An unusual emissary foramen of the temporal bone

Emissary foramina (EF) provide venous connections between intracranial dural sinuses and extracranial venous networks. While common EF are well described, their variants are underrecognized. Identifying unusual EF is clinically important, as they may mimic pathology on imaging, provide routes for infection, or increase bleeding risk during skull base and temporal bone surgery. This study reports a unique EF of the temporal bone detected through imaging.

A retrospective review of a high-resolution computed tomography (CT) scan of a 64-year-old male patient was performed using multiplanar reconstructions and three-dimensional reconstructions (slice thickness: 0.6 mm).

A distinct foramen, measuring 3.15 mm in diameter, was identified in the right temporal bone, 9.2 mm superior to the zygomatic arch and 1.4 mm lateral to the middle meningeal artery groove. It was clearly separate from the postglenoid foramen and absent contralaterally. Its topography suggests a venous connection between the extracranial pterygoid venous plexus and intracranial venous channels, resembling but not identical to previously described postglenoid or squamosal foramina.

This case expands the morphological spectrum of temporal bone EF. Recognition of such variants is essential to avoid misinterpretation on imaging, prevent misdiagnosis, and anticipate potential surgical complications such as unexpected bleeding or venous injury. Detailed radiologic evaluation should be emphasized in skull base surgery planning and radiology reporting.