Extraosseous Ewing sarcoma | Figure 1

CincyKidsRad

Cincinnati Children's Radiology

Extraosseous Ewing sarcoma

Coronal (image 1) and axial (image 2 and 3) CT of the kidneys shows a poorly defined mass (arrow) in the upper pole of the right kidney. The mass was ultimately diagnosed as an extraosseous Ewing sarcoma. Extraosseous Ewing sarcoma is a rare variant of Ewing sarcoma typically occurring in the paravertebral spaces, lower extremities, head and neck, and pelvis. Renal involvement is uncommon. Patients with extraosseous Ewing sarcoma are typically older than those with skeletal tumors.