Synonyms

• Conventional chondrosarcoma
• primary chondrosarcoma

Category

Bone

Behaviour

Malignant

Grade

Variable

Gender

Both equally

Tissue of Origin

Cartilage

Epidemiology

• Second most common primary Malignant Bone tumour in adults
• Peak incidence 4th-6th decades
• Predilection for pelvis, femur, humerus
• IDH wild-type generally grade 2-3; IDH-mutant grade 1

Clinical Features

• Pain
• Swelling
• Slow-growing
• Constitutional symptoms if advanced

Location

• Pelvis (most common)
• Distal femur
• Proximal humerus
• Ribs
• Proximal femur
• Tibia

Imaging

• Plain radiograph: mixed lytic and sclerotic lesion with Rings and arcs calcification
• CT chest: pulmonary staging
• MRI: assess soft tissue and marrow involvement

Pathology

• Malignant cartilaginous differentiation
• Atypical chondrocytes
• Grading 1-3
• IDH1/2 mutations present in many

Genetics

• IDH1/2 mutations in 60%
• CDKN2A deletion in High-grade
• TP53 mutations in some

Treatment

• Wide surgical excision: primary treatment
• Chemotherapy and radiotherapy limited role
• Targeted therapy with IDH inhibitors under investigation

Prognosis

• Grade-dependent: 90% 5-year for grade 1, 50% for grade 3
• IDH-mutant tumours may have better prognosis

Key Points

• IDH mutation status important for prognosis and emerging therapy
• Wide excision critical
• Chemotherapy generally not effective

Workup - Blood Tests

• FBC, U&E, LFTs
• LDH

Workup - Local Imaging

• Plain radiograph
• MRI with contras of whole bone to assess local extent
• CT may aid in characterisation of bony detail

Workup - Biopsy

• Core needle biopsy: adequate tissue for grading
• IDH mutation testing recommended

Workup - Staging

CT chest: pulmonary metastases

Workup - Other

MDT at Bone sarcoma centre

Follow-up Summary

• Post-operative visit at 6 weeks
• Year 1–2: 3-monthly clinical examination, plain films of primary site, and CXR
• Year 3–5: 6-monthly clinical examination, plain films of primary site, and CXR
• Year 6–10: Annual clinical examination, plain films of primary site, and CXR
• Discharge at 10 years from surgery