This document summarizes malignant bone tumors and bone metastases. It discusses that 70% of malignant bone tumors are metastases from a primary cancer elsewhere, with 30% being primary bone cancers. The most common primary sites that metastasize to bone are lung, prostate, and breast cancers. Bone metastases can be lytic, blastic, or mixed based on whether they cause bone destruction, formation, or a combination. The most common pathways for metastases to reach bone are through the bloodstream via the venous system, especially the Batson's plexus which connects the pelvis and spine. Common symptoms are pain and pathological fractures. Imaging plays an important role in evaluating bone lesions and distinguishing between benign versus malignant etiologies.

6.  M.c malignant tumours of skeleton.
 Malignant tumours of bone
70% - mets in origin
30%- primary
 Almost all tumours metastasize to bone
except 1.BC carinoma of skin,
2.CNS tumours.

7. M.M mc LYTIC 75% BLASTIC15% MIXED 10%
O.S 2mc LUNG PROSTATE PROSTATE
C.S 3mc BREAST BREAST BREAST
EW.S 4 mc

8. population lytic blastic
Female Breast 80% Breast 10%
Male Lung 75% Prostate 80%
Young < 20 yrs NB 80% Hodgkin s 50%

9.  4 th decade.
 <5 yr…….NB,
 10-20 yrs……EW.,OS,
 20-35 yrs……HD.lymphoma.
 Principle sign and symptoms..pain,path.#,
 Nonspecific ESR,
alk.phospatase- blastic
s.ca -lytic

10.  1.Capable of autonomous survival after
liberation.
 2.Pathway of dissemination must be
available.
 3.Proper environment for growth of implant
at new site.

11.  Path ways
1.direct
2.lymphatic,
3.hematogenous.

12. Direct pathway.
 From a soft tissue tumor lying
adjacent to or near the bone.
 Example …Carcinoma of the
uterus is well known to cause
direct extension to the iliac
bones.
 Mechanical transport of tumor
cells by instruments or gloves
during surgery,
 Less common pathway of direct
transplantation is the seeding of
tumor along one of the natural
pathways in the body,

13.  Lymphatic Dissemination.
 Uncommonly play a role in spreading tumor
emboli to bone.
 Due to absence of lymphatic channels.

14.  Hematogenous Dissemination.
 Particularly the veins, is the most common pathway for tumor
emboli.
 Venous network is a common two-way avenue of metastatic
spread of pelvic, abdominal, and thoracic tumors.
 arteries are thick walled and often resist tumor penetration.
 Three areas most commonly seeded in this manner are the
lungs, liver, and axial skeleton.

15. .
 Batson’s plexus provides a series
of venous passageways by which
cancer cells can be directly
seeded into the bones,
bypassing the liver and lungs
 blood flow is sluggish and
subject to arrest and even
reversal.
 Changes in intra-abdominal or
intra thoracic pressure may tend
to reflux blood flow in the
direction of the paravertebral
plexus.

16.  Types
------ Lytic lesions,
------Blasic lesion,
------- Mixed lesions.

17.  Axial skeleton predilection.
 Multiple sites

19.  Destruction must occur in the medullary canal before a
perceptible alteration of bone density.
 Pressure from the proliferating neoplasm on the
surrounding trabecular structures and cortices that
creates the so-called osteolytic lesion.
 At least 30% loss of bone density is necessary before
detection
 Osteoclasts play little if any role.

20.  majority of metastatic lesions begin within the medullary
cavity and secondarily destroy the adjacent cortex.
 Metastasis to the cortex occurs uncommonly and is most
frequently found in association with carcinoma of the lung,
breast, and kidney.

21.  Cortical and trabecular
destruction,
 Lack of periosteal
response,
 Moth-eaten, permeative
destruction,
 Small or absent soft tissue
mass,
 Multiple sites,

22.  Variants (lung, thyroid,
kidney);
 solitary expansile
( soap bubble lesion)

23.  Laying down of new bone,
which is non-neoplastic in
nature
 but is actually a reactive
response of the local
osteoid tissue to the
presence of the tumor.

24.  Localized or diffuse
increased bone density,
 Poorly defined margins,
 Multiple sites,

25.  Combination of blastic
and lytic features

26.  alterations of as little as 3-5% in the metabolic activity.
 Technetium-99m-methylene dIphosphonate (99mTc-MDP)
is the agent of choice because
 1. A low radiation dose
 2. Convenient half-life for clinical use
 3. Monoenergetic 140-keV photon,
 4 Ideal for current imaging devices.

27.  Taken up and concentrated
in regions of high
metabolic activity in bone.
 Metastases result in a
marked increase in osteoid
production and a
disproportionate increase
in immature woven bone
and, therefore, cause a hot
spot on bone scans .

28.  Metastatic deposits
contains more water.

29.  Focal lytic lesion…..usual
T1-hypo (surroundinf fat)
T2/STIR- hyper
 Focal sclerotic ( MB,RB)
T1,T2…hypo (bone
forming)
 Diffuse heterogenous lesions..NB
T1…inhomog.hypo
T2…hyper
 Diffuse homogenous lesions
T1…homog.hypo
T2…hyper

30.  positive bone scans
 Paget’s disease,
 fibrous dysplasia,
 fractures,
 osteomyelitis,
 osteoid osteoma,
 osteoblastoma,
 arthritides,
 and ischemic necrosis.

