Single gland excision for MEN1-associated primary hyperparathyroidism

Evaluation and Surgical Management of Multiple Endocrine Neoplasias

Multiple endocrine neoplasia (MEN) syndromes are rare autosomal dominant diseases that are associated with a mixture of both endocrine and non-endocrine tumors. Traditionally, there are 2 types of MEN that have unique clinical associations: MEN 1 (parathyroid hyperplasia, pancreatic neuroendocrine tumors, and pituitary tumors) and MEN 2 (medullary thyroid carcinoma and pheochromocytoma), which is further classified into MEN 2A (adds parathyroid adenomas) and 2B (adds ganglioneuromas and marfanoid habitus). Many of the endocrine tumors are resected surgically, and the pre, intra, and postoperative management strategies used must take into account the high recurrence rates asscioated with MEN tumors.

Recurrence After Surgery for Primary Hyperparathyroidism in 517 Patients With Multiple Endocrine Neoplasia Type 1: An Association Francophone de Chirurgie Endocrinienne and Groupe d'étude des Tumeurs Endocrines study

OBJECTIVE

To assess recurrence according to the type of surgery for primary hyperparathyroidism (pHPT) in multiple endocrine neoplasia type 1 ( MEN1 ) patients and to identify the risk factors for recurrence after the initial surgery.

BACKGROUND

In MEN1 patients, pHPT is multiglandular, and the optimal extent of initial parathyroid resection influences the risk of recurrence.

METHODS

MEN1 patients who underwent initial surgery for pHPT between 1990 and 2019 were included. Persistence and recurrence rates after less than subtotal parathyroidectomy (LTSP) and subtotal parathyroidectomy (STP) were analyzed. Patients with total parathyroidectomy with reimplantation were excluded.

RESULTS

Five hundred seventeen patients underwent their first surgery for pHPT: 178 had LTSP (34.4%) and 339 STP (65.6%). The recurrence rate was significantly higher after LTSP (68.5%) than STP (45%) ( P < 0.001). The median time to recurrence after pHPT surgery was significantly shorter after LTSP than after STP: 4.25 (1.2-7.1) versus 7.2 (3.9-10.1) years ( P < 0.001). A mutation in exon 10 was an independent risk factor of recurrence after STP (odds ratio = 2.19; 95% CI: 1.31; 3.69; P = 0.003). The 5 and 10-year recurrent pHPT probabilities were significantly higher in patients after LTSP with a mutation in exon 10 (37% and 79% vs 30% and 61%; P = 0.016).

CONCLUSIONS

Persistence, recurrence of pHPT, and reoperation rate are significantly lower after STP than LTSP in MEN1 patients. Genotype seems to be associated with the recurrence of pHPT. A mutation in exon 10 is an independent risk factor for recurrence after STP, and LTSP may not be recommended when exon 10 is mutated.

Primary hyperparathyroidism in patients with multiple endocrine neoplasia type 1: Impact of genotype and surgical approach on long-term postoperative outcomes

BACKGROUND

Protein-truncating germline pathogenic variants in the N- and C-terminal exons (2, 9, and 10) of the MEN1 gene may be associated with aggressive pancreatic neuroendocrine tumors. However, the impact of these variants on parathyroid disease is poorly understood. We sought to investigate the effects of genotype and surgical approach on clinical phenotype and postoperative outcomes in patients with multiple endocrine neoplasia type 1 (MEN1)-related primary hyperparathyroidism.

METHODS

We identified patients with MEN1 evaluated at our institution from 1985 to 2020 and stratified them by genotype, (truncating variants in exons 2, 9, or 10, or other variants), and index surgical approach, (less-than-subtotal parathyroidectomy [

RESULTS

Of the 209 patients we identified, primary hyperparathyroidism was diagnosed in 194 (93%) and at a younger median age in those with truncating exon 2, 9, or 10 variants compared with other variants (27 years vs 31 years; P = .006). Median disease-free survival was significantly worse in patients who underwent

CONCLUSION

The MEN1 genotype may affect the age of onset of primary hyperparathyroidism and the time to recurrence after surgery. Collapse

