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.

1. Approach
To
Orthopedic
Oncology

2. OUTLINE
Introduction
Classification of Bone tumors
Clinical Presentation
Staging of Bone tumors
Primary Bone tumors
Case Presentation

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.
Medline plus: Service of U.S national Library of Medicine
http://www.nlm.nih.gov/medlineplus/ency/article/001230.htm

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.
Medline plus: Service of U.S national Library of Medicine
http://www.nlm.nih.gov/medlineplus/ency/article/001230.htm

5. Classification of Bone tumors
 Most classifications of bone tumors are
based on the dominant tissue in the
various lesions.

6. Classification of Bone tumors

7. Clinical presentation
 History
 Examination
 Imaging
 Biopsy
 Important differential diagnosis

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.

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.

22. Deferential Diagnosis

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.

29. Tumor
Benign
Latent Active Aggressive
Malignant
Low Grade
High
Grade
Aggressiveness

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

36. Management

37. Primary bone tumors
Divided into Benign and Malignant.
They are rare to occur and secondary
bone tumors are more common.

38. Osteoid Osteoma
Giant cell Tumor
Enchondroma
Benign Tumors

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

40. Osteoid Osteoma

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%

43. Enchondroma

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

46. Cystic lesions

47. Giant cell Tumor
 affects patients of skeletal maturity, peak 3rd decade
 distal femur, proximal tibia, distal radius, sacrum, tarsal
bones, spinal (osteoblastoma)
 cortex appears thinned, expanded; well-demarcated
sclerotic margin
 local tenderness and swelling
 aggressively destroy bone
 15% recur within 2 years of surgery
 giant cell tumour occasionally metastasizes (1-2%)
 Treatment
 intralesional curettage + bone graft or cement
 wide local excision of expendable bones

48. Giant cell tumor

49. Malignant tumors
Multiple myeloma
Osteosarcoma
Ewing’s sarcoma
Chondrosarcoma

50. Osteosarcoma
 mostly frequently diagnosed in 2nd decade of life (60%)
 Mostly affects distal femur (45%), proximal tibia (20%)
and proximal humerus (15%)
 invasive, variable histology; frequent metastases without
treatment
 painful, poorly defined swelling
 x-ray shows
 characteristic periosteal elevation and spicule formation
representing tumour extension into periosteum
 treatment: complete resection (limb salvage, rarely
amputation), chemotherapy
 survival “ 70%

51. Osteosarcoma

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

53. Chondrosarcoma

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

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