Lecture prepared by UKM Radiology registrar

1. MALIGNANT BONE TUMORS
Presenter: Tan Hooi Lam
Supervisor: Dr Nik Farhan

2. INTRODUCTION
• Classified into:
• Primary (30%)
• Secondary – bone metastasis (70%)
• Classified according to the normal cell of origin and apparent pattern of
differentiation
• Primary - 1% of all malignant tumors.
• Commonest primary - multiple myeloma, osteosarcoma, chondrosarcoma, Ewing’s
sarcoma

3. CLASSIFICATION OF PRIMARY TUMORS INVOLVING BONES

4. PRIMARY MALIGNANT BONE TUMOURS
1. Multiple myeloma
2. Osteosarcoma
• Conventional
• Non-conventional
3. Chondrosarcoma
4. Ewing’s sarcoma
5. Chordoma

6. MULTIPLE MYELOMA
o Most common primary malignant bone tumor >40y.o
o Clinical presentation:
• Bone pain, anaemia, renal failure.
• Pathological fracture such as vertebra compression fracture.
• Lab findings: Proteinuria-Bence jones protein, hypercalcaemia, low albumin levels.
o Imaging features:
• Vast majority of lesions are purely lytic (3% sclerotic)
• Sharply defined/punched out lesions
• Endosteal scalloping when abutting cortex.

7. o Four main patterns are recognised:
• Disseminated form: multiple well-defined "punched out" lytic lesions:
predominantly affecting the axial skeleton
• Disseminated form: diffuse skeletal osteopaenia
• Solitary plasmacytoma: single large/expansile lesion most commonly in a
vertebral body or in the pelvis
• Osteosclerosing myeloma
MULTIPLE MYELOMA

8. MULTIPLE MYELOMA –
RADIOGRAPHIC FEATURES
• Multiple well-defined punched out
lesions
• Plasmacytoma – solitary large expansile
lesion – early stage of MM
• Endosteal scalloping
• Cortical erosion
• No periosteal formation
• Spine – vertebral collapse sparing
posterior elements, paraspinal soft
tissue mass.
• Sclerosis after therapy

9. Multiple punched-out lesions in the
skull.Also known as swiss cheese-
pattern.
MULTIPLE MYELOMA

10. A large lytic lesion with well-
defined sclerotic border seen in
the left ilium of a patient with
MM.The ilium and sacrum are
common sites for plasmacytomas.
MRI appearance of plasmacytoma.Axial proton density (A)
andT2-weighted (B) images through a vertebral body with
a plasmacytoma show a characteristic appearance of a
mini-brain.
MULTIPLE MYELOMA

11. MULTIPLE MYELOMA VS METASTASIS
• The main differential of multiple lytic lesions in an adult is metastatic disease. Multiple myeloma originates
from the red marrow and usually does not involve regions where there is minimal red marrow, such as the
pedicles in the spine.
• Multiple myeloma may be negative on bone scan, unlike most metastases.
Metastasis Multiple myeloma

12. OSTEOSARCOMA
o Second most common malignant primary bone tumor after multiple myeloma
o Primary or secondary (ie. Paget’s disease or post irradiation)
o Primary osteosarcomas typically occur at the metadiaphysis of long bones in the
appendicular skeleton, most commonly at the following sites: femur (especially distal
femur), tibia (especially proximal tibia) and humerus
o Secondary tumors have a much wider distribution, largely mirroring the underlying
conditions, and thus much have a higher incidence in flat bones
o The four most important histologic subtypes are conventional (most common),
telangiectatic, parosteal and periosteal OS

13. CONVENTIONAL CENTRAL OSTEOSARCOMA
o Commonest form, 75%
o Typical presentation: pain and palpable mass.
o Classically affects metaphyseal of growing end of long bone.
o 75% in distal femur or prox tibia.
o Features:
• medullary and cortical bone destruction
• wide zone of transition, permeative or moth-eaten
appearance
• aggressive periosteal reaction (sunburst type, Codman
triangle, lamellated (onion skin) reaction: less
frequently seen)
• soft-tissue mass
• tumor matrix ossification/calcification (ill-defined
"fluffy" or "cloud-like”)

