This document provides an overview of the approach to orthopedic oncology. It begins with an introduction and outlines the classification, clinical presentation, staging, and types of primary bone tumors. Bone tumors are classified based on the dominant tissue and can be benign or malignant. Clinical evaluation involves history, physical exam, imaging, and biopsy. Staging uses the Enneking system to describe the grade, site, and presence of metastases. Primary bone tumors discussed include benign entities like osteoid osteoma and giant cell tumor as well as malignant tumors such as osteosarcoma, Ewing's sarcoma, and chondrosarcoma. Treatment depends on the tumor type, location, and stage.
3. A bone tumor is an abnormal growth of
cells within a bone.
The definate cause of bone tumors is
unknown.
Possible causes include:
1.Genetic defects passed down
through families
2.Radiation
3.Injury
They often occur in areas of rapid bone
growth.
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4. Cancers that start in the bones are
referred to as primary bone tumors.
Cancers that start in another part of the
body (such as the breast, lungs, or colon)
are called secondary or metastatic bone
tumors.
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5. Classification of Bone tumors
Most classifications of bone tumors are
based on the dominant tissue in the
various lesions.
8. History
History is often prolonged, results in delay
of treatment.
Patients most of the time will be
completely asymptomatic until the
abnormality is discovered on X-ray.
This is more of benign lesions, common in
children and rare after 30
Malignant tumors can be silent if they are
slow growing and there is room for
expansion like cavity of the pelvis.
9. AGE
A Useful clue.
Many benign tumors present during
childhood and adolescence
Chondrosarcoma and fibrosarcoma
typically occur in 4th and 6th decades
adults.
Myeloma rarely seen before 6th decade.
Patients over 70 years metastatic bone
lesions are more common than primary
tumors.
10. PAIN
common complaint and gives little
indication of the nature of lesion.
Progressive and unremitting pain is a very
important symptom though.
It may be caused by:
1. Rapid expansion
2. Central hemorrhage or degeneration of
the tumor
3. Pathological fracture.
11. Pathological fracture
may be the first and only clinical sign.
In elderly people whose bones usually
fracture at the cortico-cancellous
junctions, if they get mid shaft fracture
it is regarded as pathological until
proven otherwise.
12. Other presentations
Swelling:
Appearance of a lump, may be alarming.
Neurological symptoms:
Parasthesia and numbness may be caused
by pressure or stretching of a peripheral
nerve.
Progressive dysfunction is alarming and
suggests invasion by an aggressive tumor.
13. Examination
If there is a lump: Where does it arise?
Is it well defined or not?
Soft, hard or pulsatile?
Tender?
Swelling can be diffuse and the overlying
skin warm and inflamed which makes it
hard to distinguish from infection and
hematoma.
14. If it is near a joint:
is there any movement limitation?
Spinal lesions cause muscle spasm, back
stiffness or painful scoliosis.
Examination will focus on symptomatic part
but it should include :
lymph nodes
pelvis
abdomen
chest and spine.
15. Imaging
X-ray:
it’s not useless imaging technique..
There might be obvious abnormality of the
bone:
1. Cortical thickening
2. Discrete lump
3. Cyst
4. Ill-defined destruction
16. Is it in the metaphysis or diaphysis?
Is it solitary or multiple lesions?
Margins are well or ill defined?
Note: cystic lesions are not necessarily
hollow cavities: any radiolucent material
may look like a cyst (e.g fibroma and
chondroma)
17. If the boundaries of the cyst is well defined is
mostly benign.
If it is hazy and diffuse it is mostly invasive tumor.
Bone surfaces: periosteal new bone formation
and extension of the tumor to the soft tissues
are suggestive of a malignant tumor.
18. Soft tissues:
are the muscle planes distorted by the
swelling?
Is there any calcification?
X-ray is not a definitive diagnosis and further
investigation must be done to confirm.
19.
20. Other techniques of imaging used are :
Radionuclide scanning
CT
MRI
They all help in viewing the lesions better, view
soft tissue and detect skip lesions too.
Patient must not go for biopsy if MRI or CT is
planned for him as it will distort the image and
appearances.
21. Biopsy
There are three ways:
1.Needle biopsy:
Must be performed by experienced personal.
2. Open biopsy:
most reliable way of obtaining a representative
sample.
3. Excisional biopsy: for benign tumors.
26. Staging of bone tumors
Staging is the process of finding out how
far the cancer may have spread.
This is very important because the type of
treatment and the outlook for recovery
(prognosis) depend on the stage of the
cancer.
27. In treating tumors we are facing two conflicting
principles:
1. Lesion must be removed widely to ensure it
doesn’t recur.
