Benign bone cysts and fibrous dysplasia (tumour-like bone conditions)

• Benign lytic lesions of adolescents with clear zones of transition; aneurysmal bone cyst may show fluid levels on MRI; fibrous dysplasia has a ground-glass matrix.

• Presentation: painful swelling or pathological fracture. Differential: giant cell tumour, cartilage tumours.

• Investigations: X-ray, CT.

Management

• Surgery is the mainstay: curettage and bone grafting.

• Pathological fracture: internal fixation, or plaster immobilisation after curettage and grafting.

• Malignant bone tumours are managed as in the oncology chapter (refer to a musculoskeletal oncology centre).