Osteosarcoma is a malignant bone tumor characterized by the production of bone tissue by cancerous cells. It is the most common type of primary bone cancer and often appears as an aggressive lesion in the long bones of teenagers and young adults. Treatment typically involves preoperative chemotherapy followed by wide surgical excision or limb salvage surgery along with additional chemotherapy. Prognosis depends on the presence of metastases, with 5-year survival rates being higher for localized disease compared to metastatic disease.

1. OSTEOSARCOMA
DR. SHAHZAIB RIAZ
SENIOR RESIDENT
ORTHOPEDICS DEPARTMENT
DR. ZIAUDDIN UNIVERSITY HOSPITAL
KARACHI

2. INTRODUCTION
• Osteosarcoma is a tumor characterized by the production of osteoid
by malignant cells.
• Second most common primary malignant tumor of bone
• 20% of primary bone cancers
• Most common nonhematologic primary malignancy of bone
• Incidence
• 1: 3 per 1 million per year

3. • Most common appearance is that of an aggressive lesion in the
metaphysis of a long bone
• 10% are primarily diaphyseal
• 1% are primarily epiphyseal
• Lesion can be either predominantly blastic or predominantly lytic
• The lesion usually is quite permeative
• Borders are ill defined
• Soft-tissue mass may be present at the time of diagnosis
• Periosteal reaction may take the form of a
• Codman triangle
• Sunburst or
• Hair-on-end appearance.

4. Magnetic resonance imaging
• Best imaging modality to measure the extent of the tumor within the
bone
• Extent in the soft tissue
• Relationship of the tumor to nearby anatomic structures.

5. BONE SCAN
• should be obtained to look for skeletal metastases
• CT of the CHEST should be done to search for pulmonary metastases
• lungs are the most common sites of metastases.

6. CLASSIFICATION OF OSTEOSARCOMA
• Primary Osteosarcoma
• Conventional Osteosarcoma
• Low-grade Intramedullary Osteosarcoma
• Parosteal Osteosarcoma
• Periosteal Osteosarcoma
• High-grade Surface Osteosarcoma
• Telangiectatic Osteosarcoma
• Small Cell Osteosarcoma
• Secondary Osteosarcoma

7. • Intramedullary osteosarcoma is the most common primary sarcoma
• Most common malignancy of bone is metastatic disease
• Most common primary malignancy of bone is myeloma
• Most common site is the distal femur and proximal tibia
Other sites (proximal humerus, proximal femur, and pelvis)
Age & location
• Children and young adults
• Bimodal distribution of occurrence
Majority occur in the second decade of life
Second peak in occurrence is in elderly patients with paget's disease
INTRAMEDULLARY OSTEOSARCOMA

8. • 10-20% of patients present with
pulmonary metastases (obtain
CT of chest)
• lung is most common site of
metastasis
• bone is second most common site
• Genetics
• Patients with Rothmund Thomson
syndrome and Retinoblastoma

10. TREATMENT
MULTI-AGENT CHEMOTHERAPY AND LIMB SALVAGE RESECTION
• Chemotherapy
 Preoperative chemotherapy given for 8-12 weeks followed by maintenance
chemotherapy for 6-12 months after surgical resection
 98% necrosis after neoadjuvant = good prognosis
 Expression of multi-drug resistance (MDR) gene tends to have a poor
prognosis
• Trend towards limb salvage whenever possible
• Rotationplasty is a great surgical option which optimizes the patient's
function, and most commonly done in a pediatric population

11. ROTATIONPLASTY

13. WIDE SURGICAL RESECTION
• indicated in low grade osteosarcoma
AMPUTATION
• pathologic fracture
• encasing neurovascular bundle
• enlarging during preop chemo AND adjacent to neurovascular bundle

14. LOW-GRADE INTRAMEDULLARY OSTEOSARCOMA
• Rare type
• Indolent course with relatively benign features on radiograph
• Can be mistaken radiographically and histologically for an
• Osteoblastoma
• Fibrous dysplasia
• Intramedullary location
• Microscopically
• It consists of slightly atypical spindle cells producing slightly irregular osseous
trabeculae.
• Treatment
 Wide surgical resection

15. PERIOSTEAL OSTEOSARCOMA
• An intermediate grade malignancy that arises on the surface of the
bone
• Most common locations are the diaphyses of the femur and tibia
• Usually in patients from 15 to 25 years
• More common in females
• Histological:
• Strands of osteoid-producing spindle cells radiating between lobules of
cartilage

16. RADIOGRAPHS
• lesion has a classic "sunburst"
or "hair on end" periosteal
reaction
• often sunburst periosteal
reaction occurs in a
“saucerized” cortical
depression
• typically there is no
involvement of the medullary
canal

17. • Grossly tumor
appears lobular
and cartilaginous
• Tumor produces
osteoid
• Histology reveals
areas of
chondrolblastic
matrix

18. PERIOSTEAL OSTEOSARCOMA

19. Specimen After Wide Resection

21. TREATMENT
OPERATIVE (SAME AS INTRAMEDULLARY OSTEOSARCOMA)
• MULTI-AGENT CHEMOTHERAPY AND LIMB SALVAGE RESECTION
• standard of care in most patients
• CHEMOTHERAPY
• preoperative chemotherapy given for 8-12 weeks followed by
maintenance chemotherapy for 6-12 months after surgical resection
• SURGICAL RESECTION
• limb salvage whenever possible

