Persistent primary hyperparathyroidism caused by adenomas identified in pharyngeal or adjacent structures

Abnormalities in the normal migration of the parathyroid glands during embryological development of the head and neck may result in considerable variability in the location of parathyroid tissue. Ectopic parathyroid adenomas present diagnostic and technical challenges and are frequently the cause of persistent primary hyperparathyroidism (HPT) after unsuccessful initial parathyroid surgery. We report a series of eight patients with persistent primary HPT who had adenomas in rare and unusual locations associated with various pharyngeal structures. Four were located within the epineurium of the vagus nerve at or above the level of the carotid bifurcation, and four were located within the paranasopharyngeal space or oropharynx. Noninvasive and invasive preoperative imaging studies were crucial in localizing the neoplasms in these patients and permitted the use of a direct surgical approach, resulting in cure in all patients and a low complication rate. The location of parathyroid glands in high pharyngeal and cervical structures is a consequence of anomalous or arrested descent through developing pharyngeal structures and illustrates the remarkable spectrum of ectopic parathyroid adenomas that occur secondary to this phenomenon.