Question
A 12 year old girl has thigh pain, fever and weight loss. Radiographs show a permeative lytic lesion of the femoral diaphysis with an onion skin periosteal reaction.
- What is the differential diagnosis?
- What investigations confirm the diagnosis?
- How is it treated and what is the prognosis?
Answer
Differential diagnosis
- Ewing sarcoma, a small round blue cell tumour
- Osteomyelitis
- Langerhans cell histiocytosis
- Lymphoma and leukaemia
- Osteosarcoma
Investigations
- FBC, ESR, CRP and LDH, with LDH a marker of tumour burden
- MRI of the whole bone and CT of the chest
- PET CT or bone scan and bone marrow biopsy for staging
- Core biopsy at the sarcoma centre showing small round blue cells, CD99 positive
- Translocation between chromosomes 11 and 22 producing the EWS-FLI1 fusion gene
Treatment and prognosis
- Multiagent neoadjuvant chemotherapy (vincristine, doxorubicin, cyclophosphamide alternating with ifosfamide and etoposide)
- Local control with wide surgical resection where possible, or radiotherapy, as Ewing sarcoma is radiosensitive
- Adjuvant chemotherapy after local control
- Five year survival about 70% for localised disease and under 30% with metastases
- Poor prognostic factors are metastases, pelvic site, large tumour, high LDH and poor chemotherapy response
Related pages
Author Contributions
Orthofracs team
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.