[Monostotic fibrous dysplasia of the frontal sinus with orbital extension].

We present the case of a localized monostotic fibrous dysplasia in the frontal sinus with orbital extension and persistency after the first surgery; it had to be operated again with a fronto-orbitary reconstruction. The fibrous dysplasia is a rare bony alteration with transformation of the healthy bony tissue for a disestructuredone. Its etiology is unknown and can be associated to different syndromes, such as Albright's Disease. Its treatment is surgical, but presents a high percentage of recurrence, this is the xenson why it needs a close follow up.