Definition
- Malignant marrow proliferation, mostly acute lymphoblastic leukaemia in children
Epidemiology
- Most common childhood cancer
- Peak age 2 to 5 years
Clinical Features
- Bone pain is the presenting feature in 15 to 30%
- Knee, ankle, wrist and hip most often painful
- Metaphyseal involvement
- Multiple sites may be affected
- Night pain, limp and refusal to weight bear
- Pain disproportionate to findings, or migratory joint pain
- Fever, pallor, bruising, lymphadenopathy and hepatosplenomegaly
Investigations
- FBC and blood film for cytopenias and blasts
- FBC can be normal early, so persistent suspicion warrants repeat testing
- Raised LDH, ESR and uric acid
- X-ray shows metaphyseal lucent bands, periosteal reaction, lytic lesions and osteopenia
- Vertebral compression fractures
- Bone marrow aspirate and biopsy confirms the diagnosis
Differential Diagnosis
- Juvenile idiopathic arthritis
- Osteomyelitis and septic arthritis
- Neuroblastoma metastases
- Ewing sarcoma
Management
- Avoid corticosteroids for presumed JIA until leukaemia is excluded
- Multiagent chemotherapy under paediatric oncology
- Event free survival for childhood ALL now exceeds 80%
Complications
- Steroid induced osteonecrosis, especially of the femoral head in adolescents
- Osteoporosis and fragility fractures during and after treatment
- Infection risk with neutropenia around surgery
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.