2021 Jul 18. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–.
Normocalcemic primary hyperparathyroidism (nPHPT) is a new phenotype of sporadic primary hyperparathyroidism where elevated PTH is the result of autonomous hypersecretion of one or more parathyroid glands, and serum calcium(Ca) is consistently normal.
In normocalcemic secondary hyperparathyroidism (nSHPT), the PTH elevation is a reaction to a low calcium stimulus from various causes. The PTH remains elevated as long as the low calcium stimulus persists and returns to normal as soon as it is removed.
It is important to first exclude (nSHPT) by a thorough history, physical, and directed laboratory investigations before embarking on a diagnosis of nPHPT, as medical treatment is directed at the causes of the low calcium stimuli in nSHPT and the treatment of nPHPT is directed at the abnormal parathyroid(s); parathyroidectomy (PTX) may ameliorate morbidity in nPHPT.
In this article, the latest literature describing the etiology, epidemiology, pathophysiology, evaluation, treatment strategies of nPHPT, and the differential diagnosis of pertinent nSHPT are reviewed.