X-ray: Most useful of all imaging techniques.There might be obvious abnormality of the bone:Cortical thickeningDiscrete lumpCystdefined destruction

Is it in the metaphysis or diaphysis?Is it solitary or multiple lesions?Margins are well or ill defined?Note: cystic lesions are not necessarily hollow cavities: any radiolucent material may look like a cyst (e.g fibroma and chondroma)If the boundaries of the cyst is well defined, then it is mostly benign.If it is hazy and diffuse it is mostly invasive tumor.Bone surfaces: periosteal new bone formation and extension of the tumor to the soft tissues are suggestive of a malignant tumor.

Soft tissues: are the muscle planes distorted by the swelling? Is there any calcification?

X-ray is not a definitive diagnosis and further investigation must be done to confirm.

Other techniques of imaging used are:-Radionuclide scanning-reveals site of small tumourCT-shows more accurately intraosseous and extraosseous extension of tumourMRI-useful for assessment of tumour spreadThey all help in viewing the lesions better, view soft tissue and detect skip lesions too.Patient must not go for biopsy if MRI or CT is planned for him as it will distort the image and appearances.

Imaging analysis: benign or malignant histologyLocation of the lesionNumber of the lesionBony destructionHyperostosisPeriosteal reactionSurrounding soft tissue changeschondroblastoma

Location and age of patient most important parameters in classifying a primary bone tumor.Simple to determine from plain radiographs.

Location of the lesion Giant cell tumor: ending of long boneOsteosarcoma: metaphysis of long boneEwing sarcoma: diaphysisMyeloma, metastasis tumor: flat bone, irregular bone

Central: EnchondromaEccentric: GCT, CMF, osteosarcomaCortical: osteoid osteoma, NOFParosteal: osteochondroma, parosteal osteosarcoma

B Number of lesionPrimary tumor: single frequentMetastasis: multipleMyeloma: multipleMultiple Myeloma Osteogenic metastasisGiant cell tumor

Patterns of bone destruction:

Lytic

Sclerotic

PERMEATIVE GEOGRAPHICMOTHEATENPoorly demarcated lesion imperceptibly merging with uninvolved boneLong zone of transitionAreas of destruction with ragged borders. Less well defined / demarcated lesional margin Longer zone of transition Well-defined smooth marginShort zone of transition

Margin between tumor and native bone is visible on the plain radiograph.Slowly progressive process is walled-off by native bone, producing distinct margins.Rapidly progressive process destroys bone, producing indistinct margins.

Margin types 1A, 1B, 1C, 2, and 3least aggressive 1A, to most aggressive 3Aggressive lesions destroy bone.Aggressiveness increases likelihood of malignancy.BUT, not all aggressive processes are malignant.AND, not all malignant diseases are aggressive.

increasing aggressivenessA well circumscribed lesion with a narrow zone of transition

simple cyst (UBC)enchondromaFD chondroblastomaGCTchondrosarcoma (rare)MFH (rare)

GCTenchondromachondroblastomamyeloma, metastatsisCMFFDchondrosarcomaMFH

chondrosarcomaMFHosteosarcomaGCTmetastasisinfectionEGlymphoma

myeloma, metastasesinfectionEGosteosarcomachondrosarcomalymphoma

Multiple scattered holes that vary in size & seem to arise separately

EwingEGinfectionmyeloma, metastasislymphomaosteosarcomaPoorly demarcated from normal, numerous elongated holes/slots in cortex, run parallel to long axis of bone

Limited responses of bone Destruction:lysis (lucency) Reaction:sclerosis Remodeling:periosteal reactionRate of growth determines bone responseslow progression, sclerosis prevailsrapid progression, destruction prevails

Periosteal reaction must mineralize to be seen on X ray Configuration of periosteal reactionNature of inciting processIntensityAggressivenessDuration

Thick, uninterruptedlong standing process, often non-aggressivestress fracturechronic infectionosteoid osteomaSpiculated, lamellatedaggressive processtumor likely

periosteal reactiontumoradvancing tumor margin destroys periosteal new bone before it ossifiesCodmanTriangle

Sunburst Appearance

Matrix is the internal tissue of the tumorMost tumor matrix is soft tissue in nature.Radiolucent (lytic) on x-rayCartilage matrixcalcified rings, arcs, dots (stippled)enchondroma, chondroblastoma, chondrosarcomaOssific matrix osteosarcoma

Osteolytic bone metastases: breast carcinoma shows multiple osteolytic bone lesions.

Osteoblastic bone metastases

Mixed pattern bone metastases:

LABORATORY INVESTIGATIONS

Blood Test : +ESR,+ ALP and Anemia are non specific markers but may help in differentiating between malignant and benign bone lesion

Osteosarcoma: Alkali Phosphatase (ALP)Ewing's sarcoma: WBCmetastatic tumor & myeloma: secondary anemia and blood calciumMyeloma: Bence-Jones protein in urine

There are three ways:

1.Needle biopsy: Must be performed by experienced personal with help of US or CT scan2. Open biopsy: most reliable way of obtaining a representative sample.3. Excisional biopsy: for benign tumors.Principles of biopsy

From boundary or edge of tumorTake several samplesIncision strategically placedIdeally done by the treating surgeonWound closed without drain

It is frequently associated withosteosarcomabut can also occur with other aggressivebony lesions such as anEwing sarcoma.*is the triangular area of newsubperiostealbone that is created when a lesion, often a tumour, raises theperiosteumaway from the bone***