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Welcome……………
METASTATIC BONE TUMOURS.
Dr Raviteja Athkuri
METASTATIC BONE TUMOURS
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.
Overview of Common Malignant Bone Lesions
M.M mc LYTIC 75% BLASTIC15% MIXED 10%
O.S 2mc LUNG PROSTATE PROSTATE
C.S 3mc BREAST BREAST BREAST
EW.S 4 mc
Primary 30%Secondary 70%
Most Common Causes for Osseous Metastasespopulation lytic blastic
Female Breast 80% Breast 10%
Male Lung 75% Prostate 80%
Young < 20 yrs
NB 80% Hodgkin s 50%
Features of bone mets. 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
Events in development of mets 1.Capable of autonomous survival
after liberation.
2.Pathway of dissemination must be available.
3.Proper environment for growth of implant at new site.
Spread of cancer from one part of the body to another
Path ways 1.direct
2.lymphatic,
3.hematogenous.
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,
Lymphatic Dissemination.
Uncommonly play a role in spreading tumor emboli to bone.
Due to absence of lymphatic channels.
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.
VERTEBRAL VEIN SYSTEM (BATSON’S VENOUS PLEXUS)
. 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.
Types ------ Lytic lesions,
------Blasic lesion,
------- Mixed lesions.
General radiological features of Metastatic Carcinoma to Bone
Axial skeleton predilection.
Multiple sites
DISTRIBUTION OF SKELETAL METASTASES.
Lytic Destruction
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.
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.
Osteolytic metastases (75%) Cortical and trabecular
destruction,
Lack of periosteal response,
Moth-eaten, permeative destruction,
Small or absent soft tissue mass,
Multiple sites,
Variants (lung, thyroid, kidney);
solitary expansile ( soap bubble
lesion)
Blastic Metastases.
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.
Osteoblastic metastases (15%) Localized or diffuse
increased bone density,
Poorly defined margins,
Multiple sites,
Mixed metastases (10%)
Combination of blastic and lytic features
Nuclear Imaging (Bone Scans). 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.
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 .
MRI appearence
Metastatic deposits contains more water.
Mri appearence 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
BENIGN CONDITIONS.
positive bone scans Paget’s disease, fibrous dysplasia, fractures, osteomyelitis, osteoid osteoma, osteoblastoma, arthritides, and ischemic necrosis.
Benign Conditions Simulating Osseous Metastatic CancerOsteolytic Osteoblastic
NF MelorheostosisEnchondromatosis OsteopoikilosisPoly ostotic FD Osteopathia striataBrown tumours OsteopetrosisGout PagetsOM SarcoidosisGorhams angiomatosis TS,
Chr.OMSCAMastocytosisFlurosis
Fact ……… nearly 50% pts with spinal metastases present
at autopsy, the lesions were not detectable in premortem tomograms.
Primary organ of involvement
Lytic % Mixed % Blastic %
breast 80 10 10Lung 75 20 5Renal 80 10 10Thyroid 90 10 -----Salivary glands
100
Blow-Out Metastatic Lesions 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.
Differentiating Radiologic Features between Primary and SecondaryLesionsFeature Primary Secondary
Incidence30% 70%
Expansion of bone ++++ +Joint invovement ______________________
________________________
Length of lesion >6 cm 2-4cmPeri osteal response +++ +Solitory lesion +++ +Multiple lesions + +++Soft tissue mass. +++ +
Specific anatomical locations. Spine---- vertebra, Pedicle, Pelvis , Ribs and sternum, Acral ends , Extremities.
Spine
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.
Vertebra
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.
Solitory vertebral collapseMC causesMets.ca ChordomaMyloma (plasma cytoma) HemangiomaEosinophillic granuloma Hydatid cystTraumatic fracture Ewing sarcomaPagets O SInfectionSteroid abuse,cushing disease
G C T
Malig.lymphoma
Pedicle
Any component of post.neural acrch.
Pedicle………..m.c
One eyed pedicle sign/winking owel sign.
Blind vertebra.
At a glance…..
Location …L/T body/pedicles, Signs ……… metabolic bone density dec…moth
eaen/permeative/diffuse incr….localised/ivory
Cortical destruction. Disc space uneffected.
Pathological collapse… decr. Post.V. height., end plate disruption (malig. Schmorl
node)
Pedicle destruction One eyed pedicle
sign, blind vertebra,
DD for pedicle destruction Congenital……agenesis/hypoplasia Neoplasams beningn……ABC OB NFoma OO Malignant……lytic mets myloma.
Ivory vertebra
Osteoblastic metastatic carcinoma,
three most common causes
Prostate
/pagets/H.lymphoma,
Factor Blastic mets Pagets Hodgkin
Age >45 >50 20-40
Incr.density +++ +++ +++
Expansion +++
Anterior scalloping
+++
Acid phasphatase
+++
Alk.phosphatase
++ +++ ++
Solitary ivory vertebraCommon causes Un common causes
OB mets SarcoidosisHD lymphoma ChordomaPaget s MyelomaDegenerative sclerosis OsteosarcomaOM Ewings Idiopathic OO
OBBone island
Pelvis
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,
Skull
10% of met.lesions….. , Lytic mets………….m.c 90%
breast,prostate,thyroid.
Blastic mets…….10% carcinoid
DD….
1.Multiple myloma…
- permeative lytic
-all are in uniform
size.2.mets… lytic with
varying sizes.
Ribs and sternum
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
Acral mets 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.)
Periosteal reaction Very rare,in the
absence of path.#
Adults………..prostate ,lung ,breast.
Children………neuroblastoma.
Bone invol..preceeds than periosteal invol.
Rarely
Bone Expansion and Soft Tissue Mass can be seen.
COMPLICATIONS
Pain ,pathological #,
>50% cortical bone destruction is needed.
Collapse of vertebra,
Extra dural compression of cord,
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..
THANK YOU……
Thank you……..