Figure 1 Magnetic resonance images of a 38-year-old man with extraskeletal Ewing sarcoma in the left paravertebral region. Sagittal (A) T1-weighted and (B) short tau inversion recovery images showed the lobulated soft tissue mass (arrow head) with a well-defined margin in the left paravertebral region. The lesion showed intermediate signal intensity on T1-weighting, with mild heterogeneity and hyperintensity on short tau inversion recovery imaging. (A) Patchy high-signal intensity was present within the mass, indicating hemorrhage (arrow). The psoas major muscle showed diffuse edema on (B) sagittal short tau inversion recovery imaging and (C) T2-weighted imaging; the normal muscle texture was maintained (arrow). (D) Axial T2-weighted image showed that the soft tissue mass extended into the left L1-L2 intervertebral foramen.