Tubercle Of Zuckerkandl -

The TZ arises from the fusion of the ultimobranchial bodies (derived from the fourth pharyngeal pouch) and the median thyroid process. During embryogenesis, the thyroid gland descends from the floor of the pharynx. As it fuses with the ultimobranchial bodies, the lateral and posterior aspects of the gland develop into what Zuckerkandl termed the "tubercle."

The tubercle is located on the posterior surface of the thyroid lobe, typically just inferior to the insertion of the inferior thyroid artery. It projects posteriorly or laterally and varies significantly in size. tubercle of zuckerkandl