Synonyms

• Conventional osteosarcoma
• conventional High-grade osteosarcoma

Category

Bone

Behaviour

Malignant

Grade

High

Gender

Both equally

Tissue of Origin

Bone

Epidemiology

• Most common primary Malignant Bone tumour in children and young adults
• Peak incidence 2nd decade
• Predilection for distal femur, proximal tibia, proximal humerus
• 50% have metastases at diagnosis

Clinical Features

• Pain and swelling
• Pathological fracture
• Rapid tumour growth
• Systemic symptoms if metastatic

Location

• Distal femur (most common)
• Proximal tibia
• Proximal humerus
• Pelvis
• Spine
• Jaw

Imaging

• Plain radiograph: mixed lytic and sclerotic lesion with Sunburst periosteal reaction, Codman triangle
• MRI: defines soft tissue extension and marrow involvement
• CT chest: pulmonary metastases screening
• Bone scan or whole-body MRI: skeletal metastases

Pathology

• Malignant spindle cells producing osteoid and Bone
• Markedly atypical with High mitotic rate
• Necrosis Variable

Genetics

• TP53 mutations (Li-Fraumeni Syndrome)
• RB1 mutations
• Complex karyotype

Treatment

• Neoadjuvant chemotherapy (MAP: methotrexate, doxorubicin, cisplatin)
• Wide surgical resection
• Adjuvant chemotherapy

Prognosis

• 60-70% 5-year survival with modern chemotherapy and surgery
• Poor without treatment
• Metastatic disease significantly worsens prognosis

Key Points

• Neoadjuvant chemotherapy essential
• Biopsy must not compromise surgical margins
• Limb-salvage surgery preferred when feasible

Workup - Blood Tests

• FBC, U&E, LFTs
• Alkaline phosphatase and LDH
• Coagulation screen pre-treatment

Workup - Local Imaging

• Plain radiograph
• MRI with gadolinium of whole bone

Workup - Biopsy

• Core needle or open biopsy: confirm diagnosis
• Biopsy site and tract must be planned with surgeon
• Do not compromise surgical margins

Workup - Staging

• CT chest/abdomen/pelvis: standard staging
• Alkaline phosphatase/LDH: prognostic

Workup - Other

• MDT at specialist Bone sarcoma centre mandatory
• Cardio-oncology assessment for doxorubicin
• Audiology baseline for cisplatin