Chondrosarcoma
Summary
Chondrosarcoma is a malignant bone tumour producing cartilaginous matrix. It is the second most common primary bone malignancy (after Osteosarcoma) and is the most common primary bone sarcoma in adults over 40 years. Unlike Osteosarcoma and Ewing Sarcoma, Chondrosarcoma typically affects older patients (40-70 years) and has a predilection for the axial skeleton (Pelvis, Proximal Femur, Shoulder). The hallmark radiological feature is "Popcorn" or "Ring and Arc" Calcification representing chondroid matrix. Crucially, Chondrosarcoma is notoriously resistant to chemotherapy and radiotherapy; surgical excision is the ONLY curative treatment. Grading (I-III) determines prognosis - Low-grade (Grade I) tumours have excellent outcomes, while High-grade (Grade III) and Dedifferentiated variants carry poor prognosis. [1,2]
Clinical Pearls
Surgery is the ONLY Cure: Chondrosarcoma is resistant to Chemotherapy and Radiotherapy. You MUST cut it out completely.
"Popcorn Calcification": The radiological buzzword. Also described as "Ring and Arc" calcification. Represents cartilaginous matrix.
Adult Bone Tumour: Unlike Osteosarcoma (teenagers) and Ewing's (children/teens), Chondrosarcoma affects older adults (40-70 years).
Pelvis is Common (and Hard): The pelvis is the most common site, and pelvic chondrosarcomas are difficult to resect with adequate margins.
Demographics
| Factor | Notes |
|---|---|
| Age | Peak: 40-70 years (Unlike Osteosarcoma which peaks in teens). |
| Sex | Male > Female (Slight predominance). |
| Incidence | ~200 cases/year in UK. |
Sites of Involvement
| Location | Frequency |
|---|---|
| Pelvis | Most common (~25%). |
| Proximal Femur | Common. |
| Proximal Humerus (Shoulder) | Common. |
| Ribs | Less common. |
| Hands/Feet | Rare (Usually benign enchondromas here). |
Risk Factors / Precursor Lesions
- Enchondroma: Benign cartilage tumour can undergo malignant transformation (~1% risk in solitary enchondroma).
- Ollier Disease: Multiple enchondromatosis. ~25% risk of malignant transformation.
- Maffucci Syndrome: Multiple enchondromas + Soft tissue haemangiomas. High malignancy risk (~50%).
- Osteochondroma: Rarely can transform into Secondary Chondrosarcoma.
Classification by Origin
- Primary Chondrosarcoma: Arises de novo in previously normal bone.
- Secondary Chondrosarcoma: Arises from pre-existing benign cartilaginous lesion (Enchondroma, Osteochondroma).
Histological Grading (Critical for Prognosis)
| Grade | Cellularity | Mitoses | Clinical Behaviour |
|---|---|---|---|
| Grade I (Low) | Low cellularity | Rare | Slow-growing. Rarely metastasizes. Excellent prognosis. |
| Grade II (Intermediate) | Moderate | Occasional | Intermediate behaviour. |
| Grade III (High) | High cellularity | Frequent | Aggressive. Metastasizes (Lung). Poor prognosis. |
Special Variants
| Variant | Notes |
|---|---|
| Dedifferentiated Chondrosarcoma | Low-grade cartilage + High-grade non-cartilaginous component (e.g., Fibrosarcoma). Very aggressive. Poor prognosis. |
| Mesenchymal Chondrosarcoma | Rare. Affects younger patients (20-30s). More chemo-sensitive than conventional. |
| Clear Cell Chondrosarcoma | Low-grade. Affects epiphyses of long bones. Good prognosis. |
| Condition | Key Features |
|---|---|
| Chondrosarcoma | Adult >40, Pelvis/Prox Femur, Popcorn calcification, PAINFUL. |
| Enchondroma | Any age, Hands/Feet common, Popcorn calcification, PAINLESS. |
| Osteosarcoma | Teenagers, Distal Femur/Proximal Tibia, Sunburst pattern, Aggressive. |
| Ewing Sarcoma | Children/Teens, Diaphysis of long bones, "Onion Skin" periosteal reaction, Systemic symptoms. |
| Metastatic Bone Disease | Older adults, Multiple lesions, Known primary (Breast, Prostate, Lung, Kidney, Thyroid). |
| Chondromyxoid Fibroma | Benign, Eccentric metaphyseal lesion, Young adults. |
Key Distinction: Enchondroma vs Chondrosarcoma
| Feature | Enchondroma | Chondrosarcoma |
|---|---|---|
| Pain | PAINLESS | PAINFUL (Night pain) |
| Location | Hands/Feet | Pelvis/Axial |
| Cortex | Intact | Endosteal scalloping, Cortical destruction |
| Size | Usually less than 5cm | Often >5cm |
Symptoms
| Symptom | Notes |
|---|---|
| Pain | Deep, dull ache. Worse at NIGHT (Classic bone tumour red flag). |
| Mass/Swelling | Slowly enlarging hard mass. |
| Pathological Fracture | Through weakened bone. |
| Duration | Often months to years of symptoms (Slow-growing). |
Signs
Imaging
| Modality | Findings |
|---|---|
| Plain X-Ray | "Popcorn" Calcification (Ring and Arc pattern). Endosteal scalloping (>2/3 cortical thickness = Concerning). Bone destruction. Soft tissue extension. |
| MRI | High T2 signal (Cartilage is water-rich). Defines soft tissue extent. Essential for surgical planning. |
| CT Thorax | Staging for lung metastases. |
| Bone Scan | Increased uptake. Helps identify skip lesions or other metastases. |
Biopsy
- Essential for Diagnosis: But challenging - Low-grade chondrosarcoma can look identical to benign enchondroma on histology.