14. PAROSTEAL OSTEOSARCOMA
o Originates from the periosteum and grows outside of the bone.
o Commonly occurs at the posterior aspect of distal femoral
metaphysis.
o Patients are usually in their 3rd and 4th decades, older compared to
other osteosarcoma subtypes. Parosteal osteosarcoma is the least
malignant of all osteosarcomas, with 90% 5-year survival.
o Features:
• Large lobulated exophytic, 'cauliflower-like' mass with central
dense ossification adjacent to the bone
• String sign : thin radiolucent line separating the tumour from the
cortex, seen in 30% of cases
• Tumour stalk: grows within tumour in late stages and obliterates
the radiolucent cleavage plane
• +/- soft tissue mass
• Cortical thickening without aggressive periosteal reaction is often
seen
• Tumour extension into the medullary cavity is frequently seen

15. PERIOSTEAL OSTEOSARCOMA
o Type of surface osteosarcoma, is a rare
osteosarcoma variant arising from the inner
periosteum
o Histologically, periosteal osteosarcoma may
show chondroid differentiation
o The most common location of periosteal
osteosarcoma is the diaphysis of the femur or
tibia
o Patients tend to be younger than 20 years old
o Features:
• cortical thickening
• aggressive periosteal reaction
• soft-tissue mass

16. TELANGIECTATIC OSTEOSARCOMA
o Osteolytic destructive sarcoma
o Unlike other osteosarcomas, telangiectatic
osteosarcoma does not produce any bony matrix
o Pathologically, is vascular with large cystic spaces
filled with blood
o May mimic a benign aneurysmal bone cyst on
imaging
o The presence of solid nodular components on MRI
helps to differentiate a telangiectatic osteosarcoma
from a benign aneurysmal bone cyst

17. CHONDROSARCOMA
Tumour of connective tissue, formation of cartilage matrix by
tumour cells
Types:
1. Primary
2. Secondary: from pre-existing bone lesion (enchondroma,
osteochondroma)

18. CHONDROSARCOMA
o Radiographic features:
• A small low-grade
chondrosarcoma may not be
differentiated from a chondroma
• Well-defined lytic lesion with
chondroid matrix
• High grade tumor may present as
aggressive ill-defined lesion with
extension into the soft tissues
• Calcifications in 75%
• Deep endosteal cortical scalloping
• Periosteal reaction
o On plain radiographs the differential diagnosis
with enchondroma can be difficult.
Think of chondrosarcoma instead of
enchondroma if there is one or more of the
following features:
• Elderly patient
• Location in long bones
• Size > 5 cm
• Uptake on bone scan
• Endosteal scalloping on MRI
• Cortical involvement
• Early enhancement on dynamic contrast
enhanced series

19. CHONDROSARCOMA
Chondrosarcoma in the proximal tibia
diaphysis.
• Subtle calcifications in the proximal
part.
• Endosteal scalloping- a hallmark of
chondrosarcoma.
• MR better defines the extension of
the lesion. MRI also demonstrates the
endosteal scalloping.

20. CHONDROSARCOMA
Exophytic lesion arising from the right iliac crest,
which is continuous with the intramedullary
cavity. The lesion demonstrates ring and arc
chondroid-type calcification on radiography
T1WI: heterogeneously hyperintense with a
lobulated appearance

21. Intramedullary lesion with ring and arc chondroid calcifications.
Periosteal reaction and cortical disruption suggest aggressive behavior
CHONDROSARCOMA

22. Cortical involvement and expansion
should raise the suspicion of high grade
tumor
CHONDROSARCOMA

23. EWING’S SARCOMA
• Ewing’s sarcoma is a highly malignant small round
cell tumor (similar to PNET) affecting children and
adolescents with a male predominance
• Usually presents with pain
• Systemic symptoms including fever are often
present, making the distinction between Ewing’s
sarcoma and osteomyelitis difficult
• Ewing’s sarcoma is the second most common
pediatric primary bone tumor following
osteosarcoma

24. o Radiographic features:
• Permeative bone destruction
• Aggressive periosteal reaction
• Associated soft-tissue mass.
o In addition to Ewing’s sarcoma, the
differential of an aggressive lytic lesion in a
child includes
• osteomyelitis
• eosinophilic granuloma
• metastatic neuroblastoma
Mixed lytic-sclerotic, diaphysis, permeative, spiculated
periosteal reaction, soft- tissue extension
EWING’S SARCOMA

25. Large lytic tumor
Permeative
Difficult to appreciate on xray
EWING’S SARCOMA

26. CHORDOMA
• Rare tumors that arise from embryonic
notochordal remnants along the length of
the neuraxis at developmentally active sites
• Chordoma is a highly destructive lesion with
irregular scalloped borders
• Calcifications may be seen within the lesion.
These calcifications are due to necrosis, not
bone formation

27. CHORDOMA
Sacral chordoma. AP radiograph shows a central lytic destructive lesion.

28. • Lytic lesion C2/3
• Cortical destruction
• Soft tissue extension
• Compression onto spinal cord
• High signal on T2
CHORDOMA

