Translational Research in Anatomy (Sep 2022)
Unusual large central sphenoethmoidal cell separating the two sphenoid sinuses - A case report
Abstract
Background: The preoperative study of the sphenoid sinus and sphenoethmoidal cells is fundamental for successful surgery and complication avoidance. Sphenoethmoidal cells are those cells that extend superolaterally into the ipsilateral sphenoid sinus, from the most posterior part of the ethmoid. These sinuses are very variable due to their different pneumatization patterns. One study reported a central Onodi cell but it was small, lying above the sphenoid sinuses and not separating them. Case report: This article is to report a CT scan of a central sphenoethmoidal cell that is unusually big and is completely separating the sphenoid sinuses. A large sphenoethmoidal cell was fond, that extends into the sphenoid bone, completely separating the smaller right and larger left sphenoid sinuses. This sphenoethmoidal cell was referred to as an “H cell,” to differentiate it from Onodi cell which is also a sphenoethmoidal cell. The H cell, in this case is a left posterior ethmoidal cell that extends posteriorly into the body of the sphenoid bone, making a great proportion of the sphenoid bone pneumatization that is usually made by both sphenoid sinuses. In this case, the right sphenoid sinus is small and located anteriorly and laterally. The left sphenoid is funnel shaped, with its anteriorly pointing tube-like part ending in its ostium and its posterior, larger part occupying the full width of the inferior part of sphenoid bone pneumatization. H cell is pneumatising the sphenoid bone to the anterior wall of the sella turcica, passing below it, pneumatising the bone posterior to the posterior sellar wall, where it meets the transverse wall of the left sphenoid sinus below it. Conclusion: H cell can be readily misinterpreted as a sphenoid sinus, so a future study should look at its actual incidence and variety. It carries a considerable risk of surgical complications. Careful reading of the CT scan is important to check the pneumatization patterns of ethmoidal and sphenoid bones.
