Abstract
A 13-year-old boy presented with a growing lump on his left clavicle for 5 months. The plain radiograph revealed an osteolytic mass with aggressive periosteal reaction, suggesting a malignant lesion. The results of advanced imaging and histopathological examinations revealed that the patient had Ewing sarcoma without metastasis. The two-stage surgery was as follows: resection-observation-reconstruction. The underlying rationale was that Ewing sarcoma has a high recurrence. After 2 years of resection, the patient had remission, and he currently has a personal 3D-printed titanium implant with intact shoulder function.