31. Osteolytic Osteoblastic
NF Melorheostosis
Enchondromatosis Osteopoikilosis
Poly ostotic FD Osteopathia striata
Brown tumours Osteopetrosis
Gout Pagets
OM Sarcoidosis
Gorhams angiomatosis TS,
Chr.OM
SCA
Mastocytosis
Flurosis

32.  nearly 50% pts with spinal metastases present at autopsy,
the lesions were not detectable in premortem tomograms.

33. Primary
organ of
involvemen
t
Lytic % Mixed % Blastic %
breast 80 10 10
Lung 75 20 5
Renal 80 10 10
Thyroid 90 10 -----
Salivary
glands
100

34.  M.c with carcinoma of lung,
thyroid, and kidney.
 Although most metastatic
lesions are multiple, as many
as 10% may be solitary.
 Specific charecterstrics of
solitory lesion …
bubbly,highly
expansile,..renal/thyroid
Solitary plasmacytoma/GCT
may also have same
appearance.

35. Feature Primary Secondary
Incidence
30% 70%
Expansion of bone ++++ +
Joint invovement _______________________ _______________________
Length of lesion >6 cm 2-4cm
Peri osteal response +++ +
Solitory lesion +++ +
Multiple lesions + +++
Soft tissue mass. +++ +

36.  Spine---- vertebra,
Pedicle,
 Pelvis ,
 Ribs and sternum,
 Acral ends ,
 Extremities.

37.  osseous site for
metastasis to spine…m .c,
 40% of all lesions,
 Thoracic and lumbar……..
m.c
 Body , pedicle……m.c,
 Its very difficult solitary
vertebral mets.

39.  earliest and most subtle sign of
osteolytic lesion is focal
osteoporosis/focal radio lucency
of vertebral body.
 Bone scan…..incre.uptake
 MRI….T1…decr.SI,
T2…incr-intemediate.
STIR….incre.SI
 End plate may shows schmorls
nodes due to weakening l/t
disruption.
 Malignant schmorls….disc
herniation into underlying
malignancy.

41. MC causes
Mets.ca Chordoma
Myloma (plasma cytoma) Hemangioma
Eosinophillic granuloma Hydatid cyst
Traumatic fracture Ewing sarcoma
Pagets O S
Infection
Steroid abuse,cushing disease
G CT
Malig.lymphoma

42.  Any component of
post.neural acrch.
 Pedicle………..m.c
 One eyed pedicle
sign/winking owel sign.
 Blind vertebra.

45.  Location …L/T
body/pedicles,
 Signs ………
metabolic bone density
dec…moth eaen/permeative/diffuse
incr….localised/ivory
 Cortical destruction.
 Disc space uneffected.

46.  Pathological collapse…
decr. Post.V. height.,
end plate disruption
(malig. Schmorl node)
 Pedicle destruction
One eyed pedicle sign,
blind vertebra,

47.  Congenital……agenesis/hypoplasia
 Neoplasams
beningn……ABC
OB
NFoma
OO
Malignant……lytic mets
myloma.

48.  Osteoblastic
metastatic carcinoma,
 three most common
causes
Prostate
/pagets/H.lymphoma,

49. Factor Blastic mets Pagets Hodgkin
Age >45 >50 20-40
Incr.density +++ +++ +++
Expansion +++
Anterior
scalloping
+++
Acid phasphatase +++
Alk.phosphatase ++ +++ ++

51. Common causes Un common causes
OB mets Sarcoidosis
HD lymphoma Chordoma
Paget s Myeloma
Degenerative sclerosis Osteosarcoma
OM Ewings
Idiopathic OO
OB
Bone island

52.  sacrum and bones of the
pelvis … .12% of
skeletal mets.
 Batson’s venous plexus
explains this high
incidence,
 Blow-out lesions of renal
and thyroid origin often
affect the bony pelvis,

53.  10% of met.lesions…..
 ,
 Lytic mets………….m.c
90%
breast,prostate,thyroid.
 Blastic mets…….10%
carcinoid

54.  DD….
 1.Multiple myloma…
- permeative lytic
-all are in
uniform size.
2.mets…
lytic with varying
sizes.

55.  28 % of met. bony lesions.
 Ribs > sternum,
 Any portion of rib, any extent
of the rib can involve.
 Permeative holes,path.#
seen.
 Extra pleural sign….m.c
by chest wall mets
blow out lesion of
renal,thyroid

56.  Rarely distal to elbow/knee,
 Foot…………m.c,
usually missed in
skleletal survey,
breast,lung ,kidney,
 Hand……..distal phallanx
usually associated with br.ca
 Not having periosteal
reaction ( dd infe.)

57.  Very rare,in the
absence of path.#
 Adults………..prostate
,lung ,breast.
 Children………neurobla
stoma.
 Bone invol..preceeds
than periosteal invol.

58.  Bone Expansion and SoftTissue Mass can be
seen.

59.  Pain ,pathological #,
 >50% cortical bone destruction is needed.
 Collapse of vertebra,
 Extra dural compression of cord,

60. Well defined ,moderately built, normal statured,four legged
animal…… ………..BLACK COW
Grossly atrophied ,short statured ,horned four legged ………..
ATROPHIED BLACK COW…
Grossly hypertrohied ,gaint ,prominent elongated nose,teeth of
four legged aniaml with skin discolouration…..
GAINT,HYPERTROPID TRUNCATED COW..

61.  Thank you……..