Bone Tumors - Lecture 1

Bone Tumors - Lecture 1

• Tumours, tumour-like lesions, and cysts are grouped due to similar clinical presentation and management. Definitive classification is ongoing.

Clinical Presentation - History

• Tumours are often asymptomatic (discovered incidentally).
• Childhood and adolescent primary malignant tumors (Ewing's tumour, osteosarcoma) are common.
• Chondrosarcoma and fibrosarcoma are more common in older people.
• In patients over 70, metastatic bone lesions are more frequent than primary tumors.

Clinical Presentation - Symptoms

• Pain: Even tiny lesions can be very painful if encapsulated in dense bone (e.g., osteoid osteoma).
• Swelling: A visible lump can be alarming.
• Neurological symptoms: Paraesthesia or numbness can occur.

Clinical Presentation - Examination

• Examination focuses on the symptomatic area.
• Lymphatic drainage, pelvis, abdomen, chest, and spine should be assessed.

Imaging - X-Rays

• Questions to ask when studying an X-ray:
  • Is the lesion solitary or multiple?
  • What bone type is involved?
  • Location of the lesion in bone?
  • Are lesion margins well- or ill-defined?
  • Are there calcification flecks present?
  • Is the cortex eroded or destroyed?
  • Is there periosteal new bone formation?
  • Does the tumor extend into soft tissues?

Imaging - Other modalities

• Radioisotope scanning
• Computed tomography (CT)
• Magnetic resonance imaging (MRI)

Laboratory Investigations

• Blood tests rule out other conditions like infection, metabolic bone disorders, or hyperparathyroidism ('brown tumour').
• Increased erythrocyte sedimentation rate (ESR) and serum alkaline phosphatase are potential markers.
• Serum protein electrophoresis, urine for Bence Jones protein.

Biopsy

• Needle biopsy is common.
• Open biopsy is another option.
• Delay biopsy until all imaging is complete.

Differential Diagnosis

• Soft tissue haematoma
• Myositis ossificans
• Stress fracture
• Bone infection
• Gout

Staging of Bone Tumors

• Benign bone tumors are staged (latent, active, aggressive) as described by Enneking.
• Bone sarcomas are staged:
  • Stage I: All low-grade sarcomas.
  • Stage II: Histologically high-grade lesions.
  • Stage III: Metastasized sarcomas.

Treatment Methods

• Tumor excision
• Multi-agent chemotherapy
• Radiotherapy

Benign Bone Lesions

• Non-ossifying fibroma (fibrous cortical defect): A common benign developmental lesion in children, often found incidentally.
• Fibrous dysplasia: A developmental disorder where trabecular bone is replaced by fibrous tissue. Significant lesions may lead to fractures or deformities. Treatment depends on the lesion's size and symptoms.
• Osteoid osteoma: A tiny benign bone tumor (usually under 1 cm) commonly found in young adults. Pain is a key symptom, typically relieved by salicylates. Characterized by a small radiolucent nidus on X-ray. Treatment is complete removal of the nidus.
• Chondroma (enchondroma): Usually asymptomatic, discovered incidentally. They can occur at any age in almost any bone (especially hands and feet). Removal usually only necessary if the tumor grows or if it causes a pathological fracture.

Additional Types

• Osteochondroma (cartilage-capped exostosis): A common benign tumor that typically grows during the growth period of a bone
• Giant cell tumour of bone: Pain and swelling are common symptoms. The tumor can develop into a more aggressive type of cancer. It's frequently treated by curettage and bone grafting.
• Simple bone cyst: Benign lesion, often seen in children and teens. The cysts can heal on their own.
• Aneurysmal bone cyst: Usually in long bones. Radiolucent lesion found on X-rays (often trabeculated). MRI can confirm and it is curetted then filled with bone grafts.

This quiz covers the essential aspects of bone tumors, including their clinical presentation, common types, symptoms, and diagnostic imaging approaches. It focuses on the differences between primary malignant tumors and metastatic lesions, as well as the examination techniques used. Test your knowledge on the critical features associated with bone tumors.