Surgical Anatomy of the Parathyroid Glands

Abstract

The superior and inferior parathyroid glands are derived from the fourth and third pharyngeal pouches, respectively. This accounts for their differences in terms of variability in anatomic location. While most parathyroid glands can be found in their normal anatomic position, there remains a significant percentage of supernumerary glands and ectopic glands, which not uncommonly reside in the mediastinum. Understanding the possible sites of ectopic parathyroid glands will help guide the surgeon during parathyroid exploration.