Chondrosarcoma

Subtypes

• Classic Intramedullary
• De-differentiated Chondrosarcoma
• Clear Cell Chondrosarcoma
• Mesenchymal Chondrosarcoma

Intramedullary Chondrosarcoma

Epidemiology

• Affects older patients (>45 years)
• Slightly more common in males

Aetiology

• Unknown
• Associated with:
  • Expression of telomerase and RT gene
  • Presence of metastases
• Rarely arises from solitary enchondroma (1%)
• Increased risk in:
  • Ollier’s disease (20%)
  • Maffucci’s disease (100%)

Presentation

• Slow-growing painful mass
• Bowel and bladder symptoms if pelvic involvement

Clinical Features

• Prognosis depends on grade:
  • Most are low-grade
  • High-grade tumors, especially de-differentiated, are aggressive

Location

• Common sites:
  • Shoulder
  • Pelvis
  • Proximal femur
  • Hand

Imaging Features

• Features vary by grade but typically include:
  • Cortical erosion and breach
  • Cortical thickening
  • Chondroid spiculing and matrix
  • Soft tissue mass
  • Periosteal reaction
• Bone Scan: High uptake in all grades and subtypes
• MRI and CT: Critical for assessing soft tissue extent and surgical planning

Pathology

• Diagnosis may be challenging; histology is often featureless.
• Hallmark: Invasion of trabecular bone
• Other features:
  • Large pleomorphic cells
  • Binuclear nuclei
  • Plump and large nuclei

Management

• Not radiosensitive or chemosensitive
• Low-grade tumors: Treated with intralesional curettage and grafting
• High-grade tumors:
  • Wide or radical surgical resection
  • Amputation for pelvic lesions if necessary
  • Lung metastases resectable if feasible

Outcomes

• Prognosis depends on grade:
  • Grade 1: 90%
  • Grade 2: 60%
  • Grade 3: 30%
  • De-differentiated: 10%
• Low-grade tumors may progress slowly over 20+ years.

De-differentiated Chondrosarcoma

• Same locations as intramedullary chondrosarcoma
• Highly malignant
• Comprises low-grade chondrosarcoma overlaid on a spindle cell tumor (e.g., osteosarcoma)
• Features:
  • Bimorphic radiologic and histologic appearance
• Treatment:
  • Wide or radical resection for chondroid component
  • Chemotherapy for sarcoma component

Clear Cell Chondrosarcoma

• Rare
• Radiologic Features:
  • Lytic, well-demarcated lesion in the epiphysis of long bones
  • Differential diagnosis: Chondroblastoma
• Characteristics:
  • Low or intermediate grade
• Treatment:
  • Same as other chondrosarcomas
• Prognosis:
  • 80% long-term survival

Mesenchymal Chondrosarcoma

• Very rare
• Occurs in flat bones; lesions are lytic
• Affects younger patients rather than older adults
• Prognosis:
  • 50% survival at 5 years