Isolated fibrous dysplasia of the sphenoid sinus.

Fibrous dysplasia is an uncommon benign bone disorder of unknown etiology in which normal medullary bone is replaced by fibrotic and osseous tissue. Solitary involvement of the sphenoid sinus is unusual. Here, we present the case of a 28-year-old man complaining of occipital and vertical headache. Imaging modalities demonstrated an expansile lesion filling the entire sphenoid sinus. Biopsy specimen was obtained by endoscopic sphenoidotomy. Diagnosis of fibrous dysplasia was made by imaging results and pathologic examination.