What is the initial management approach for enchondroma (a type of benign bone tumor) of the bone?

Initial Management of Enchondroma of Bone

For asymptomatic enchondromas in the extremities, observation with radiographic monitoring is the recommended initial management approach, while symptomatic or expanding lesions should be treated with curettage with or without bone grafting.

Understanding Enchondromas

Enchondromas are benign cartilaginous tumors that arise from the medullary cavity of bone. They are one of the most common benign bone tumors and are characterized by:

• Typically found in the small bones of hands and feet, but can occur in long bones
• Usually asymptomatic and often discovered incidentally on radiographs
• May present with pain if pathological fracture occurs
• Rarely undergo malignant transformation to chondrosarcoma in solitary lesions

Diagnostic Approach

1. Initial Imaging:

   • Radiographs in two planes are the first-line investigation 1
   • Look for characteristic features: well-defined lucent lesion with internal calcifications

2. Advanced Imaging (if needed):

   • MRI is recommended if there is diagnostic uncertainty or to evaluate for aggressive features 1
   • Dynamic contrast-enhanced MRI can help differentiate between benign enchondroma and low-grade chondrosarcoma 1

3. Warning Signs requiring further investigation:

   • Pain without fracture
   • Cortical destruction
   • Soft tissue extension
   • Size > 5 cm
   • Axial skeleton location (higher risk of malignancy)

Management Algorithm

1. Asymptomatic Enchondromas in Extremities

• Recommended Approach: Active surveillance with regular radiographic monitoring 1
• Evidence: Multiple guidelines support observation for asymptomatic lesions, particularly in long bones 1
• Follow-up: Radiographs every 6-12 months for 2 years, then yearly as appropriate 1

2. Symptomatic Enchondromas in Extremities

• Recommended Approach: Curettage with or without local adjuvant therapy (e.g., bone grafting) 1
• Technique: Complete curettage with removal of all tumor tissue
• Bone Grafting: Often used to fill the defect after curettage
• Complications: Be aware that curettage has a reported complication rate of approximately 23% 2

3. Enchondromas in Axial Skeleton

• Recommended Approach: More aggressive surgical approach due to higher risk of malignancy
• Rationale: Axial skeleton enchondromas have higher risk of being or becoming chondrosarcoma 1

4. Special Considerations

• Multiple Enchondromas: Patients with multiple lesions (enchondromatosis/Ollier disease or Mafucci syndrome) have higher risk of malignant transformation and require closer monitoring 1
• Growth after skeletal maturity: Any growth of an enchondroma after skeletal maturity should raise suspicion for malignant transformation 1

Pitfalls to Avoid

1. Overtreatment: Unnecessary surgery for asymptomatic, stable lesions in extremities carries risk of complications 2

2. Undertreatment: Failing to recognize signs of potential malignancy (pain without fracture, growth, cortical destruction)

3. Misdiagnosis: The distinction between enchondroma and low-grade chondrosarcoma can be challenging, particularly in the axial skeleton 1

4. Inadequate Follow-up: Even benign-appearing lesions require appropriate surveillance to monitor for changes

By following this management approach, clinicians can appropriately balance the need to prevent complications from unnecessary procedures while ensuring adequate treatment for lesions with concerning features.