Well simple bone cyst should be explored by a surgeon to rule out other pathological entities that it could be. Also one of the main ways to get bone to form in the area is for the surgeon to curretage the inside walls of the cyst to allow blood to fill the cavity, become a clot, then get replaced by bone. only can you have a definitive diagnosis of simplebone cyst, traumatic bone cyst, is when you open up into a cavity that is not lined by epithelium.