Imaging of ewing sarcoma: an updated analysis including presenting features, prognostic imaging biomarkers, and treatment response assessment.

Fig. 1. 17-year-old male with Ewing sarcoma of the left femur. Anteroposterior (AP) (A) and lateral (B) radiographs demonstrate a permeative lytic lesion (arrows) with a combination of "onion peel" periosteal reaction (arrowheads) and Codman's triangle (curved arrows). A large extraosseous component can be extrapolated from marked adjacent soft tissue thickening (*)

Fig. 2. 12-year-old female with Ewing sarcoma of the right scapula. AP (A) and lateral (B) radiographs demonstrate a permeative lytic lesion (arrows). Coronal (C) and axial (D) proton density (PD) fat saturation (FS) MRI images show significantly more extensive involvement than suggested on x-ray, as well as a considerable extra-osseous extension (arrows)

Fig. 3. 15-year-old female with Ewing sarcoma of the left femur. AP (A) and lateral (B) radiographs demonstrate a subtle mixed sclerotic and lucent lesion (arrows) with a medial Codman's triangle (curved arrow) and anterior "sunburst" periosteal reaction (arrowheads). Extra-osseous extension into the prefemoral space can be seen (*)

Fig. 4. 26-year-old male with Ewing sarcoma of the left mid femur. Coronal T1 (A) and STIR (B) MRI images demonstrate cortical thickening with saucerization defects (arrows) of both the medial and lateral aspects of the femoral shaft

Fig. 5. 33-year-old male with Ewing sarcoma of the proximal tibia. Axial CT (A) and axial T1 (B), STIR (C), and T1 FS post contrast (D) and sagittal T1 (E) MRI images demonstrating low to intermediate T1 signal, variable intermediate to high T2 signal, and heterogeneous enhancement with a linear lower-attenuation/intermediate signal intensity channel extending through the low signal intensity cortex (arrows) allowing communication between the intraosseous and soft tissue components with an adjacent associated soft tissue mass (arrowheads)

Fig. 6. 29-year-old male with Ewing sarcoma of the second metacarpal. Axial contrast-enhanced CT (A) and axial T2 (B) MRI images demonstrate a large extraskeletal mass (arrows) without any identifiable cortical disruption (arrowheads), also known as the wraparound sign

Fig. 7. 14-year-old female with Ewing sarcoma of the distal femoral epiphysis. Axial T1 (A) and STIR (B) and axial (C) and coronal (D) T1 FS post contrast MRI images demonstrate low to intermediate T1 signal, variable intermediate to high T2 signal, and heterogeneous enhancement with marked surrounding edema without an associated soft tissue mass. Axial STIR (E), DWI (F), and ADC map (G) images after radiation treatment demonstrate decreased T2 hyperintensity with few regions of T2 shine through but no restricted diffusion

Fig. 8. 38-year-old male with metastatic Ewing sarcoma. Sagittal T1 (A) and STIR (B) and T1 Dixon volumetric interpolated breath-hold examination (VIBE) post-contrast Water (C) and Fat (D) MRI images demonstrate metastases of the T10-12 vertebra (arrows) that enhance and replace the normal fatty bone marrow

Fig. 9. 38-year-old male with Ewing sarcoma of the left kidney. Tc99m-MDP bone scan demonstrates multifocal tracer uptake of ribs, vertebra, and the left ilium, corresponding to osseous metastases. Note the surgically absent left kidney

Fig. 10. 17-year-old male with Ewing sarcoma of the distal humerus. Lateral radiograph (A) demonstrates a permeative lytic lesion (arrows) with periosteal reaction (arrowheads). Sagittal T1 MRI (B) better shows the full extent of the lesion (arrows). Sagittal reformation of SPECT-CT Tc99m-MDP bone scan (C) displays intense tracer uptake within the lesion. Pre-treatment sagittal reformation of 18F-FDG PET-CT (D) reveals intense metabolic activity with an SUVmax of 4.8. After completing 9 weeks of chemotherapy with vincristine, doxorubicin and cyclophosphamide, sagittal reformation of 18F-FDG PET-CT (E) demonstrates resolution of the previously seen metabolic activity, indicating excellent treatment response. The patient subsequently underwent limb salvage surgery with wide resection, with a lateral radiograph (F) showing modular endoprosthesis placement

Fig. 11. 44-year-old female with pelvic Ewing sarcoma status post chemoradiation therapy. AP radiograph (A), coronal STIR MRI image (B) and coronal fused 18F-FDG PET-MRI image (C) demonstrate lytic/hyperintense left acetabular and superior pubic rami lesions (arrows) and small volume of fluid at the Girdlestone pseudoarthrosis (arrowheads) without significant metabolic activity, confirming treated disease

Fig. 12. 20-year-old male presented with a progressive, painful lump in the anterior aspect of the left leg. MRI. (A) T2 fat saturation axial image reveals an aggressive lesion of the tibial diaphysis (arrow) with a large extra-skeletal mass (asterisk). Orthopaedic oncologist submitted the patient to a CT-guided biopsy. (B) performed with an 8-gauge trap system needle (arrowhead). The final histopathological diagnosis was Ewing Sarcoma