Isolated sphenoid sinusitis is rare and difficult to diagnose. The difficulty arises because it is located in the deepest part of the nasal sinuses and the associated inflammation does not lead to typical symptoms of sinusitis. There are many important structures in the vicinity of the sphenoid sinus: the internal carotid artery, cavernous sinus and cranial nerves. Therefore, sphenoid sinusitis causes severe complications.
From January 2003 to December 2007, we encountered 15 patients with isolated sphenoid sinusitis. Its incidence in all sinus diseases is 2.2%. Many patients complain of headaches, and they often visit neurologists or neurosurgeons. The pathological spectrum included 10 cases of bacterial sinusitis (5 acute sinusitis, 3 chronic sinusitis and 2 asymptomatic sinusitis), 3 fungal sinusitis, 1 mucocele and 1 retention cyst. When we diagnose isolated sphenoid sinusitis, CT and endoscopy are essential. CT becomes a more useful tool for performing a differential diagnosis when we independently change the window height and width. The endoscopic findings regarding draining from the sphenoethmoidal recess may indicate the severity of inflammation. A detailed observation with CT and endoscopy is the most important to accurately diagnose the pathology of isolated sphenoid sinusitis.