Ectopic Parathyroid Adenoma in the Carotid Sheath.

Primary hyperparathyroidism is predominantly caused by a single parathyroid adenoma. Knowledge of normal and ectopic locations of parathyroid glands is crucial to help guide surgeons who plan targeted unilateral parathyroidectomy to reduce surgical time and risk. We describe a female patient with clinical primary hyperparathyroidism who underwent a failed initial parathyroidectomy, with subsequent imaging localizing an ectopic parathyroid adenoma in the carotid sheath.