Radiology of Bone Tumors

Dr Dhananjaya Sabat MS, DNB, MNAMSAssistant Professor OrthopedicsMaulana Azad Medical College, New Delhi

(1) Location of the lesion (2) Extent of the lesion (3) What is the lesion doing to the bone? (4) What is the bone doing to the lesion? (5) Hint as to its tissue type / matrix

X-rays - the question need to ask:

A. Location Location and age of patient most important

parameters in classifying a primary bone tumor.

Simple to determine from plain radiographs.

Location

EPIPHYSEAL◦ Chondroblastoma◦ Clear cell

chondrosarcoma◦ Giant cell tumor◦ Aneurysmal bone

cyst◦ Geode

(subchondral cyst)◦ Infection◦ Eosinophilic

granuloma

Location in Longitudinal Plane DIAPHYSEAL

◦ Adamantinoma ◦ Leukemia,

Lymphoma, Reticulum cell sarcoma

◦ Ewing sarcoma◦ Metastasis ◦ Osteoblastoma/

osteoid osteoma ◦ Nonossifying fibroma

METAPHYSEAL◦ Nonossifying fibroma

(close to growth plate)◦ Chondromyxoid fibroma

(abutting growth plate)◦ Solitary bone cyst, ABC,

GCT◦ Osteochondroma◦ Brodie abscess◦ Osteogenic sarcoma,

chondrosarcoma

Location in Transverse Plane

Central: Enchondroma Eccentric: GCT, CMF,

osteosarcoma Cortical: osteoid

osteoma, NOF Parosteal:

osteochondroma, parosteal osteosarcoma

Specific LocationBONE TUMOR COMMONEST SITESBC Proximal humerus > prox. FemurABC, GCT, Osteosarcoma Lowerend femur > upper end tibiaEnchondroma Metaphysis of small bones of hand & feetOsteochondroma Distal femur> prox. Tibia > prox. HumerusChondroblastoma Proximal humerus> prox femurEwing’s Femur > fibula > tibia Adamantinoma Mandible > tibiaMyeloma VertebraFibrous dysplasia Ribs > Upper femur > Tibia > lower femurOsteoid osteoma Femur > tibiaChordoma Sacrum > clivus (spheno occipital) > anterior

vertebral bodyIvory osteoma Frontal sinusChondromyxoid fibroma Tibia > femurChondroblastoma Pelvis > femurOsteoblastoma Posterior spine

Cysts and cyst like lesions of bone

Patterns of bone destruction:

Lytic

Sclerotic

B: What is the lesion doing to the bone?

• PERMEATIVE

• GEOGRAPHIC

• MOTHEATEN

Poorly 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 / irregular 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

Radiographic Margins Margin types 1A, 1B, 1C, 2, and 3

◦ least aggressive 1A, to most aggressive 3 Aggressive lesions destroy bone. Aggressiveness increases likelihood of

malignancy.◦ BUT, not all aggressive processes are malignant.◦ AND, not all malignant diseases are aggressive.

Margins: 1A,1B,1C

increasing aggressiveness

A well circumscribed lesion with a narrow zone of transition

1A: sclerotic margin

simple cyst (UBC) enchondroma FD chondroblastoma GCT chondrosarcoma

(rare) MFH (rare)

1B: well-defined, non-sclerotic

GCT enchondroma chondroblastoma myeloma,

metastatsis CMF FD chondrosarcoma MFH

1C: lytic, ill-defined margins

chondrosarcoma MFH osteosarcoma GCT metastasis infection EG lymphoma

2: “motheaten”

myeloma, metastases

infection EG osteosarcoma chondrosarcoma lymphoma

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

3: “permeative” Ewing EG infection myeloma,

metastasis lymphoma osteosarcoma

Poorly 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 reaction

Rate of growth determines bone response◦ slow progression, sclerosis prevails◦ rapid progression, destruction prevails

B. Reaction of bone to tumor

Periosteal Reaction Periosteal reaction must mineralize to be

seen on X ray ( 10 days – 3 weeks) Configuration of periosteal reaction

◦ Nature of inciting process◦ Intensity◦ Aggressiveness◦ Duration

Periosteal Reaction

Thick, uninterrupted◦ long standing process, often non-aggressive

stress fracture chronic infection osteoid osteoma

Spiculated, lamellated◦ aggressive process◦ tumor likely

Codman Triangle

periosteal reaction

tumor

advancing tumor margin destroys periosteal new bone before it ossifies

CodmanTriangle

Sunburst Appearance

C: Tumor Matrix

“Matrix” is the internal tissue of the tumor Most tumor matrix is soft tissue in nature.