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MESH Headings

• Humans
• Adult
• Multiple Endocrine Neoplasia Type 1/complications
• Multiple Endocrine Neoplasia Type 1/genetics
• Multiple Endocrine Neoplasia Type 1/surgery
• Hyperparathyroidism, Primary/genetics
• Hyperparathyroidism, Primary/surgery
• Hyperparathyroidism, Primary/epidemiology
• Neoplasm Recurrence, Local/surgery
• Parathyroidectomy/adverse effects
• Hypoparathyroidism/etiology
• Genotype

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Grants Collapse

Affiliation(s)

Omair A Shariq Department of Surgery, Mayo Clinic, Rochester, MN.
Vitor B Abrantes Department of Surgery, Mayo Clinic, Rochester, MN
Lauren Y Lu Department of Surgery, Mayo Clinic, Rochester, MN
Peter J Tebben Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, Rochester, MN
Trenton M Foster Department of Surgery, Mayo Clinic, Rochester, MN
Benzon M Dy Department of Surgery, Mayo Clinic, Rochester, MN
Melanie L Lyden Department of Surgery, Mayo Clinic, Rochester, MN
William F Young Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, Rochester, MN
Travis J McKenzie Department of Surgery, Mayo Clinic, Rochester, MN

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Clinical profile and treatment outcomes among patients with sporadic and multiple endocrine neoplasia syndrome-related primary hyperparathyroidism

OBJECTIVE

Accurate demarcation between multiple endocrine neoplasia, type 1 (MEN1)- related primary hyperparathyroidism (MPHPT) and sporadic PHPT (SPHPT) is important to plan the management of primary parathyroid disease and surveillance for other endocrine and nonendocrine tumours. The objective of this study is to compare the clinical, biochemical and radiological features and surgical outcomes in patients with MPHPT versus SPHPT and to identify the predictors of MEN1 syndrome in PHPT.

DESIGN, PATIENTS AND MEASUREMENTS

This was an ambispective observationalstudy involving 251 patients with SPHPT and 23 patients with MPHPT evaluated at the endocrine clinic of All India Institute of Medical Sciences, New Delhi, India between January 2015 and December 2021.

RESULTS

The prevalence of MEN1 syndrome among patients with PHPT was 8.2% and a genetic mutation was identified by Sanger sequencing in 26.1% of patients with MPHPT. Patients with MPHPT were younger (p < .001), had lower mean serum calcium (p = .01) and alkaline phosphatase (ALP; p = .03) levels and lower bone mineral density (BMD) Z score at lumbar spine (p < .001) and femoral neck (p = .007). The prevalence of renal stones (p = .03) and their complications (p = .006) was significantly higher in MPHPT group. On multivariable analysis, factors predictive of MPHPT were hyperplasia on histopathology [OR 40.1, p < .001], ALP levels within reference range [OR 5.6, p = .02] and lumbar spine BMD [OR 0.39 per unit increase in Z score, p < .001].

CONCLUSIONS

Patients with MPHPT have more severe, frequent and early onset of bone and renal involvement despite milder biochemical features. A normal serum ALP, low BMD for age and gender at lumbar spine and histopathology evidence of hyperplasia are predictive factors for MEN1 syndrome in PHPT.

Ultrasound-guided microwave ablation in the treatment of recurrent primary hyperparathyroidism in a patient with MEN1: a case report

Background

Multiple endocrine neoplasia type 1 (MEN1) is an inherited endocrine syndrome caused by the mutation in the tumor suppressor gene MEN1. The recurrence rate of primary hyperparathyroidism (PHPT) in patients with MEN1 after parathyroidectomy remains high, and the management of recurrent hyperparathyroidism is still challenging.

Case presentation

We reported a 44-year-old woman with MEN1 combined with PHPT who was diagnosed through genetic screening of the patient and her family members. After parathyroidectomy to remove one parathyroid gland, the patient suffered from persistent high levels of serum calcium and parathyroid hormone, which returned to normal at up to 8 months after ultrasound-guided microwave ablation (MWA) for bilateral parathyroid glands, suggesting an acceptable short-term prognosis.

