Parathyroid Adenoma within the Carotid Sheath

Ectopic parathyroid adenoma is an uncommon cause of primary hyperparathyroidism. Apart from the usually described sites of ectopic parathyroid adenoma, anecdotal case reports of undescended parathyroid adenoma along the carotid artery have been described.

We report a rare case of a 4 cm large parathyroid adenoma within the carotid sheath.

A 27-year-old lady presented with severe bony pains, history of height loss, fracture of left shaft femur following trivial trauma and renal calculi. On evaluation she had hypercalcemia with elevated iPTH suggestive of primary hyperparathyroidism. Ultrasound of neck and 99mTc sestamibi SPECT/CT incorrectly localised the lesion as right inferior parathyroid adenoma leading to a failed initial surgery. Later CECT of the neck identified adenoma posterior to right common carotid artery which was confirmed on repeat surgery and the patient was cured.

Ectopic parathyroid adenomas are both difficult to localise and are a common cause of failed initial parathyroid surgery. Surgeons should exercise caution while removing a visually normal parathyroid gland. In case of any discordance with the pre-operative localization, a meticulous systematic dissection using the conventional approach should be performed and the possibility of an undescended gland in the carotid sheath should be considered.