Presented ByDr. Santosh Atreya

MD Resident,Phase-A,BSMMU.

Outline of PresentationWhat is Osteosarcoma?CharacteristicsGross Pathology and Appearance ClassificationClinical PresentationRegional DistributionDiagnosis/RadiologicalShortly about Parosteal, Periostial osteosarcoma Treatment and PrognosisD/D of OsteosarcomaDifference among Osteosarcoma, Osteomyelitis and

Ewing Sarcoma

Osteo=bone/osteoid tissue.Sarcoma=malignant tumour of

connective tissue.An osteosarcoma is the commonest

primary malignant bone tumour. They account for 25 % of all primary bone

tumors.

Age: 10-25 years

In older age groups associated with Pagets disease

Gender: slight male preponderance exists

Incidence

Location Any bone may be involved, rather

more than half located around the knee involving the metadiaphyses of the distal end of femur and proximal end of tibia

Infrequently in pelvis, spineClavicle ribs scapula and small

bones of hands and feet -rare 10% arise in diaphysis

Clinical PresentationPatients usually present

with localised pain or swelling particularly around the knee, occasionally accompanied by a soft-tissue mass or swelling.

Sometimes, the first symptoms are related to pathological fracture.

CharacteristicsIt is histologically pleomorphic. Two diagnostic features are – a)It’s ability to produce osteoid tissue without

necessarily the development of cartilaginous precursor.

b)The presence of abundant alkaline phosphatase histochemically within the tumor cells

Pleomorphic nature of sarcoma

A dominant cell line may modify the appearance.

If osteoblasts predominate, tumour bone formation will result.

Whereas if cells of cartilage origin are present, extensive calcification may be a presenting feature.

Fig:1.Osteosarcoma of the tibia and fibula-predominantly

osteoblastic.Amorphous calcification/ossification is present in the soft tissues

with cortical destruction and a little periosteal new bone

formation.

Fig:2.Osteosarcoma of the distal femur-predominantly

chondroblastic.Note the well-defined soft tissue mass and

radiating spiculation of calcification within it.

Metastasis: It is highly vascular & metastases occurs by hematogenous route to the lung.Any lung lesion arising in a patient with osteosarcoma should be regarded with suspicion. .Later stage metastasis may spread to bone. Skip metastases-5 to 8%. Lymphatic spread is rare.

Fig: Osteosarcoma-metastasis in the lungs presents with a pneumothorax.

Gross pathologyArise from multipotent

mesenchymal cells.

Mixture of osteoid, fibrous, cartilaginous tissue,necrotic, hemorrhagic,cystic areas, destruction of cortex

Arise eccentrically in the medullary cavity with ill defined cortical destruction and soft tissue involvement.

Gross Appearance

Large tumorsGritty & grayish-white in colorHemorrhageCystic degeneration Cortical destructionSpreads – medullary canalSoft tissue masses present

ClassificationA.Primary osteosarcomaB.Secondary osteosarcoma

A.Primary osteosarcoma: According to dominant cell line( Histopathology) classified as-a. Osteoblasticb. Chondroblasticc. Fibroblasticd. Anaplastic and e.Telangiectatic Accoarding to site:a.Diaphysealb.Centralc.Multifocal and d.Soft tissue osteosarcoma

B.Secondary osteosarcoma:Secondary to-I. Paget’s disease(paget’s sarcoma)II. Radiation or ingestion of radioactive material.

S.N PRIMARY OSTEOSARCOMA SECONDARY OSTEOSARCOMA

1. In young patients (10 - 25 years) Occurs in the elderly

2. 75% < age of 20  Secondary to malignant degeneration of pagets disease,extensive bone infarcts or post-radiotherapy

3. M>F M>F

4. Typically occur in the metaphyseal regions of long bones, and have a striking predilection for the knee (60%)

Wider distribution,higher incidence in flat bones, especially the pelvis.

Diagnosis1.Laboratory studies:CBC, ESR, CRP, LDH (elevated level indicates

poor prognosis)

ALP (Highly Osteogenic)

Platelet count, Electrolyte levels, Liver function

tests, Renal function tests, Urinalysis

2.Radiological features:Findings:Typical appearances include:Medullary and cortical bone destructionWide zone of transition Permeative or moth-eaten appearanceAggressive periosteal reaction Codman triangle Sunburst type lamellated (onion skin) reaction( less

frequently seen)soft-tissue mass tumour matrix ossification / calcificationvariable:  reflects a combination of the amount

of tumour bone production, calcified matrix, and osteoid

Cont..3. CT Scan: It is the most sensitive means in detecting

pulmonary metastasis. CT scanning may be helpful locally when the

radiographic appearances are confusing, particularly in areas of complex anatomy.

Cross-sectional images provide a clearer information of bone destruction, as well as the extent of any soft tissue mass, than do radiographs.

Cont..4. MRI It is the prime investigation of choice for

Osteosarcoma

An obvious heterogeneous tumor is

demonstrated with surrounded bones and

usually a soft tissue mass

Intramedullary skip lesion may also be identified

T1WIsoft tissue non-mineralized component :

intermediate signal intensitymineralised / ossified components : low signal

intensityperi-tumoural oedema : intermediate signal

intensityscattered regions of haemorrhage will have

variable signal

T2WIsoft tissue non-mineralized component : high

signal intensitymineralised / ossified components : low signal

intensityperi-tumoural oedema : high signal intensity

abnormal signal intensity in the metaphyseal marrow and the soft tissue mass (black arrow). Early tumor extension is shown beyond the growth plate into the epiphysis (white arrows).

