Because of difficulties in diagnosis of disorders of the sphenoid sinus posed by the isolated location of the sinus and non-specific initial symptoms, sphenoid sinus has been called the neglected sinus. Nevertheless, imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) or nasal endoscopy have led to considerable improvements in the diagnosis.

Herein, we report the case of an 85-year-old man who presented a history of headache and vomiting. CT revealed opacification of the sphenoid sinus with osteolysis of the clivus, but no abnormalities in any of the other paranasal sinuses. Immediately after endoscopic sphenoidotomy was performed, the patient’s headache resolved. At first, the mass was suspected as a metastasis from an abdominal malignant tumor, however, eventually, a diagnosis of chronic sphenoiditis was made.

Although isolated sphenoid sinus disease can be identified easily by CT or MRI, and transnasal endoscopic surgery can be performed safely, difficulties in diagnosis and cure without permanent sequelae remain, therefore, careful follow up is necessary.