Hi, Thanks for writing in. The pain in costochondritis is typically in the front of chest next to the sternum and might cause lot of distress. It is a sharp pain. Breast implants can cause irritation of the nerves in the anterior chest wall causing pain perception. This pain is more localized to the area where implants are present and usually does not radiate to other places. Metastasis is pain due to bone destruction. This is diffuse pain which increases on palpation and focused on the area overlying the bone. It is suggested that you get a chest X ray or CT scan done to evaluate in detail the cause and nature of problem leading to the pain.