Background: Tertiary hyperparathyroidism is due to autonomous hyperfunction of parathyroid gland. Parathyroidectomy are usually performed in patients who are refractory to medical treatment, aiming to decrease serum parathyroid hormone level. Ultrasound plays role in pre-operative detection of the abnormal gland.
Objective: The purpose of the study was to describe ultrasonographic appearances of parathyroid gland hyperplasia in tertiary hyperparathyroidism.
Material and Method: The study was performed in retrospective design. Patients diagnosed as tertiary hyperparathyroidism with available pre-operative ultrasonography of the neck during May 2009 and Jan 2015, and had pathologic confirming hyperplasia were included into the study. Datas were collected for location, echogenicity, surface, margin, vascularization, cystic change and calcification.
Results: There were 28 patients with 58 parathyroid glands found on ultrasound in the study. The size of the gland was ranged from 0.6 to 3.5 cm. The most common ultrasonographic findings found on the study was well-defined hypoechoic lesion with peripheral vascularity.
Conclusion: Familiarity of the appearance of the abnormal parathyroid gland could facilitate radiologist to localize the lesion confidently.

Keywords: Ultrasonography, Tertiary hyperparathyroidism