- Pain is the Key Clinical Discriminator: Painful lesion = Presume malignant.
- Open Biopsy / Core Biopsy: Under image guidance by the operating surgeon or specialist radiologist.
Management Algorithm
SUSPECTED CHONDROSARCOMA
(Adult >40, Painful lesion, Popcorn calcification)
↓
STAGING INVESTIGATIONS
- MRI of Lesion (Local extent)
- CT Thorax (Lung mets)
- Biopsy (Confirm diagnosis and Grade)
↓
MDT DISCUSSION (Sarcoma MDT)
- All cases must go through specialist bone tumour centre
↓
TREATMENT BY GRADE
┌────────────────┴────────────────┐
GRADE I (Low) GRADE II/III (Intermediate-High)
↓ ↓
INTRALESIONAL CURETTAGE WIDE LOCAL EXCISION
+ Local Adjuvants (Tumour + Cuff of Normal Tissue)
(Phenol, Cryotherapy) - Aim for R0 resection (Clear margins)
- For small, contained lesions - Reconstruction:
• Endoprosthesis (Mega-prosthesis)
• Allograft
• Amputation (If limb salvage not possible)
↓
CHEMO/RADIOTHERAPY?
┌──────────────────────────────────────────────────────────┐
│ CONVENTIONAL CHONDROSARCOMA: │
│ ❌ Chemotherapy = INEFFECTIVE │
│ ❌ Radiotherapy = INEFFECTIVE │
│ (Chondrosarcoma is notoriously resistant) │
│ │
│ EXCEPTIONS: │
│ - Mesenchymal Chondrosarcoma: May respond to chemo │
│ - Dedifferentiated: May trial chemo for high-grade │
│ non-cartilaginous component │
└──────────────────────────────────────────────────────────┘
↓
FOLLOW-UP
- Regular clinical and radiological surveillance
- Lung CT for metastases
- Local MRI for recurrence
Surgical Principles
- Limb Salvage: Preferred when possible with adequate margins.
- Amputation: May be necessary for large pelvic tumours or neurovascular involvement.
- Margins: The most important prognostic factor for local recurrence.
| Complication | Notes |
|---|---|
| Local Recurrence | Main risk if margins inadequate. |
| Pulmonary Metastases | Most common site of distant spread (Especially Grade III). |
| Limb Loss | Amputation may be required. |
| Functional Impairment | Post-surgical. Requires rehabilitation. |
| Dedifferentiation | Low-grade tumour can transform into high-grade. |
| Grade | 10-Year Survival | Notes |
|---|---|---|
| Grade I | ~90% | Excellent prognosis. Rarely metastasizes. |
| Grade II | ~60-80% | Intermediate. |
| Grade III | ~30-50% | Poor. High metastatic potential. |
| Dedifferentiated | ~20-30% | Very poor prognosis. |
Prognostic Factors
- Histological Grade: Most important factor.
- Surgical Margins: Positive margins = High recurrence.
- Location: Pelvic tumours harder to resect → Worse outcomes.
- Size: Larger tumours = Worse prognosis.
Key Guidelines
| Guideline | Organisation | Key Recommendations |
|---|---|---|
| Bone Sarcoma Management | BOAST / BOA | Refer all suspected bone tumours to specialist sarcoma centre. |
| ESMO Bone Sarcoma Guidelines | ESMO (2018) | Surgical excision. No role for routine chemo/RT. |
| NICE Suspected Cancer Referral | NICE NG12 | 2WW referral for suspected bone cancer (Night pain, Unexplained bone pain >3 weeks). |
What is Chondrosarcoma?
It is a cancer of the cartilage cells inside the bone. Unlike most cancers, it grows slowly and mainly affects people in their 40s-70s. The most common places are the pelvis and hip area.
Is it treatable?
Yes, but the only way to cure it is surgery to cut it out completely. Unfortunately, chemotherapy and radiotherapy (which work for other cancers) do not work well for this type of tumour.
What happens after surgery?
Depending on where the tumour was, you may need reconstruction with a metal replacement or bone graft. You will need physiotherapy and regular scans to check it hasn't come back.
Primary Sources
- Gerrand C, et al. UK guidelines for the management of bone sarcomas. Clin Sarcoma Res. 2016;6:7. PMID: 27094006.
- Casali PG, et al. Bone sarcomas: ESMO-EURACAN Clinical Practice Guidelines. Ann Oncol. 2018;29(Suppl 4):iv79-iv95. PMID: 30285218.
Common Exam Questions
- Radiological Sign: "What is the classic X-ray appearance of Chondrosarcoma?"
- Answer: "Popcorn" Calcification (Ring and Arc pattern).
- Treatment: "Why is chemotherapy ineffective in Chondrosarcoma?"
- Answer: Chondrosarcoma is resistant to chemotherapy – low mitotic rate and poor drug penetration.
- Distinction: "How do you differentiate Enchondroma from Chondrosarcoma?"
- Answer: Pain – Enchondroma is painless; Chondrosarcoma is painful (especially night pain).
- Age Group: "Which bone sarcoma affects older adults (>40)?"
- Answer: Chondrosarcoma (Osteosarcoma = Teens, Ewing's = Children).
Viva Points
- Pelvic Chondrosarcoma: Most common site, but hardest to operate on with adequate margins.
- Dedifferentiated Subtype: Contains both low-grade cartilaginous component AND high-grade spindle cell component. Very aggressive.
- Secondary Chondrosarcoma: From pre-existing Enchondroma (Ollier) or Osteochondroma. Watch for new pain in known lesion.
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists.