Anterior chest wall giant cell tumor.

Giant cell tumors (GCTs) of bone are rare primary neoplasms that usually originate from the epiphysis of long bones. Even when the tumor occurs in a rib, it is usually in the posterior aspect. We report a case of a GCT originating from the anterior arc of the rib in a 22-year-old woman presenting with a progressively growing thoracic mass in the right anterior chest wall. Through this case the authors emphasize not only the rarity of a bone GCT but also its unusual costal localization.