In patients with sporadic PHPT, the rate of persistence after initial PTx is 7% and that of recurrence none. In the case of persistent PHPT, the sensitivity of the widely used, non-invasive Tc99m... Show moreIn patients with sporadic PHPT, the rate of persistence after initial PTx is 7% and that of recurrence none. In the case of persistent PHPT, the sensitivity of the widely used, non-invasive Tc99m-MIBI-SPECT imaging technique is decreased and is significantly lower than that of the invasive technique of selective venous sampling for PTH. Chronic excess of PTH has a catabolic effect on bone, leading to mineral depletion of bone. Patients with pre-operative radiological signs of severe PTH-associated bone disease are at risk of developing hungry bone syndrome after surgery, which may be prevented by pre-operative treatment with bisphosphonates and 1,25(OH)2D. PTH inhibits sclerostin production and stimulates FGF23 production, presumably to counterbalance its own actions on bone and on 1,25(OH)2D, resulting in novel feedback loops. In contrast to sporadic PHPT, recurrent PHPT does occur in patients with parathyroid carcinoma. In these patients, downregulation of CASR, HRPT2/CDC73 mutations and global loss of parafibromin are strong negative determinants of the disease-free survival and overall survival. Recent progresses in surgical and medical treatment of patients with parathyroid carcinoma have made it possible to secure longer survival, even in patients with tumors demonstrating 2 of the 3 identified molecular negative prognostic factors. Show less