Radiological Identification of an Arcuate Anterior Jugular Vein: A Rare Variant in Head and Neck Venous Anatomy

The head and neck veins often show considerable variation identifiable by modern imaging. We present a case of a rare anterior jugular vein (AJV) variation in a 51-year-old female, observed on contrast-enhanced computed tomography. Normally, the AJV runs along the midline beneath the chin, turning laterally near the clavicle to drain into the external jugular vein. In this case, however, the left AJV curved rightward at the hyoid bone midline and joined the right AJV, forming a loop around the submandibular gland. Along the superior and inferior gland borders, tributaries from the hyoid, submandibular, and facial veins contributed to the arch. This unusual right-left connection corresponds to the arcuate AJV (arcAJV), a very rare anatomic variant. The right AJV was larger in diameter, and both drained into the subclavian veins. Awareness of the arcAJV is clinically important for head and neck surgeons to prevent iatrogenic injury.