A 20-year-old female was referred to our hospital due to deformity and bulging in anterior aspect of chest wall in sternal area.Chest X-ray and CT scan Canvas Jackets confirmed a large mass with destruction of sternum.Pathologic diagnosis after incisional biopsy Decorating Class was compatible with aneurysmal bone cyst.We resected sternum completely and reconstructed large anterior defect by a cryopreserved sternal allograft.In follow-up of patient there was no unstability of chest wall with good cosmetic result.