

Osteoporosis predispose to fractures , specially vertebral bodies & hips.

1-Idiopathic; according to the age, subdivided to; Juvenile Senile Postmenopausal; up to 50% of female over 60

years of age have osteoporosis. 2-Cushing’s disease & steroid therapy.

3-disuse

Main Causes of osteoporosis

Change in bone density usually unapparent until 30-50% of the bone mass has been lost.

Decreased cortical thickness.

Decreased no. of the trabeculae present in the bone.

Radiological features

Empty box

Prminent vertical trabicuale

VB compression fracture

Generalized decrease in bone density

Changes best seen in the spine.Resorption of the horizontal trabeculae.Empty box ; apparent increased end plate

density due to Resorption of the spongy bone.VB compression fracture; wedged or

biconcave types with apparent widening of the disc spaces

Local decreased bone density caused by localized pain or immobilization of a fracture

Disuse osteoporosis

Indistinctness of the cortex of the right femoral head and osteopenia of the entire femoral head