29. SECONDARY BONE TUMORS
• Post radiation sarcoma
• Paget’s disease

30. POST RADIATION SARCOMA
o Criteria for diagnosis
• History of radiation therapy
• Development of a neoplasm in the radiation field
• Latent period of several years (min 3-4 years)
• Histological proof of sarcoma, which differ significantly from that initially treated
o Treated tumors that commonly results in PRS – breast, lymphoma, H&N, gynae
ca.
o Commonest PRS: osteosarcoma, MFH/undifferentiated pleomorphic sarcoma
o Commonest site: shoulder girdle and pelvis

31. Features:
• Cortical bone destruction
• Soft tissue mass
• Periosteal reaction
• Matrix mineralization
• Osteitis, marrow infarction on MRI
*Radiation-induced necrosis at left superior pubic
ramus
POST RADIATION SARCOMA

32. PAGET’S DISEASE – OSTEITIS DEFORMANS
o Metabolic osteoclastic disorder - abnormal osseous remodelling
o Commonly polyostotic and asymmetrical
o Unknown aetiology; may be caused by viral infection (paramyxovirus)
o Three classically described stages, which are part of a continuous spectrum:
1) Initial lytic (hot) phase: osteoclastic activity → bone resorption
2) Intermediate (mixed) phase: increased bone resorption → followed by formation of
coarse trabeculae → loss of corticomedullary differentiation
3) Late sclerotic (cold) phase: osteoblastic activity → disorganized bone of increased density

33. PAGET’S DISEASE – OSTEITIS
DEFORMANS
Location:
• Skull
• Weight bearing and persisting red marrow
areas (sacrum and lumbar spine > skull, pelvis
and femur)
• No bone is exempted but rarely fibula
involvement

34. Pathognomonic triad:
• Bone expansion
• Cortical thickening
• Trabecular bone thickening
PAGET’S DISEASE – OSTEITIS
DEFORMANS

35. XR
o SKULL: basilar invagination
• Osteoporosis circumscripta: initial lytic phase (sparing inner table) may persist within the
skull (predominantly affecting the frontal and occipital bones)
• ‘Cotton wool’ appearance: osteoporosis circumscripta progress to mixed pattern
o PELVIS: thickened ileopectineal line (early sign) → protrusio acetabuli
PAGET’S DISEASE – OSTEITIS DEFORMANS

36. XR
o LONG BONES:
• Usually starts at end of bone (except tibia: begins in the tuberosity)
• Extends to diaphysis - demarcated from normal bone by aV-shaped zone of transition
(‘flame-shaped’ lysis)
• Increased cortical width
• Weakened bones bowing due to weight bearing
o VERTEBRAE: enlargement of vertebral body with neural arch and pedicle involvement
(distinguishes from metastatic disease)
• ‘Picture frame’ appearance: condensed thickened end plates and vertebral margins
enclosing a cystic spongiosa
• ‘Ivory’ vertebrae: sclerotic vertebral bodies → there can be collapse (cord compression)
PAGET’S DISEASE – OSTEITIS DEFORMANS

37. (A) XR tibia: sharply demarcated lysis along distal
anterior cortex (arrow) of the tibia (‘blade of
grass’ appearance), bony expansion of proximal
tibia with mixed sclerotic and lytic appearance,
indicating advanced disease
(B) XR Forearm: cortical expansion, sclerosis, and
bowing of the radius
PAGET’S DISEASE – OSTEITIS DEFORMANS

38. Gross Paget’s disease of skull
PAGET’S DISEASE – OSTEITIS DEFORMANS
Compression and distortion of
IAM and middle ears secondary to
Paget’s disease of the skull

39. a.‘Picture frame’ appearance in a vertebral body.The pedicles are enlarged.
b. Bone scan demonstrates increased uptake.
PAGET’S DISEASE – OSTEITIS DEFORMANS

40. PAGET’S DISEASE – OSTEITIS
DEFORMANS
Pathognomonic triad of :
• Bone expansion
• Cortical thickening
• Trabecular bone thickening

41. Complication:
• Neoplastic complications are rare but
include sarcomatous transformation to
osteosarcoma, malignant fibrous
histiocytoma/fibrosarcoma,
chondrosarcoma
PAGET’S DISEASE – OSTEITIS
DEFORMANS

42. REFERENCES
1. Clyde A Helms, Fundamental Skeletal Radiology
2. Grainger & Allison’s Diagnostic Radiology
3. Radiologyassistant
4. Radiopaedia