Lateral Recess of the Sphenoid Sinus

Pneumatization of the sphenoid sinus can extend laterally, creating a lateral recess. Pneumatization can then further extend into the pterygoid process, the great wing of the sphenoid bone (as seen abvoe) or both. This can be clinically relevant, as surgical access to lesions in this lateral recess can be challenging.

Coronal images reveal projection of the sphenoid sinus sidewall beyond the foramen rotundum (r). The lateral recess extends into the greater wing of the sphenoid bone above the vidian canal (v) and below the foramen rotundum (r), separating the two. There may be normal side-to-side asymmetry of the vidian-rotundum distance.

The main differential consideration in an opacified sinus is an expansile or erosive process in the sphenoid sinus (e.g., mucoceles or polyps). The most specific evidence of such a process is gross sinus wall erosion and flattening or erosion of the rims of vidian canal or the foramen rotundum.

The patient above has bilateral lateral recesses, with the one on the right extending to the sphenoid wing. The patient also has multiple facial fractures.

References

• Giannetti AV, Guimarães RE, Santiago AP, Perpétuo FO, Machado MA. A tomographic study of the skull base in primary spontaneous cerebrospinal fluid leaks. Neuroradiology. 2011 Jul 8.
• Lewin JS, Curtin HD, Eelkema E, Obuchowski N. Benign expansile lesions of the sphenoid sinus: differentiation from normal asymmetry of the lateral recesses. AJNR Am J Neuroradiol. 1999 Mar;20(3):461-6.
• Tami TA. Surgical management of lesions of the sphenoid lateral recess. Am J Rhinol. 2006 Jul-Aug;20(4):412-6.