Conclusion

Ultrasound-guided MWA for parathyroid nodules may be an effective therapeutic strategy for recurrent PHPT in MEN1 patients.

Molecular and Clinical Spectrum of Primary Hyperparathyroidism

Recent data suggest an increase in the overall incidence of parathyroid disorders, with primary hyperparathyroidism (PHPT) being the most prevalent parathyroid disorder. PHPT is associated with morbidities (fractures, kidney stones, chronic kidney disease) and increased risk of death. The symptoms of PHPT can be nonspecific, potentially delaying the diagnosis. Approximately 15% of patients with PHPT have an underlying heritable form of PHPT that may be associated with extraparathyroidal manifestations, requiring active surveillance for these manifestations as seen in multiple endocrine neoplasia type 1 and 2A. Genetic testing for heritable forms should be offered to patients with multiglandular disease, recurrent PHPT, young onset PHPT (age ≤40 years), and those with a family history of parathyroid tumors. However, the underlying genetic cause for the majority of patients with heritable forms of PHPT remains unknown. Distinction between sporadic and heritable forms of PHPT is useful in surgical planning for parathyroidectomy and has implications for the family. The genes currently known to be associated with heritable forms of PHPT account for approximately half of sporadic parathyroid tumors. But the genetic cause in approximately half of the sporadic parathyroid tumors remains unknown. Furthermore, there is no systemic therapy for parathyroid carcinoma, a rare but potentially fatal cause of PHPT. Improved understanding of the molecular characteristics of parathyroid tumors will allow us to identify biomarkers for diagnosis and novel targets for therapy.

[Special features of the diagnostics and treatment of hereditary primary hyperparathyroidism]

Between 2% and 10% of patients with primary hyperparathyroidism (pHPT) are diagnosed with hereditary forms of primary hyperparathyroidism (hpHPT). They are more prevalent in younger patients before the age of 40 years, in patients with persistence or recurrence of pHPT and pHPT patients with multi-glandular disease (MGD). The various forms of hpHPT diseases can be classified into four syndromes, i.e., hpHPT associated with diseases of other organ systems, and four diseases that are confined to the parathyroid glands. Approximately 40% of patients with hpHPT suffer from multiple endocrine neoplasia type 1 (MEN-1) or show germline mutations of the MEN‑1 gene. Currently, germline mutations that lead to a specific diagnosis in patients with hpHPT have currently been described in 13 different genes, which enables a clear diagnosis of the disease; however, a clear genotype-phenotype correlation does not exist, even though the complete loss of a coded protein (e.g. due to frame-shift mutations in the calcium sensing receptor, CASR) often leads to more severe clinical consequences than merely a reduced function of the protein (e.g. due to point mutation). As the various hpHPT diseases require different treatment approaches, which do not correspond to that of sporadic pHPT, a clear definition of the specific form of hpHPT must always be strived for. Therefore, before surgery of a pHPT with clinical, imaging or biochemical suspicion of hpHPT, genetic proof or exclusion of hpHPT is necessary. The differentiated treatment approach for hpHTP can only be defined by taking the clinical and diagnostic results of all the abovenamed findings into account.

Surgical Aspects of Primary Hyperparathyroidism

Parathyroidectomy (PTX) is the treatment of choice for symptomatic primary hyperparathyroidism (PHPT). It is also the treatment of choice in asymptomatic PHPT with evidence for target organ involvement. This review updates surgical aspects of PHPT and proposes the following definitions based on international expert consensus: selective PTX (and reasons for conversion to an extended procedure), bilateral neck exploration for non-localized or multigland disease, subtotal PTX, total PTX with immediate or delayed autotransplantation, and transcervical thymectomy and extended en bloc PTX for parathyroid carcinoma. The systematic literature reviews discussed covered (i) the use of intraoperative PTH (ioPTH) for localized single-gland disease and (ii) the management of low BMD after PTX. Updates based on prospective observational studies are presented concerning PTX for multigland disease and hereditary PHPT syndromes, histopathology, intraoperative adjuncts, localization techniques, perioperative management, "reoperative" surgery and volume/outcome data. Postoperative complications are few and uncommon (<3%) in centers performing over 40 PTXs per year. This review is the first global consensus about surgery in PHPT and reflects the current practice in leading endocrine surgery units worldwide. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Update on the clinical management of multiple endocrine neoplasia type 1

