Answer
The parathyroid glands are usually found in the neck behind the thyroid glands. However, the actual location of the four parathyroids varies. In a small number of cases the pathyroids may be found below the jaw all the way into the thorax. The lower two parthyroids may in a small number of cases follow the thymus on its migration into the chest cavity . That is where the surgeon should look for the hidden, but evident, parathyroid tumor.
Work Step by Step
During embryogenesis, organs migrate or change positions in the developing embryo and fetus. The upper thyroids are associated with the thyroid gland, and the lower parathyroids are associated with the thymus gland. The thyroid gland migrates posteriorly, but remains in the neck region; usually, so do the four small parathyroids. However, in a small percentage of cases, the lower parathyroids, which are embryologically associated with the thymus, migrate with the thymus into the thoracic cavity. In such a case the lower parathyroids are usually found just behind the manubrium of the breast bone. That is where the surgeon should look for Mr. Neis' parathyroid tumor.
