What is the best treatment primary hyperparathyroidism but negative preoperative localization studies?
Surgery! Patient age < 50 years warrants parathyroidectomy. Remember, failure to localize an abnormal parathyroid on imaging has nothing to do with whether or not a patient has HPT or whether or not the patient should undergo surgery. The sensitivity of preoperative localization studies is not perfect, and they fail to localize an abnormal parathyroid approximately 15% of the time. Although multiglandular disease is more common when preoperative localization studies are negative, most patients with negative localization will still turn out to have a single adenoma as the cause of their HPT. The success rate of surgery, if performed by an experienced surgeon, is still high (> 90%–95%) when preoperative localization is negative.