Craniofacial fibrous dysplasia is a non-malignant disease. It appears due to the mutations of the GNAS gene that results in inhibition of the differentiation and proliferation of bone-forming stromal cells and leads to the replacement of normal bone and marrow by fibrous tissue and woven bone. Sometimes it is isolated to a single or multiple skeletal sites and / or endocrine organ (1, 2, 3, 4).
The disease commonly progress as a slow developing mass. Distortion of optic nerve, eye ball, nasal airway, facial nerve, teeth and middle year ossicles can occur. In young patients, at prepubertal age, the growth is rapid and can cause aneurismal bone cysts or mucoceles (1, 3, 5). The malignant change to osteosarcoma or other form of sarcoma can appear in less than 1% of cases (1, 2).