This review provides an overview of novel insights in the clinical management of patients with Multiple Endocrine Neoplasia Type 1, focusing on the last decade since the last update of the MEN1 guidelines. With regard to Diagnosis: Mutation-negative patients with 2/3 main manifestations have a different clinical course compared to mutation-positive patients. As for primary hyperparathyroidism: subtotal parathyroidectomy is the initial procedure of choice. Current debate centres around the timing of initial parathyroidectomy as well as the controversial topic of unilateral clearance in young patients. For duodenopancreatic neuroendocrine tumours (NETs), the main challenge is accurate and individualized risk stratification to enable personalized surveillance and treatment. Thymus NETs remain one of the most aggressive MEN1-related tumours. Lung NETs are more frequent than previously thought, generally indolent, but rare aggressive cases do occur. Pituitary adenomas are most often prolactinomas and nonfunctioning microadenomas with an excellent prognosis and good response to therapy. Breast cancer is recognized as part of the MEN1 syndrome in women and periodical screening is advised. Clinically relevant manifestations are already seen at the paediatric age and initiating screening in the second decade is advisable. MEN1 has a significant impact on quality of life and US data show a significant financial burden. In conclusion, patient outcomes have improved, but much is still to be achieved. For care tailored to the needs of the individual patient and improving outcomes on an individual basis, studies are now needed to define predictors of tumour behaviour and effects of more individualized interventions.

Less Than Subtotal Parathyroidectomy for Multiple Endocrine Neoplasia Type 1 Primary Hyperparathyroidism: A Systematic Review and Meta-Analysis

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN1)-associated primary hyperparathyroidism (pHPT) is classically associated with an asymmetric and asynchronous parathyroid involvement. Subtotal parathyroidectomy (STP), which is currently the recommended surgical treatment, carries a high risk of permanent hypoparathyroidism. The results of less than subtotal parathyroidectomy (LSTP) are conflicting, and its place in this setting is still a matter of debate. The aim of this study was to identify the place of LSTP in the surgical management of patients with MEN-associated pHPT.

METHODS

A systematic literature review was conducted in accordance with PRISMA and MOOSE guidelines, for studies comparing STP and LSTP for MEN1-associated pHPT. The results of the two techniques, regarding permanent hypoparathyroidism, persistent hyperparathyroidism and recurrent hyperparathyroidism were computed using pairwise random-effect meta-analysis.

RESULTS

Twenty-five studies comparing STP and LSTP qualified for inclusion in the quantitative synthesis. In total, 947 patients with MEN1-associated pHPT were allocated to STP (n = 569) or LSTP (n = 378). LSTP reduces the risk of permanent hypoparathyroidism [odds ratio (OR) 0.29, confidence interval (CI) 95% 0.17-0.49)], but exposes to higher rates of persistent hyperparathyroidism [OR 4.60, 95% CI 2.66-7.97]. Rates of recurrent hyperparathyroidism were not significantly different between the two groups [OR 1.26, CI 95% 0.83-1.91].

CONCLUSIONS

LSTP should not be abandoned and should be considered as a suitable surgical option for selected patients with MEN1-associated pHPT. The increased risk of persistent hyperparathyroidism could improve with the emergence of more efficient preoperative localization imaging techniques and a more adequate patients selection.

