Superior and middle thyroid arteries arising from the common carotid artery.

We report a rare case of a left middle thyroid artery in a 71-year-old male cadaver. The middle thyroid artery arose from the anterior surface of the left common carotid artery. This artery ran anteroinferiorly and then bifurcated as it entered the lower lateral part of the left thyroid lobe. Both the right and left superior thyroid arteries arose from the common carotid arteries below the carotid bifurcation. The presence of a middle thyroid artery may cause unexpected bleeding during thyroid or neck surgery, and this rare variation needs to be kept in mind during the surgery.