OSTEOSARCOMA

 

 

 

Introduction: Osteosarcoma--is a highly malignant tumour arising with in

 the bone and rapidly spreading outwards to the 

periosteum and surrounding soft   tissue.

 Osteosarcoma is one type of malignant bone tumour that developed

in the osteoblast cells, which leads to formation of new bone and alternate with bone

 destruction.

 

Type of Osteosarcoma: 1.Intramedullary Osteosarcoma, 2.Periosteal 

Osteosarcoma, 3.Parosteal Osteosarcoma, 4.Talegiactetic Osteosarcoma, 5. Paget's

 Osteosarcoma.

 

Clinical Features: Common Age- Predominantly in children and  

 adolescent,  Common Site- Any bone may involved but common in long bone 

 metaphysis especially around the knee and upper humerus. Pain- More at Night and 

gradually increase in severity. Lump or swelling -rapidly increase in size,Extends

 into surrounding soft tissue. Pathological fracture,(Rare).

Look- Early stage-may normal,Late stage- Skin changes – overlying tissue swollen

         and inflamed

Feel-Early- Locally tender,  Temperature raised, Late- Palpable swelling, 

Lymph Node – Enlarged , Signs of neurovascular compression.

Investigation: Imaging-X-ray, CT scan, MRI, Bone Scan.Laboratory Findings, 

Hystopathology- Macroscopic and Microscopic Findings.

 

X-ray— Hazzy osteolytic area alternate with osteoblastic area  (Metaphysis).

 Ill defined Endosteal margin. Cortex is breached and tumour extends in  the soft tissue.

Sunburst effect- streaks of new bone appear radiating  outwards from the cortex.

Codmans triangle-  Tumour emerge from cortex and  reactive newborn formation at the

 angle of periosteal elevation.(Sunburst effect & Codmans triangle- Diagnostic)

 

CT-Scan- Extent of tumour, Pathological Fracture, Pulmonary CT – For Metastasis.

MRI—Extent of tumour, Soft tissue involvement, Content of tomour.

Radio isotope scan- Identify Skip lesion, Distant spreading.

 Pathology: Macroscopic- Bone destruction, Bone loss, Cavitation, Formation of 

dense new bone, Tumour extends into Medulla, physeal plate and surrounding soft 

tissue, Ossification at periosteal margin.   

Microscopic- Characteristic spindle cells with pink   staining osteoid tissue. Cartilage cell

 or fibrous tissue with little or no osteoid, Osteoid tissue is significant,(several sample

 should be examined),Area of Necrosis and hemorrhage , Marked Cellular Atypia . 

 

Differential Diagnosis-Post traumatic swelling, Infection, Stress fracture, 

 Aggressive cystic lesions.

 

Treatment—After Clinical assessment and advance imaging ,Patient is admitted in a

 special center, Biopsy done with grading and typing, The lesion usually IIA or IIB, 

Multi agent neo adjuvant chemotherapy for 8-12 weeks, When tumour resectable, no

skip lesion---wide resection carried out, Depending on site and size replace the bone 

segment with large bone graft or custom made implant. Amputation may appropriate

 in some case. Specimen is examined to asses the response the chemotherapy—If 

 tumour necrosis is marked-(more than   90%)Chemotherapy continued for   another

 6-12 months, If necrosis poor –different   chemotherapeutic agent   substituted.

 For pulmonary metastasis- If perepheraly placed-may be completely resected  with a 

wedge of lung tissue .

 

Outcome—Long term survival with wide resection rate-50-60%, 10 years survival with

 mechanical failure 75%, Limb salvage rate at 20y --84%.  

 

Parosteal Osteosarcoma-  Low grade osteosarcoma, Situated on the surface of

 long bone,common age- Young adult, Common Site-distal femur, proximal tibia. Present

 with slowly enlarging mass near bone end. X-ray: Shows-dense bony mass on the 

surface of boneor encircling, Cortex is not eroded, A thin gap may present between

cortex and tumour.

 Pathology- A hard bony mass, Microscopic-Well formed bone but without regular

 trabecular arrengement, trabecular space may contained cellular fibroblastic tissue, A

 few atypical cells and mitotic figures may seen.

Treatment-  Low grade-wide excision, Dedifferntiated- Treated As intramedullary

 Osteosarcoma.

 

 Periosteal Osteosarcoma-It is a rare bone tumour and more like a 

 intramedullary Osteosarcoma but situated on the surface of bone,C/F-Young adult,

 Local pain and swelling ,X-ray-Superfacial defect of cortex ,CT, MRI- Identify extend of

 tumour and reveal larger soft tissue mass,Hisology-True Osteosarcoma but prominent

 cartilageous elements. Treatment-As osteosarcoma.

 

Telangiectetic Osteosarcoma - is a malignant   bone tumor characterized by

 

 the presence of  dilated blood vessels within the tumor mass.

 

 

Paget’s Osteosarcoma-A high grade tumour with long standing Paget’s disease,

 

Treatment– Resection or amputation and chemotherapy- (5 years survival rate low)

 

 Extracompartmental- Paliative Radiotherapy.