Locations of parathyroid glands

Most patients have four parathyroid glands: two superior and two inferior glands. The terms "superior" and "inferior" refer to a gland's embryologic origin, rather than the gland's location in the neck. The parathyroids are usually in close association with the thyroid gland. The superior parathyroid glands are usually 1 to 2 centimeters cranial to the junction of the recurrent laryngeal nerve with the inferior thyroid artery and within 1 centimeter of the entry point for the recurrent laryngeal nerve into the ligament of Berry and the cricoid cartilage. Superior parathyroid glands can be undescended or can be parapharyngeal, retropharyngeal, or retrotracheal within the middle cervical/mediastinal compartment. Enlarged parathyroid glands can travel straight down the tracheoesophageal groove or the retropharyngeal space into the chest. The two inferior parathyroid glands reside in the anterior mediastinal compartment, anterior to the recurrent laryngeal nerve. They are most often found in the thyrothymic tract or just inside the thyroid capsule on the inferior portion of the thyroid lobes.