A Unique Emissary Foramen: The Far Anterior Paracondylar Foramen.

Emissary foramina (EF) transmit emissary veins interconnecting extracranial veins with intracranial venous plexuses. A unique EF will be presented. A dried male adult skull was further investigated due to its unique morphology. On the left side, an accessory EF was observed inferior to the inferior petrosal sinus groove (IPSG) in the anterior paracondylar region, with 1.59 mm (height) x 2.87 mm (width). The IPSG morphology was an incomplete tunnel with a foramen into the petro-occipital fissure. Also, the jugular foramen (JF) had a complete bony septation that formatted 2 distinct compartments. The novel accessory EF identified in the present case probably transmits an emissary vein interconnecting the inferior petrosal sinus with the anterior condyle confluence. Therefore, it could be defined as "far anterior paracondylar foramen." Knowledge of skull base anatomy is paramount when planning regional interventions because variant structures may be hidden.