Ewing tumor of rib: radiologic findings and computed tomography contribution.

The ribs are frequent sites of primary Ewing tumor accounting for about 10-12% of all cases. The lesions may be predominantly lytic or sclerotic or show a combination of bone destruction and secondary reactive changes. In some patients bony changes are subtle and are obscured initially by frequently associated large extrapleural masses or pleural fluid. These patients may present clinically with findings secondary to compression of mediastinal structures by the soft tissue masses. Computed tomography (CT) is of great value in the diagnosis of such difficult cases and better demonstrates the tumor extent and relationships than other available imaging modalities. CT is also of considerable help in determining the optimal time for en bloc tumor resection. Many tumors are initially considered non-resectable due to extensive involvement of the lung, the mediastinum, or the diaphragm. CT accurately documents tumor regression during preoperative courses of chemotherapy.