2. • Thesignificance of the tumor-like bonylesions
is that their appearance may mimic of
malignant bone tumors, which gives rise to
differential diagnostic problems, since they
are much more common.
• Some tumor like lesions of bones are..
3. Simple bone cyst
Also known as
Unicameral Bone Cyst.
They Are entirely
benign lesion of
unknown aetiology.
They are always
unilocular.
4. AGE
• Childhood and early adolescense
• Before the epiphyseal fusion occur.
• In adults, some lesions occur after skeletal
maturation in such bones as the Calcaneus
and Talus
7. ClinicalFeatures
Asymptomatic and found incidentally.
Only a few produce minor
discomfort. May be pain, swelling
and stiffness of adjacent joint.
More than half present due to a
pathological fracture
10. Fallen fragment sign
If there is fracture
through this lesion,
a dependent bony
fragment may be
seen, and this is
known asthe fallen
fragment sign.
13. Differential diagnosis
1. Fibrous dysplasia
2. Aneurysmal bone cyst
3. Non ossifying fibroma
Non-ossifying fibroma- eccentric
and cortical based.
14. Simple bone
cyst
Aneurysmal bone cyst
Site Metadiaphysis Typically in the metaphysis
Bone scan No abnormality
develops
Rich increase in vessels and early
venous filling
CT & MRI
(fluid-fluid
levels)
Absent Are the characteristic
Association Absent May be with non-ossifying
fibroma, fibrous dysplasiaand
chondromyxoid fibroma
Cyst Clear liquid and
always
unilocular
Contains blood with giantcells
and multilocular.
15. Simple bone cyst Fibrous dysplasia
Sites Proximal humerus
Proximal femur
Other long bones
Calcaneus
Commonly pelvis, femur, ribs. Often
skull
Plain film An area of
translucency.
Centrally in the
metadiaphysis.
Lesions may be lucent, dense or a
mixture with small flecks of density
due to ossification
Pathology Cyst filled with
clear fluid
Medullary bone is replaced by well
defined area of fibrous tissue and cysts
containing blood or serous fluid
Endocrine
complications
Absent May be associated with-
Skin pigmentation,precocious puberty,
acromegaly, hyperthyroidism, cushings
syndrome.
16. Aneurysmal bone cyst
• An aneurysmal
bone cyst is a
benign, expansile
lesion with blood
filled cavities
separated by
septa of
trabecular bone
or fibrous tissue
containing
osteoclast giant
cells.
17. • Incidence and Demographics.
ABCcanfound at anyage
Around 75%:before20years.
Female:Male =2:1
Site- canbe found in anybone in the body. The
most common location isthe metaphysisoflong
bones of lower extremity.
18. PRESENTATION
Patients usually present with pain, a mass, a
pathologic fracture, or combination of
these symptoms in the
affected area.
19. X-Ray Appearance
• ABC is normally placed in the metaphysis and appears
as a osteolytic lesion. The periosteum is elevated and
the cortex is eroded to a thin margin.
• The expansile nature of the lesion is often
reflected by a
"blown-out" or "soap bubble" appearance.
20.
21. CT scanof aneurysmal
bone
cyst arising
from
lamina and
internal
mass of
C6 resulting
in a unilateral
dislocation of the facet
joints in a 10 year old
girl.
22. The MRI showed C2spinous
process osteolytic
lesion(ABC), fluid-fluid levels .
23. Differential Diagnosis
• Simple bonecyst
• Giantcelltumor of bone
-occurs in patients over age 20 -40 year, when
growth plate fuses.
-expansile, eccentric, wide zone of transition
-involves joints or adjacent bone or soft
tissue, show more aggressive nature.
24. • Osteoblastoma
-may have a “soap bubble” expansile
appearance
• no fluid-fluid level on CT/MR
-Fibrous dysplasia-ground-glass opacities: 56%
-no periosteal reaction
25. NON OSSIFYINGFIBROMA
• It is anon-neoplastic
process, possibly
related to defect in
ossification.
• Classically involves
metaphysis .
• Typically lesion is
solitary, radiolucent,
eccentric and
generally ovoid and
have sclerotic
magins.
26. • Sites- Distal femur, proximal and distal tibia.
• Asymptomatic and are discovered incidentally.
27. • Xray-
• Eccentric,lytic
lesion centered
within the
metaphysealcortex
andadjacent
medullary cavityof
long tubular bones.
• Well demarcated
with sclerotic
marginswith
internal
trabeculations.
28. Fibrous dysplasia
• . In FD there is replacement of the normal
lamellarcancellous bone by abnormal fibrous
tissue.
• Defect in Osteoblast differntiation &maturation.
• Females > Males
• Age group- 3-15 yrs (Initial Manifestation)
• GNAS1 Mutation
30. Natural history
• Polystotic FD is more aggressivethan
monostotic FD.
• Thelesions usually progress in number till the
end of skeletal maturation, by then they
become quiescent
• In only about 5%of casesit continueto
enlarge after that.
31. HOWITLOOKSONXRAY
• Geographical lytic lesions in
medullary canal (diaphysis or
metaphysis)
• May havecortical thinning
with expansilelesion.
• Highly lytic lesions or aground
glassappearance may be
seen.
33. Shepherd's crookdeformity
• Coxavarus angulation of the proximal femur,
classically seenin femoral involvement by fibrous
dysplasia, although may be seenin other disorders
suchasPagetdiseseof bone and osteogenesis
imperfecta.
UMY
38. Myositis ossificans
• congenital
progressive disease
in which groups of
tendons and
muscle, usually
around major
joints, become
progressively
calcified and
ossified, producing
severe functional
disability.
39. • Patients present with lump ismuscle.
• History of trauma in only half of the patients.
• Common locations- flexor muscles of the upperarm,
quadriceps femoris, adductor muscle of the thigh,
gluteal muscles and soft tissues of thehand.
40.
41. Differential diagnosis
• osteosarcoma.
• Myositis ossificans is most mature at its periphery
and least mature at its center, the opposite is true
for asoft tissue osteosarcoma.
42. Bone infarct
Bone infarction is a term used to refer
to osteonecrosis within the metaphysis or diaphysis of a
bone.
43. causes
General causes of osteonecrosis include:
•trauma
•caisson disease
•hemoglobinopathies, e.g. sickle cell disease
•radiotherapy
•connective tissue disorders
•renal transplantation
•corticosteroids
44. Radiographic features
General features include:
location
medullary
metaphyseal
serpiginous border
often symmetrical ,can be multiple
Differential diagnosis
enchondroma: chondroid matrix, central marrow
signal is absent
healing non-ossifying fibroma
46. Intraosseous lipoma
The radiographic
appearance of
intraosseous
lipomas -It may be
typically seen as
osteolytic bone
lesion with well-
defined margins.
Central calcification
may develop
creating the cockade
sign.
