Mild Primary Hyperparathyroidism: A Literature Review

The biochemical profile of classic primary hyperparathyroidism (pHPT) consists of both elevated calcium and parathyroid hormone levels. The standard of care is parathyroidectomy unless prohibited by medical comorbidities. Because more patients are undergoing routine bone density evaluation and neck imaging studies for other purposes, there is a subset of people identified with a biochemically mild form of the pHPT that expresses itself as either elevated calcium or parathyroid hormone levels. These patients often do not fall into the criteria for operation based on the National Institutes of Health consensus guidelines, and they can present a challenge of diagnosis and management. The purpose of this paper is to review the available literature on mild pHPT in an effort to better characterize this patient population and to determine whether patients benefit from parathyroidectomy. Evidence suggests that there are patients with mild pHPT who have overt symptoms that are found to improve after parathyroidectomy. There is also a group of patients with biochemically mild pHPT who are found to progress to classic pHPT over time; however, it is not predictable which group of patients this will be. Early intervention for this group with mild pHPT may prevent progression of bone, psychiatric, and renal complications, and parathyroidectomy has proven safe in appropriately selected patients at high volume centers.