Eosinophilic granuloma simulating an aggressive rib neoplasm: CT evaluation.

Eosinophilic granuloma of bone can pose difficulties in diagnosis. We report a case of eosinophilic granuloma of rib origin in a child presenting with an enlarging chest mass whose appearance on computed tomography suggested Ewing sarcoma. Eosinophilic granuloma should be included in the differential diagnosis of an aggressive rib mass on CT in the pediatric patient.