giant cell tumor of the sphenoid bone

background: giant cell tumor is a benign but locally aggressive bone neoplasm which uncommonly involves the skull. giant cell tumor (gct) of the sphenoid bone is relatively rare. in this report, we describe a tumor of the greater wing of left sphenoid bone. case presentation: a 31-year-old female was presented with headache, proptosis and diplopia of her left eye. cranial magnetic resonance imaging and ct scan showed an enhancing tumor at the junction of the orbital apex, ethmoidal and sphenoid sinuses. the tumor was removed and pathological examination confirmed a giant cell tumor.conclusion: this is the second report to describe the appearance of a gct of the part of sphenoid bone which caused proptosis of the unilateral orbit. radical excision of tumor was achieved which may be curative.