Monostotic fibrous dysplasia originating from ethmoid bone: treatment with endoscopic approach.

We present a case of monostotic fibrous dysplasia of the ethmoidal sinus in an 11-year-old boy. This condition is of interest to the otorhinolaryngologist because of the difficulty of differential diagnosis and treatment. This tumorlike growth was not restricted to the right ethmoidal sinus, but also compressed the orbit and the globe. Endoscopic and transnasal removal of the mass with a drill was performed under general anesthesia. No residual tumor was observed 6 months later.