◦ Radiolucent (lytic) on x-ray Cartilage matrix

◦ calcified rings, arcs, dots (stippled)◦ enchondroma, chondroblastoma, chondrosarcoma

Ossific matrix ◦ osteosarcoma

http://www.indyrad.iupui.edu/public/ddaven/Tumors/set1/case1/page.htm

OsteochondromaExostosis: well defined

bony projection growing away from physis

Cartilage maybe calcified if lesions are large / malignant change

Osteoid osteoma Nidus: a tiny radiolucent area If in diaphysis surrounded by dense bone and thickened cortex Metaphysis less cortical thickening Double density sign on bone scan – increased uptake in nidus and

decreased uptake in reactive sclerotic zone (also seen in Brodie’s abcess) Lytic nidus surrounded by sclerotic bone in CT Centre of nidus may be calcified

Well demarcated osteolytic lesion sometimes containing flecks of calcification

Less reactive bone than osteoid osteoma Bone scan - intense activity

Osteoblastoma

Cystic radiolucency on the diaphysial side of the growth plate Cortex may be thinned and bone expanded with well defined thin

sclerotic margin May have pseudo-loculated appearance secondary to irregular

cortical thinning and thin septal ridges Falling fragment sign typical and the lesion is never wider than

epiphysial plate Bone scan cold or minimal activity unless fractured

Simple bone cyst

Gross honey comb lesion Often eccentrically placed Does not extend to the joint (unlike GCT) Warm to hot on bone scan

Aneurysmal bone cyst

Usually well defined geographic lytic lesion in the epiphysis/metaphysis extending up to the joint surface without marginal sclerosis

Junction with normal bone often poorly defined Cortex thinned and sometimes ballooned Bone scan warm to hot

Giant cell tumor

Fibrous cortical defect Margin well defined, sometimes scalloped and often

sclerosed

Geographic Well marginated Multilocular appearance Inter cortical osteolysis - single or multiple bubble like areas

Non-ossifying Fibroma

Ground glass appearance typical Shepherds crook deformity of proximal femur Variable appearance with expansion of cortex

Fibrous Dysplasia

Scalloped erosions on endosteal surface May have flecks of calcification

Enchondroma

Rounded or oval rare area Usually eccentrically placed May cross the growth plate Sharp outline and sclerotic rim Scalloped margin and thin cortex

Chondromyxoid fibroma

Well defined area of rarefaction eccentrically placed in the epiphysis or across the growth plate

No reaction in surrounding bone 50% show central calcification, 50% show linear

periosteal reaction Bone scan increased uptake at margins

Chondroblatoma

Multiple loose bodies

Synovial Chondromatosis

Large osteolytic lesion in the midline May contain flecks of calcification Marked bone destruction

Chordoma

Diffuse osteopenia with multiple osteolytic lesions dispersed throughout skeleton.

Brown Tumor

Characteristic honey comb appearance in diaphysis

Cortical thinning with expansion

Adamantinoma

Vertical striations without bone expansion and coarse trabecular appearance (corduroy appearance)

Hemangioma

Mottled lytic defect usually no sclerotic rim

May destroy cortex Usually endosteal or periosteal reaction Lesions in flat bones and ribs appear

punched out May appear loculated due to sparing of

large trabeculae Spinal lesions- collapse (vertebra

plana), which may heal

Eosinophillic granuloma

Mottled or moth eaten lesion diffusely involving bone

Lytic destruction common, often the cortex is perforated

Onion skin appearance- layers of periosteal new bone are said to be characteristic

May form Codman’s triangle

Ewing’s sarcoma

Variable with combination of bone destruction and bone formation

Sun ray spicules/ sun burst appearance and Codman’s triangle may be evident

Cortical breach common Adjacent soft tissue mass Joint space rarely involved

◦ 25% Lytic◦ 35% Sclerotic◦ 40% Mixed

Telangiectatic type- purely lytic

Osteosarcoma

Variable appearance with 60 - 70% have calcification and 50% have sub periosteal new bone

May be a large cystic lesion with cortical destruction and central calcification, endosteal scalloping and cortical expansion; annular, punctate or comma shaped calcification

Chondrosarcoma

Bone often mottled or moth eaten with extension into soft tissue

Osteolytic lesion may be surrounded by reactive bone

Destructive appearance radiologically Usually little periosteal reaction

Fibrorosarcoma

METASTATIC BONE DISEASE Osteolytic commonest - cortical destruction with

little or no periosteal reaction; Lungs, Kidney, Adrenal, Thyroid, Uterus

Osteoblastic deposits – Prostate, Bladder, Testis, Breast and Bowel secondaries. Also carcinoid lung tumors, lymphoma

Mixed- Breast, Lung, Ovary, Cervix Lymphoma deposits may resemble prostatic

deposits, i.e. sclerotic secondaries Lytic, expansile, with soft tissue mass- RCC, thyroid X-Ray- at least 50% loss of bone to produce lysis on

X-ray, Loss of single pedicle produces a “winking owl sign”. CT scan, MRI

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

Osteoblastic bone metastases

Mixed pattern bone metastases:

Early - vague mottled lucent areas Diffuse destructive lytic lesion with little periosteal

reaction Usually combination of patchy sclerosis and mottled

destruction Hogkins disease - typical appearance of ivory

vertebrae

Lymphoma

May be generalised decrease in bone density Multiple punched out defects Little bony reaction around lesions Solitary lesion = plasmacytoma; multilocular expanding lytic

lesion in a red marrow area Frequently cold on bone scan

Myeloma