"Onodi air cells are usually asymptomatic, unless complicated by sinus disease (e.g. mucocoeles, squamous cell carcinoma, and acute rhinosinusitis, which have all been reported in sphenoethmoidal air cells), leading to early optic nerve involvement."
"The importance and variability of the posteriormost ethmoidal air cells was described by the Hungarian laryngologist Adolf Ónodi (1857-1920) in 1904 6,7."
"Rarely, it may lie superiorly to the sphenoid sinus and is then called a central Onodi air cell 4."
"Onodi air cells are usually asymptomatic, unless complicated by sinus disease (e.g. mucocoeles, squamous cell carcinoma, and acute rhinosinusitis, which have all been reported in sphenoethmoidal air cells), leading to early optic nerve involvement."
"Haller cells: infraorbital ethmoidal air cells"
"The sphenoethmoidal air cell is generally defined as the most posterior ethmoidal air cell, that extends posteriorly to lie superolateral to the sphenoid sinus and thus in close proximity to the optic nerve and internal carotid artery 5,8. It often extends into the anterior clinoid process; importantly, aeration of the anterior clinoid process does not imply presence of an Onodi cell, as frequently such aeration is due to recesses of the sphenoid sinus 9."
"The incidence of sphenoethmoidal air cells is variable, reported in 3.4 to 60% of individuals 1,8; the discrepancy of these rates of incidence likely results from variability in definition rather than true incidence 8."