Ewing's tumour is responsible for about 10% of primary bone tumours in Causasians, and is rare in Africans. It consists of densely packed small round cells, and is sometimes considered to be a lymphoma or myeloma. It commonly arises in the diaphysis of a long bone; the femur (20%), the tibia (20%) the humerus (10%), and the pelvis (20%).
The patient presents with: (1) a moderately painful, tender, warm, bony swelling, mild fever, and a leucocytosis, or (2) with a pathological fracture. There is a 30% chance that he already has widespread metastases in his other bones.
EWING'S TUMOUR X-RAYS show a patchy osteoporosis, which is either ''moth eaten', or has defined lacunae. There is usually a periosteal reaction (typically ''onion skin') in the intermediate stage. This is not present at first, and disappears as the tumour expands.
DIFFERENTIAL DIAGNOSIS. Confirm the diagnosis by biopsy. Subacute and chronic osteomyelitis mimic Ewing's tumour closely. Other possibilities are metastatic neuroblastoma (rare), a non- Hodgkin's lymphoma in bone, and fibrous dysplasia.
PROGNOSIS. Untreated, almost no patients survive 5 years. 5 year survivals are: surgery alone 8%, radiotherapy followed by surgery 25%, surgery followed by radiotherapy 45%, radiotherapy and chemotherapy [pm]50%, surgery and chemotherapy [pm]50%.
MANAGEMENT. If possible refer the patient for radiotherapy and chemotherapy. If you cannot refer him, excise the tumour, if necessary by amputation, and give him chemotherapy.
An effective regime is: Actinomycin D, 2 mg/m['2], or 1 mg m['2] on days 1 and 3. Vincristine 1.4 mg/m['2]. And, cyclophosphamide, 1 g/m['2]. Adriamycin 60 mg m['2]. All intravenously every 21 days for 6 courses.