This European expert consensus statement provides recommendations for the diagnosis and management of primary hyperparathyroidism (PHPT), chronic hypoparathyroidism in adults (HypoPT), and parathyroid disorders in relation to pregnancy and lactation. Specified areas of interest and unmet needs identified by experts at the second ESE Educational Program of Parathyroid Disorders (PARAT) in 2019, were discussed during two virtual workshops in 2021, and subsequently developed by working groups with interest in the specified areas. PHPT is a common endocrine disease. However, its differential diagnosing to familial hypocalciuric hypercalcemia (FHH), the definition and clinical course of normocalcemic PHPT, and the optimal management of its recurrence after surgery represent areas of uncertainty requiring clarifications. HypoPT is an orphan disease characterized by low calcium concentrations due to insufficient PTH secretion, most often secondary to neck surgery. Prevention and prediction of surgical injury to the parathyroid glands are essential to limit the disease-related burden. Long-term treatment modalities including the place for PTH replacement therapy and the optimal biochemical monitoring and imaging surveillance for complications to treatment in chronic HypoPT, need to be refined. The physiological changes in calcium metabolism occurring during pregnancy and lactation modify the clinical presentation and management of parathyroid disorders in these periods of life. Modern interdisciplinary approaches to PHPT and HypoPT in pregnant and lactating women and their newborns children are proposed. The recommendations on clinical management presented here will serve as background for further educational material aimed for a broader clinical audience, and were developed with focus on endocrinologists in training.

PC associates with severe primary hyperparathyroidism and must be suspected if calcium ≥1.77 mmol/l. The prevalence of CDC73 germline mutations in PC and APA in Finland is 6%. PC has distinct histopathological characteristics and its incidence has increased over the past decades.

All patients with primary hyperparathyroidism should undergo localization studies before reoperation, but it is not known which method is most accurate. The purpose of this prospective study was to compare the performance of planar scintigraphy with 123 I/ 99m Tc-sestamibi, 99m Tc-sestamibi SPECT (SPECT/CT), 11 C-methionine PET/CT, and selective venous sampling (SVS) in persistent primary hyperparathyroidism. Methods: Twenty-one patients referred for reoperation of persistent hyperparathyroidism were included and investigated with 123 I/ 99m Tc-sestamibi, SPECT/CT (n 5 19), 11 C-methionine PET/CT, and SVS (n 5 18) before reoperation. All patients had been operated on 1-2 times previously because of hyperparathyroidism. The results of the localization studies were compared with operative findings, histology, and biochemical cure. Results: Eighteen (86%) of 21 patients were biochemically cured. Nineteen parathyroid glands (9 adenomas, 1 atypical adenoma, and 9 hyperplastic glands) were removed from 17 patients, and 1 patient who was biochemically cured had an unclear histology result. The accuracy for localizing a pathologic parathyroid gland to the correct side of the neck was 59% (95% confidence interval [CI], 36%-79%) for 123 I/ 99m Tc-sestamibi, 19% (95% CI, 5%-42%) for SPECT/CT, 65% (95% CI, 43%-84%) for 11 C-methionine PET/CT, and 40% (95% CI, 19%-65%) for SVS (P , 0.01 for 123 I/ 99m Tc-sestamibi vs. SPECT/ CT). The corresponding accuracy for the correct quadrant or more specific site was 48% (95% CI, 27%-69%) for 123 I/ 99m Tc-sestamibi, 14% (95% CI, 3%-36%) for SPECT/CT, 61% (95% CI, 39%-80%) for 11 C-methionine PET/CT, and 25% (95% CI, 9%-49%) for SVS (P , 0.02 for 123 I/ 99m Tc-sestamibi vs. SPECT/CT). In the 3 patients not cured, preoperative 123 I/ 99m Tc-sestamibi and SPECT/CT remained negative, SVS was false predictive in all, and 11 C-methionine PET/CT in 1. 11 C-methionine PET/CT accurately revealed the pathologic gland in 4 of 8 (50%) patients with a negative 123 I/ 99m Tc-sestamibi scan result, all of whom were biochemically cured after reoperation. Conclusion: Planar scintigraphy with 123 I/ 99m Tc-sestamibi performs well in complicated primary hyperparathyroidism and is recommended as first-line imaging before reoperation. 11 C-methionine PET/CT provides valuable additional information if 123 I/ 99m Tc-sestamibi scan results remain negative. 99m Tc-sestamibi SPECT/CT and SVS provide no additional information, compared with the combined results of 123 I/ 99m Tcsestamibi and 11 C-methionine PET/CT imaging.Key Words: primary hyperparathyroidism; persistent; reoperation; 123 I/ 99m Tc-sestamibi; SPECT-CT; 11 C-methionine PET/CT; selective venous sampling; PTH Nucl Med 2013; 54:739-747 DOI: 10.2967/jnumed.112.109561 Pri mary hyperparathyroidism is a common endocrine disease, with a peak incidence in women aged 50-60 y (1). It is explained by a single parathyroid adenoma in 80%-85% of patients, double adenomas in about 4%, and parathyroid hyperplasia in 15%-20% of cases. Parathyroid carcinoma is...