A Rare Anatomical Relationship of Spinal Accessory Nerve to Internal Jugular Vein

Abstract

A patient with squamous cell carcinoma of right retromolar area of the mandible and undergoing a staging neck dissection was noted to have a unique relationship of the internal jugular vein and spinal accessory nerve. At the upper end of the dissection (level II, Memorial Sloan-Kettering classification), the spinal accessory nerve was observed to pass directly through the internal jugular vein. Although previously described only once in the literature, this finding may be encountered by other surgeons who operate in this area and it is important that these anatomical variations are borne in mind to prevent inadvertent injury. To our knowledge, this must be the first case reported from India.