Imaging characteristics of primary cranial Ewing sarcoma.

Background: Ewing sarcoma accounts for 10-15% of all childhood malignant bone tumours and is second in prevalence to osteosarcoma. The skull bones are an unusual site of origin of primary Ewing sarcoma in children. Previous reports concentrate on the neurosurgical aspects and relatively good outcome compared to other bone tumours of the calvarium. Reported cases mainly describe the imaging characteristics on CT.

Objective: To describe the MRI and CT features of primary cranial Ewing sarcoma.

Materials And Methods: The neuroimaging of three cases of primary cranial Ewing sarcoma are reviewed.

Results: Our three cases show an extra-axial mass that is high attenuation on CT and low signal on T2-weighted MRI. Haemorrhagic components, dural extension and contrast enhancement are also characteristic features.

Conclusion: CT attenuation and magnetic resonance signal characteristics reflect sheets of densely packed cells seen in Ewing sarcoma.