22. PAROSTEAL OSTEOSARCOMA
• Rare, low grade malignancy
• more common in females, age 30-40
• Arises on the surface of the bone and
• Invades the medullary cavity only at a late stage
• Most common sites include posterior distal Femur, proximal Tibia,
and proximal Humerus
• 80% cases occur in the Femur
• Peculiar tendency to occur as a lobulated ossified mass on the
POSTERIOR ASPECT OF THE DISTAL FEMUR

23. Presentation
• often presents as a painless mass
• limited joint motion can also be a presenting complaint
for characteristic large posterior distal femoral lesions
CT Scan helpful
• Differentiating this subtype of osteosarcoma from
myositis ossificans or an osteochondroma.
• Ossification in myositis ossificans is more mature at the
periphery of the lesion, whereas the center of a parosteal
osteosarcoma is more heavily ossified

24. Prognosis
• 95% long term survival when local control has been achieved
• Dedifferentiation of parosteal osteosarcoma is a poor prognostic
factor
• Invasion into the medullary cavity does not affect long-term
survival

25. RADIOGRAPHS AND CT SCAN OF A PAROSTEAL OSTEOSARCOMA

26. MR Image Shows The Lesion Arising From Posterior Surface Of Distal Femur
Without Involvement Of Marrow Cavity
Typical Microscopic Appearance Of Parosteal Osteosarcoma.
Slightly Atypical Spindle Cells Produce Relatively Normal-appearing Trabeculae

27. TREATMENT
WIDE LOCAL SURGICAL EXCISION
 Standard of care in most patients
 Many consider geometric osteotomy of involved bone to
decrease long term morbidity and retain native joint
 Chemotherapy not indicated unless there is a high grade
component
 Outcomes
• Often curative

28. High-grade surface osteosarcoma
• least common
• Aggressive tumor arising on the outer aspect of the cortex
• Radiographs
• invasive lesion with ill-defined borders
• Microscopically
• high-grade tumor with hypercellularity, mitotic figures, and marked nuclear
pleomorphism

29. TELANGIECTATIC OSTEOSARCOMA
• A malignant osteogenic tumor
• Purely lytic lesion
• Ballooned appearance similar to that of an ABC.
• Blood-filled cyst with only a very small solid portion.
• Rare (4% of osteosarcomas)
• Male > female
• Location:
• proximal humerus, proximal femur, distal femur, proximal tibia
• occur in same location as ABC

32. • Low power microscope
• Commonly resembles an aneurysmal bone cyst with
blood-filled spaces separated by thin septa.
• Higher-power magnification
• The cells in the septa appear frankly malignant.

33. HISTOLOGY
• High grade sarcoma with mitotic figures is seen
in intervening cellular areas
• Lakes of blood mixed with malignant cells (not
in ABC)
• Not as much osteoid as intramedullary
osteosarcoma
• Histology is critical to differentiate from ABC

34. PROGNOSIS
• Poor Prognostic Signs
• advanced tumor stage is most important indicator
• Increased lactate dehydrogenase (LDH) and alkaline
phosphatase (ALP)
• expression of multi-drug resistance (MDR) gene
• pathologic fractures increased risk of recurrence
• Favourable Signs
• 98% necrosis with chemo is good prognostic sign

35. Survival
• More chemosensitive but same survival as
intramedullary osteosarcoma
• 5 year survival with tumor localized to an extremity
is ~70%
• 5 year survival with metastases is ~20%

36. TREATMENT
• MULTI-AGENT (NEOADJUVANT) CHEMOTHERAPY AND
LIMB SALVAGE RESECTION
• Standard of care in most patients
Surgical resection
• Trend towards limb salvage whenever possible
• Can be performed in close to 90% of cases
• Outcomes
• Risk of recurrence is decreased with good cellular response/wide surgical
margins

37. Small cell osteosarcoma
• Rare variant
• Highgrade lesion that consists of small blue cells
• May resemble Ewing sarcoma or lymphoma
• Cytogenetic and immunohistochemistry studies sometimes are
needed to differentiate these lesions

38. SECONDARY OSTEOSARCOMAS
• Rarely occur in young patients
• Constitute almost half of the osteosarcomas in patients older than
age 50 years.
• Example:
• Paget disease
• Previous radiation therapy
• Incidence in paget disease is approx 1% and may be higher (5% to
10%) for patients with advanced polyostotic disease
• Age: 6th to 8th decade of life
• Location: pelvis (most common)

39. • Radiation-associated osteosarcoma occurs in approximately 1%
greater than 2500 cGy
• can occur in unusual locations, such as the skull, spine, clavicle, ribs,
scapula, and pelvis
• Although osteosarcoma is the most common radiation associated
sarcoma, fibrosarcoma and malignant fibrous histiocytoma also are
relatively common in this setting
• The time to onset of the secondary osteosarcoma averages 10 to 15
years after radiation exposure but may occur 3 years to several
decades after treatment

40. SUMMARY
OSTEOSARCOMA

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