Umeh R, Loukas M, Oskouian RJ, Tubbs RS.Ectopic arachnoid granulation involving a rare intracranial venous sinus variant.Folia Morphol (Warsz). 2016 Nov 4. doi: 10.5603/FM.a2016.0062.
Arachnoid granulations are hypertrophied arachnoid villi, which extend from the subarachnoid space into the venous system and aid in the passive filtration and reabsorption of cerebrospinal fluid. These macroscopic structures have been described in various locations, with the transverse and sigmoid sinuses seen as normal variant s on imaging.
Here we present the occurrence of an enlarged arachnoid granulation at the foramen rotundum where a variant intracranial venous sinus was identified during routine dissection.
Variations, such as the one described herein, should be recognized by those who operate or interpret images of the skull base.