osteosarcoma
TRANSCRIPT
OVERVIEWOVERVIEW• Introduction • Epidemiology• Classification• Skeletal Distribution• Etiology• Clinical and Radiographic features• Histopathology• Staging• Treatment and Prognosis
INTRODUCTIONINTRODUCTION
• 2nd most common primary malignant bone tumor after multiple myeloma.
• Arise from primitive mesenchymal bone forming cells
• Formation of osteoid directly by sarcoma cells.
EPIDEMIOLOGYEPIDEMIOLOGY
Involves any age but highest occurrence in adolescence i.e,10 to 25 yrs
Males > Females Blacks > Whites
OSTEOSARCOMA
Primary Secondary
Central(intra-
medullary)
Intra Cortical
Peripheral(juxta-cortical)
High Grade
Low Grade
• Paraosteal• Periosteal• High grade
surface OS
• Conventional OS• Telangiectactic OS• Small cell OS
Sequelae of .•Pagets Disease•Chemotheraphy•Chondrosarcoma- dedifferentiation
CLASSIFICATICLASSIFICATIONON
INTRA CORTICALINTRA MEDULLARY(central)
JUXTA CORTICAL(surface)
• 95%• Metaphysis• Fast growing
• Very rare• Diaphysis
• 5%• Metaphysis or Diaphysis• Slow growing
ETIOLOGYETIOLOGY• Exact cause is unknown.• Risk Factors
– Rapid bone growth– Environmental
Radiation Oncogenic virus
– Genetic Mutation of RB gene Li Fraumeni syndrome – Mutation in p53 tumour suppressor gene Rothmund Thomson syndrome (Autosomal Recessive)
– Pre existing lesions – Ex: Fracture of bone, Infarcts, Pagets disease etc
SKELETAL DISTRIBUTIONSKELETAL DISTRIBUTION• Sites
– Metaphysis > Diaphysis > Epiphysis
[89%] [10%] [1%]
• Distal Femur [40%]• Proximal Tibia [20%]• Proximal Humerus [10%]• Others – Jaw [8%] or
Pelvis [8%]
CLINICAL AND CLINICAL AND RADIOGRAPHIC FEATURESRADIOGRAPHIC FEATURES Clinically• Pain• Swelling• Loosening of teeth• Paresthesia• Nasal obstruction
Radiographically
• Codmans triangle• Sunburst appearance• Symmetric widening of periodontal
ligament.
Radiographically
• Codman’s triangle : Formed at the angle between the elevated periosteum and underlying surface of cortex.
PATHOLOGYPATHOLOGY GROSSLY :• Grey white• Bulky mass• Codmans triangle• Cut surface shows areas of
hemorrhages and necrotic bone.
g
HISTOLOGICALLYHISTOLOGICALLY : • Sarcoma cells - Undifferentiated mesenchymal
stromal spindle shaped cells with hyperchromatic nuclei.
• Osteogenesis – Osteoid matrix and bone is found interspersed in the areas of tumour cells.
Osteiod production
Spindle cells with hyperchromatic nuclie
Histologic variants• Telangiectactic: Large,cavernous,dilated
vascular channels.
• Small cell: Small,uniform tumour cells.
• Fibrohistiocytic: Resembles malignant fibrous histiocytoma
• Anaplastic: Marked anaplasia
• Well differentiated: Minimal cytologic atypia
EVALUATIONEVALUATIONMedical history and physical examinationConfirmed by investigations• Plain x ray• MRI scan• CT scan• Angiogram• Bone scan• Laboratory studies• Biopsy
STAGINGSTAGING• To stratify risk groups Stages :• Stage I - Low grade lesions• Stage II - High grade lesions• Stage III - Metastatic disease Substages :• A - Intramedullary lesions• B - Local extramedullary spread
TREATMENT (plan) TREATMENT (plan) • Radiological staging• Biopsy to confirm diagnosis• Preoperative chemotherapy• Repeat radiological staging (access chemo response, finalize
surgical treatment plan)• Surgical resection with wide margin• Reconstruction using one of many techniques
• Post op chemotherapy based on pre op response
ChemotherapyChemotherapy
• Preoperatively - Neoadjuvant chemotherapy (to decrease spread of tumour cells during surgery; treat micrometastasis)
• Postoperatively - Adjuvant chemotherapy
SurgerySurgery
For safe and complete removal of tumor Methods :a.Amputation
b.Limb savage procedure
c. Rotationplasty
• In mandible - Hemimandibulectomy
• Maxillectomy is difficult to perform due to the involvement of adjacent structures like maxillary sinus, pterygopalatine fossa and orbital fossa.