Parathyroid adenoma versus primary hyperparathyroidism

This is a narrative review of literature. We focus on the issue of identifying a parathyroid adenoma without anomalies of function (non-functioning parathyroid adenoma) which is incidentally detected or not, via routine neck ultrasound or through advanced imaging techniques which are mostly performed for other conditions (like assessment of a non-parathyroid oncological condition or emergencies – related neck exploration). The traditional diagnostic of primary hyperparathyroidism is exclusively a biological one based on high calcium and parathormone (PTH), and only a second step of assessment actually involves the localization procedures. However, the detection of a parathyroid tumor does not necessarily mean that it is associated with an over-secretion of PTH. Ultrasound is usually followed by Tc Sestamibi scintigram and/or computed tomography is order to refer the patient to parathyroidectomy in cases with biological confirmation of primary or renal hyperparathyroidism; yet, in cases with non-functioning profile, there is no clear indication of further imaging exploration. In conclusion, the identification of a parathyroid adenoma is rarely associated with a normal parathyroid function and this entity, which most probably is an incidentaloma, is not a subject of particular guidelines yet. Whether it is necessary to continue with other imaging techniques as typically seen in primary hyperparathyroidism is still an open issue, and so is the panel of indications to perform its surgical removal instead of serial follow-up.