The Superior Trajectory of the Lingual Artery over the Hypoglossal Nerve: A Morphological Case Report and Focused Review of Neurovascular Inversion in the Carotid Triangle

Introduction: Accurate knowledge of the external carotid artery (ECA) anatomy is essential for head and neck surgery, interventional procedures, and imaging interpretation. Although its branching pattern is classically described as relatively constant, clinically relevant anatomical variations are frequently encountered. Cadaveric dissection remains fundamental for identifying rare vascular configurations. Materials and Methods: During an anatomical teaching dissection of a 72-year-old male cadaver, a right-sided lateral cervicotomy was performed to expose the carotid sheath. After mobilisation of the sternocleidomastoid muscle, the ECA and its proximal branches were skeletonised, allowing detailed three-dimensional assessment of their origin, calibre, and neurovascular relationships. Results: The superior thyroid artery originated from the proximal segment of the external carotid artery, in close proximity to the carotid bifurcation. The main anatomical finding was a lingual artery of relatively small initial calibre exhibiting an atypical superior trajectory: after its origin, it crossed superior to the hypoglossal nerve before continuing toward the tongue. This configuration differs from classical descriptions and modified the anatomical arrangement of Beclard’s and Pirogoff’s triangles, creating a potential site of close neurovascular contact. Conclusions: This cadaveric study describes a rare trajectory-based variant of the external carotid artery characterised by a lingual artery crossing superior to the hypoglossal nerve. Awareness of such rare patterns is essential for improving anatomical interpretation and enhancing surgical safety in the head and neck regioN.