Aberrant course of the dominant superior thyroid artery in a patient undergoing a total thyroidectomy

We present the case of a 38-year-old Caucasian female who underwent a total thyroidectomy for papillary thyroid carcinoma. We identified a large anomalous superior thyroid artery (STA) that emerged as a second branch of the external carotid artery and entered the thyroid isthmus superficial to the right sternothyroid muscle. In this case report, we discuss the embryology of the thyroid gland as well as the possible embryological basis for this unusual course of the STA. In doing so, we aim to improve recognition of the potential vascular variations in the thyroid gland, in turn aiding surgeons in the prevention of unnecessary complications and providing insight into the embryologic development of this organ