Coronal T1-weighted MRI.

STIR suppresses signal from fat,Sensitive to edema and bone pathologyNormal marrow and fat: darkFluid & edema: bright

Bone findings:1. Increased signal in the medullary

canal.2. Irregular pattern in the metaphysis.3. Ill defined cortical outline.4. Extension to the epiphysis.5. High signal around distal femur,

suggesting edema and growth into the surrounding tissue.

Coronal STIR of the left knee

Cont..5.Biopsy to confirm the diagnosis.

Histology confirmed radiological suspicion of osteosarcoma in the distal femur of patient

1. Formation of new, abnormal bone with a coarse lacelike architecture2. Variable tumor cell size & shape, with hyperchromatic nuclei and mitoses.

Cont..6. Scintigraphy

Osteosarcomas typically show increased uptake of radioisotope on bone scans obtained by use of technetium-99m (99m Tc) methylene diphosphonate (MDP). A scan in the early blood-pool (left)

and delayed phases (right) demonstrates an extensive abnormality. the activity is more uniform and extensive than the apparent involvement shown on the plain film.

Cont..7. AngiogramAngiogram Determine vascularity of the tumour ,Detect vascular

displacement and relationship of vessels to the tumour

Telangiectatic osteosarcoma of the distal femur. predominantly radiolucent defect is shown on conventional radiograph.

Angiographically is shown to contain large, tortuous, pathological vessels.

Some confusion in nomenclature relates to osteosarcoma arising in or near the periosteum.

They are divided into two groups: a.Parosteal osteosarcoma and b.Periosteal osteosarcoma

Parosteal OsteosarcomaMost patient affected in 3rd & 4th decade.Typically dense tumour surrounds a long bone,particularly

femur or a tibia. Margin are sharply defined but tend to undulate.

The tumour is denser centrally and at the base than peripherally.

Characteristically there is a radiolucent zone between the ossified outer margins of the tumour and adjacent host bone.

Usually, the tumour appears to be attached to the cortex by a broad pedicle.

Parosteal osteosarcoma of the proximal humerus. A well-defined mass of dense tumour bone surrounds the humeral shaft.

Parosteal osteosarcoma arising from the anterior aspect of the femur shown angiographically to be unremarkable apart from a slight increase in the number of branches going into the tumour.

PAROSTEAL OSTEOSARCOMA

Telangiectatic Osteosarcoma (2.5-12.5%)Lytic tumors consisting of large cystic cavities

filled with blood usually diametaphyseal in location.

 Has been considered more aggressive than classic osteosarcoma, but studies of long-term survival after optimum treatment now indicate that the aggressiveness of telangiectatic osteosarcoma is similar to that of the classic type.

Frontal radiograph of the distal femur in a patient with telangiectatic osteosarcoma. the radiograph shows mixed medullary sclerosis and lucency, cortical destruction medially, aggressive periosteal changes, and a large soft-tissue mass with peripheral ossification

Sarcoma in Paget’s DiseaseMalignant tumours are said to arise in bone affected by

Paget's disease in about 1 % of cases.

Overall, the skull, pelvis and long bones are typical sites, predilection for the humerus in the later.

Men are more commonly affected, even allowing for the increased male incidence of Paget's disease.

However, the tumour is very aggressive and the outlook is very poor.

Radiologically, the lesion is lytic, mixed or sclerotic.

Xray of the proximal femur in a patient with Paget disease demonstrates the typical features of cortical thickening, osseous expansion, and trabecular coarsening. In addition, irregular bone lucency and cortical destruction are shown in the medial aspect of the shaft;

Coronal T1WIof the same patient showing -the tumor is shown in the proximal shaft of the right femur (white arrow), with cortical destruction and a large soft-tissue component (black arrow).

Treatment and PrognosisTreatment options for classic osteosarcomaSurgery alone: 20% cure rate.Surgery & chemotherapy: 60-80% cure rate.

Radical surgical treatment• Wide surgical resection

• Limb salvage (used in 80-90% of all cases) Bone replaced with a bone allograft or a

prosthesis.• Amputation Currently, the 5-year survival rate after adequate

therapy is approximately 60 - 80% .

Differential DiagnosisOsteomyelitisOther tumours :

metastatic lesion to boneMalignant round cell tumours (Ewing

sarcoma)

Age Age is the most important clue in differentiating

possible bone tumors. Osteosarcoma-Between 10 &25 yrs Ewing’s sarcoma-5 to 30 yrs.

Location within the skeleton

The location of a bone lesion within the skeleton can be a clue in differential diagnosis.

• Osteomyelitis-femur, tibia, humerus, fibula, radius• Osteosarcoma-femur• Ewing's sarcoma-iliac bone, fibula, rib, tibia,

humerus,pelvis.

Site and LocationOsteosarcoma Osteomyelitis Ewing’s

sarcoma

Site Metaphyseal Metaphysis Diaphysis

Location juxtacorticalcentricEccentric

juxtacortical centric

Periosteal reaction & Zone of transition

osteosarcoma Osteomyelitis Ewing’s sarcoma

Periosteal reaction

Sunburst spiculation

Formation of involucrum,sequestra

Onion peel lameller type

zone of transition

Wide zone of transition

Wide zone of transition

Wide zone of transition

Ewing's sarcoma. well-defined soft-tissue mass.

Advanced osteomvelitis involving the whole of the right tibia and lowervoend of fibula. Note sequestrum in tibia and further sequestrum being extruded from the fibula.

Osteosarcoma of the distal femur-. well-defined soft-tissue mass and radiating spiculation of calcification within it.

Thank You