The need for complete resection of chest wall tumors creates a huge challenge in terms of reconstructing the complex dynamics of the thorax. We are reporting a case of a low-grade fibromyxoid sarcoma (LGFMS) diagnosed in a young male, where the complete resection of the mass, sternum and parcially the pericardium was performed. Subsequently, a composite porous high-density polyethylene StarPore® prosthesis of the sternum and costal arches was used and the latissimus dorsi muscle free flap with skin graft was implanted over the sternum.