This document provides information on classifying primary bone tumors based on location and radiographic appearance. Key points include: - Location within the bone (epiphyseal, diaphyseal, metaphyseal) and age of the patient help classify tumors. - Features like margins, extent of bone destruction/formation, and presence of a matrix provide clues about tissue type and aggressiveness. - Common sites for different tumors are listed to aid diagnosis. - Patterns of bone destruction (lytic, motheaten) and periosteal reactions further characterize lesions.

1. By
Tarek A. ElHewala
Lecturer of Orthopaedic Surgery
Faculty of Medicine – Zagazig University

2.  (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

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

5.  EPIPHYSEAL
◦ Chondroblastoma
◦ Clear cell
chondrosarcoma
◦ Giant cell tumor
◦ Aneurysmal bone
cyst
◦ Geode
(subchondral cyst)
◦ Infection
◦ Eosinophilic
granuloma
 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

6.  Central: Enchondroma
 Eccentric: GCT, CMF,
osteosarcoma
 Cortical: osteoid osteoma,
NOF
 Parosteal: osteochondroma,
parosteal osteosarcoma

7. BONE TUMOR COMMONEST SITE
SBC Proximal humerus > prox. Femur
ABC, GCT, Osteosarcoma Lowerend femur > upper end tibia
Enchondroma Metaphysis of small bones of hand & feet
Osteochondroma Distal femur> prox. Tibia > prox. Humerus
Chondroblastoma Proximal humerus> prox femur
Ewing’s Femur > fibula > tibia
Adamantinoma Mandible > tibia
Myeloma Vertebra
Fibrous dysplasia Ribs > Upper femur > Tibia > lower femur
Osteoid osteoma Femur > tibia
Chordoma Sacrum > clivus (spheno occipital) > anterior
vertebral body
Ivory osteoma Frontal sinus
Chondromyxoid fibroma Tibia > femur
Chondroblastoma Pelvis > femur
Osteoblastoma Posterior spine

9. Patterns of bone destruction:
 Lytic
 Sclerotic
•PERMEATIVE
•GEOGRAPHIC
•MOTHEATEN
Poorly demarcated lesion imperceptibly
merging with uninvolved bone
Long zone of transition
Areas of destruction with ragged borders.
Less well defined / demarcated lesional margin
Longer zone of transition
Well-defined smooth / irregular margin
Short zone of transition

10.  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.

11.  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.

12. increasing aggressiveness
A well circumscribed lesion
with a narrow zone of
transition

13.  simple cyst (UBC)
 enchondroma
 FD
 chondroblastoma
 GCT
 chondrosarcoma
(rare)
 MFH (rare)

14.  GCT
 enchondroma
 chondroblastoma
 myeloma,
metastatsis
 CMF
 FD
 chondrosarcoma
 MFH

15.  chondrosarcoma
 MFH
 osteosarcoma
 GCT
 metastasis
 infection
 EG
 lymphoma

16.  myeloma,
metastases
 infection
 EG
 osteosarcoma
 chondrosarcoma
 lymphoma
Multiple scattered holes that vary in
size & seem to arise separately

17.  Ewing
 EG
 infection
 myeloma,
metastasis
 lymphoma
 osteosarcoma
Poorly demarcated from normal, numerous
elongated holes/slots in cortex, run parallel to
long axis of bone

18.  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

19.  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

20.  Thick, uninterrupted
◦ long standing process, often non-aggressive
 stress fracture
 chronic infection
 osteoid osteoma
 Spiculated, lamellated
◦ aggressive process
◦ tumor likely

22. periosteal reaction
tumor
advancing tumor margin
destroys periosteal new
bone before it ossifies
Codman
Triangle

23. Sunburst Appearance

24.  “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

27.  Exostosis: well defined bony
projection growing away from
physis
 Cartilage maybe calcified if
lesions are large / malignant
change

28.  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

29.  Well demarcated osteolytic lesion sometimes
containing flecks of calcification
 Less reactive bone than osteoid osteoma
 Bone scan - intense activity

30.  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

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

32.  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

33. Fibrous cortical defect
 Margin well defined, sometimes scalloped
and often sclerosed

34. Non-ossifying Fibroma

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

36.  Scalloped erosions on endosteal surface
 May have flecks of calcification

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

38.  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

39.  Multiple loose bodies

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

41.  Diffuse
osteopenia with
multiple
osteolytic lesions
dispersed
throughout
skeleton.

42.  Characteristic honey comb appearance in
diaphysis
 Cortical thinning with expansion

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

44.  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

45.  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

46.  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

47.  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

48.  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

49.  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

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

52. Osteoblastic bone metastases

53. Mixed pattern bone metastases:

54.  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

55.  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