X-Ray of a child’s femur. Clearly evident is an ill-defined osteolytic lesion (purple arrow). Osteolysis or an osteolyctic lesion refers to the pathological destruction or disappearance of bone tissue. This lesion has multiple small holes in the diaphysis (the shaft or central part) of the femoral bone creating a ‘moth-eaten’ appearance. There is also an aggresive periosteal reaction (blue arrows), this is the formation of new bone in response to stimulation or irritation of the periosteum, vascular connective tissue which surround the bone.(1) In the case of an aggresive periosteal reaction, the cortex (the hard outer layer of the bone tissue) displays a permeated pattern of destruction sometimes referred to as lamellated or ‘onion skin’ appearance because of successive layers of periosteal development. Sunburst appearance is seen here as a result of new bone being laid down. Findings Ewing’s Sarcoma.
Ewing’s sarcoma is a rare type of malignant bone cancer that most commonly occurs in the teenage and young adult years and is rarely seen in adults over the age of 30 years old. The disease is slightly more common in boys or young men and has a male/female ratio of 1.6:1.(2) Ewing’s sarcoma is characterized in histopathology as a small, round, blue-cell tumour. This type of tumour usually affects the long bones, most commonly occurring in the pelvis, femur, humerus, ribs, spine and clavicle. Ewing’s sarcoma is a type of bone carcinoma but it can also occur in the soft tissues, in this case it is known as ‘extraosseous Ewing’s sarcoma’. Another type of Ewing’s sarcoma is a primitive neuroectodermal tumour (PNET) which often arises in the brain, these can be found in either the bone or soft tissue. These group of tumours are sometimes collectively called ‘Ewing’s Sarcoma Family of Tumours’ (ESFT) or ‘Ewing’s Family of Tumours’ (EFT).
Lumbosacral MRI of the spine in a 15 year old male patient who presented with lower backache and weakness in the left lower leg. MRI showed sacral osteolytic lesion with soft tissue involvement causing neural compression. MRI is a very sensitive imaging method to detect lesions such as Ewing’s Sarcoma but differential diagnosis would include tuberculosis, osteosarcoma, lymphoma and chordoma as well. Although Ewing’s Sarcoma is rare it has to be considered in younger patients presenting with backache. Findings: (after histopathology) Ewing’s Sarcoma.
Ewing’s Sarcoma is a rare condition accounting for only 1% of all cancers in childhood and around 16% of all primary bone sarcomas and most commonly affects patients in the second decade of life (between 10 and 20 years old).(3) In the United States the incidence rate is around 4.6 cases per million in adolescents aged 15 – 19 years. On a global scale, the incidence rate is less than 2 cases per million children.(4) Ewing’s Sarcoma has a good prognosis if diagnosed early enough before metastatic spread, and is treated successfully in 50% to 75% of cases. The incidence of Ewing’s Sarcoma has not increased over the last 30 years and there has been a clear improvement in survival for both localized and metastatic disease.(5)
1. Ved N, Haller JO (November 2002). “Periosteal reaction with normal-appearing underlying bone: a child abuse mimicker”. Emerg Radiol 9 (5): 278–82. doi:10.1007/s10140-002-0252-5. PMID 15290554.
2. Burt M, Karpeh M, Ukoha O et al. (January 1993). “Medical tumours of the chest wall. Solitary plasmacytoma and Ewing’s sarcoma”. J. Thorac. Cardiovasc. Surg. 105 (1): 89–96. PMID 8419714.
3. Medicine, s cecil. Goldman (24th ed. ed.). Philadelphia: Elsevier Saunders. p. 1326. ISBN 978-1-4377-2788-3.
4. Ewing Sarcoma Imaging at eMedicine
5. Esiashvili N1, Goodman M, Marcus RB Jr. ‘Changes in incidence and survival of Ewing sarcoma patients over the past 3 decades: Surveillance Epidemiology and End Results data’. J Pediatr Hematol Oncol. 2008 Jun;30(6):425-30. doi: 10.1097/MPH.0b013e31816e22f3. [PubMed]