[A clinically relevant variation of the superior thyroid artery].

Usually the superior thyroid artery is a branch of the external carotid artery. During a functional neck dissection in order to remove a metastasis of a tongue cancer we observed a variation of the origin of the vessel that was interesting from the surgeon's point of view. The artery rose from the A. carotis communis 3.5 cm below the bifurcation of the common carotid artery. Normally in this region no vessels leave the common carotid artery and therefore the knowledge of such variations is important for the exact identification of the neck vessels during surgery to avoid a fatal mix-up with the internal carotid artery.