parathyroid adenoma is one of the most common causes of primary hyperparathyroidism.1 The occurrence of parathyroid adenomas outside the parathyroid gland is usually explained by their embryonic development. Therefore, the abnormal parathyroid gland can occur in any part of the pathway of parathyroid embryonic development.2primary hyperparathyroidism is 3 times more common in womenand occurs at an average age of 60 years.3 The incidence and prevalence primary hyperparathyroidism areabout 1/1000 and 3/1000 in the normal population respectively. 3 Primary hyperparathyroidism is due to single adenoma(85-85%), hyperplasia (10-20%), carcinoma (1%), and up to 20% of theparathyroid glands may be outside of the anatomical location.
4The most common site of the ectopic parathyroid glandis in the mediastinum.2 clinical manifestation in patients with primaryhyperparathyroidism depending on serum calcium levels,such as bone pain, depression, anxiety, fatigue, polyuria, polydipsia, musclecramp, and constipation.Benign tumors are not detectable in the routinephysical examination and are diagnosed based on laboratory findings andimaging.4.
After neck exploration, ectopic tumors and several other reasonssuch as disease recurrence or surgical site residue can be responsible forpersistent hyperparathyroidisms.Due to these challenges, Anatomical studies arerecommended before re-surgery. In managing parathyroid adenoma recurrence after previous surgery, thecareful examination of previous imaging, operational and pathology notes, ultrasound and 99mTc-Sestamibi scan are required.
If thelocation of the tumor remains uncertain, cross-sectional imaging(eg, CT or MRI)should be taken.2 The sensitivity of ultrasonography and Tc-99m sestamibi scan in the discovery of adenoma is 60-90% and70-80%respectively. The highest sensitivity test for localization of parathyroidtumors is 99m sestamibi scan with Single-Photon Emission Computerized Tomography(SPECT) about 87%.5