2. Damage must be kept minimal.
28. The balance between the 2 conflicting objectives
depends on knowing:
1. How the tumor behaves (Aggressiveness)
2. How far it has spread.
The answers to these two questions are embodied in
the staging system of Enneking.
30. Enneking Staging system
Benign Tumors
Latent Well defined margin. Grows slowly and then stops.
Remains static/heals spontaneously E.g Osteoid
osteoma
Active Progressive growth limited by natural barriers.
Not self limiting. Tendency to recur E.g Aneurysmal
Bone cyst
Aggressive Growth not limited by natural Barriers E.g Gaint cell
tumor
31. Malignant Tumors
Low Grade Moderately aggressive and takes a long time to
metastasize
High Grade Very aggressive and metastasize early
32. Spread
Assuming that there is no metastases, the
local extent of the tumor is the most
important factor in deciding how much
tissue to be removed.
Spread
Intra-
compartmental
Extra-
compartmental
33. Spread
Lesions that are confined to an enclosed
space (e.g Bone cavity, joint cavity or
muscle group within its fascial envelope)
are called Intra-compartmental.
Lesions that extend into inter-fascial or
extra-fascial with no natural barrier to
proximal or distal spread are called Extra-
compartmental. (E.g pelvis, axilla)
34. Surgical stage
Staging the tumor is an important step towards
selecting the best operation suited to the
patient.
Bone sarcomas are divided as follows:
1. Stage 1: All low grade sarcomas
2. Stage 2: Histologically high grade lesions
3. Stage 3: Sarcomas which have metastasized.
35. Surgical stages described by Enneking
Stage Grade Site Metastases
IA Low Intracompartmental No
IB Low Extracompartmental No
IIA High Intracompartmental No
IIB High Extracompartmental No
IIIA Low Yes
IIIB High Yes
39. Osteoid Osteoma
peak incidence in 2nd and 3rd decades,
M:F = 3:1
small, round radiolucent nidus (<1 cm) surrounded
by dense bone
tibia and femur most common
produces severe intermittent pain, mostly at night
characteristically relieved by NSAIDs
41. Osteochondroma
2nd and 3rd decades, M:F = 1.8:1
metaphysis of long bone
cartilage-capped bony spur on surface of bone
may be multiple
higher risk of malignant change
generally asymptomatic unless impinging on
neurovascular structure
malignant degeneration occurs in 1-2%
42. Enchondroma
2nd and 3rd decades
50% occur in the small tubular bones of the hand
and foot; others in femur, humerus, ribs
benign cartilaginous growth, develops in
medullary cavity
single/multiple enlarged rarefied areas in tubular
bones
lytic lesion with sharp margination and central
calcification
malignant degeneration occurs in 1-2%
44. Cystic lesions
Include
unicameral/solitary bone cyst (most common),
fibrous cortical defect
children and young adults
local pain, pathological fracture or incidental
detection
lytic translucent area on metaphyseal side of
growth plate
cortex thinned/expanded; well defined lesion
treatment of unicameral bone cyst with steroid
injections ± bone graft
45. treatment only necessary if symptomatic
osteochondroma: resection
cystic lesions: curettage and bone graft
52. Chondrosarcoma
primary
previous normal bone, patient over 40; expands into
cortex to give pain, pathological fracture, flecks of
calcification
secondary
malignant degeneration of pre-existing cartilage
tumour such as enchondroma or osteochondroma
most commonly occurs in pelvis, femur, ribs,
scapula, humerus
unresponsive to chemotherapy, treat with
aggressive surgical resection + reconstruction
54. Ewing’s sarcoma
most occur between 5-20 years old
florid periosteal reaction in diaphysis of long bone
moth-eaten appearance with periosteal lamellated
pattern (onion-skinning)
present with mild fever, anemia, leukocytosis
and increased ESR
metastases frequent without treatment
treatment “ resection, chemotherapy, radiation
survival “ 70%
55. Multiple myeloma
most common primary malignant tumour of bone
in adults
90% occur in people >40 years old
present with anemia, anorexia, renal failure,
nephritis, increased ESR, bone pain, compression
fractures, hypercalcemia
diagnosis
punched-out lytic lesions on x-ray at multiple bony
sites
serum/urine protein electrophoresis
treatment: chemotherapy, radiation, surgery for
symptomatic lesions or impending fractures
56.
57. References
Medline plus: Service of U.S national Library of
Medicine
http://www.nlm.nih.gov/medlineplus/ency/article/00
1230.htm
Apley’s system of orthopedics and fractures (Ninth
Edition)
Apley’s Concise system of orthopedics and fractures
(Third Edition)
American Cancer society
http://www.cancer.org/Cancer/BoneCancer/Overvi
ewGuide/bone-cancer-overview-staging
First Aid for the USMLE Step 1 2011
Toronto notes 2009