Multiple endocrine neoplasia type 1 or 4: detection of hyperfunctioning parathyroid glands with 18F-fluorocholine PET/CT. Illustrative cases and pitfalls

¹⁸F-fluorocholine (FCH) PET/CT is now well established to detect the hyperfunctioning parathyroid glands (HFPTG) in a case of sporadic primary hyperparathyroidism (pHPT), but only limited evidence is available about the utility of FCH PET/CT to detect the HFPTG in patients with multiple endocrine neoplasia (MEN) type 1 or 4. The pHPT in this context frequently consists in a multiglandular disease with small hyperplastic glands rather than adenomas, which is challenging for imaging modalities. The data of patients with MEN1 or MEN4 after parathyroidectomy referred to FCH PET/CT for presurgical localization of HFPTG were retrospectively reviewed, including follow-up after parathyroidectomy, in search for diagnostic performance and for potential pitfalls. In the present cohort, 16 patients referred to FCH PET/CT as part of their initial pHPT work-up were subsequently operated, 44 abnormal parathyroid glands (PT) were resected, of which 32 (73%) had been detected on FCH PET/CT and 2 considered as equivocal foci. Nine patients referred to FCH PET/CT for recurrent pHPT who were subsequently operated, 14 abnormal PT were resected, all had been detected on FCH PET/CT. FCH PET/CT permitted a unilateral approach for PTx in 4 of them. In one patient with MEN4 and pHPT, the HFPTG could not be visualized on FCH PET/CT but was localized by ultrasonography. Several causes of false positive or false negative results, incidental finding and pitfalls are listed and discussed. FCH PET/CT has a positive benefit/risk ratio in the detection of HFPTG in case of MEN1 (the data in MEN4 being currently very limited) with the most effective detection rate of current imaging modalities for HFPTG, few pitfalls, and an adequate impact on patient management compared to sesta MIBI SPECT and ultrasonography.

New therapies for patients with multiple endocrine neoplasia type 1

In 1953, for the first time, Paul Wermer described a family presenting endocrine gland neoplasms over several generations. The transmission was autosomal dominant and the penetrance was high. Forty years later in 1997, the multiple endocrine neoplasia type 1 (MEN1) gene was sequenced, thus enabling diagnosis and early optimal treatment. Patients carrying the MEN1 gene present endocrine but also non-endocrine tumors. Parathyroid, pancreatic and pituitary impairment are the three main types of endocrine involvement. The present article details therapeutic management of hyperparathyroidism, neuroendocrine pancreatic tumors and pituitary adenomas in patients carrying the MEN1 gene. Significant therapeutic progress has in fact been made in the last few years. As concerns the parathyroid glands, screening of family members and regular monitoring of affected subjects now raise the question of early management of parathyroid lesions and optimal timing of parathyroid surgery. As concerns the duodenum-pancreas, proton-pump inhibitors are able to control gastrin-secreting syndrome, reducing mortality in MEN1 patients. Mortality in MEN1 patients is no longer mainly secondary to uncontrolled hormonal secretion but to metastatic (mainly pancreatic) disease progression. Tumor risk requires regular monitoring of morphological assessment, leading to iterative pancreatic surgery in a large number of patients. Finally, pituitary adenomas in MEN1 patients are traditionally described as aggressive, invasive and resistant to medical treatment. However, regular pituitary screening showed them to be in fact infra-centimetric and non-secreting in the majority of patients. Consequently, it is necessary to regularly monitor MEN1 patients, with regular clinical, biological and morphological work-up. Several studies showed that this regular monitoring impairs quality of life. Building a relationship of trust between patients and care provider is therefore essential. It enables the patient to be referred for psychological or psychiatric care in difficult times, providing long-term support and preventing any breakdown in continuity of care.

Clinical aspects of multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) is a rare syndrome characterized by the co-occurrence of primary hyperparathyroidism, duodenopancreatic neuroendocrine tumours (NETs) and/or pituitary adenomas. MEN1 can predispose patients to other endocrine and non-endocrine tumours, such as cutaneous tumours, central nervous system tumours and breast cancer. Endocrine tumours in patients with MEN1 differ from sporadic tumours in that they have a younger age at onset, present as multiple tumours in the same organ and have a different clinical course. Therefore, patients with overt MEN1 and those who carry a MEN1 mutation should be offered tailored biochemical and imaging screening to detect tumours and evaluate their progression over time. Fortunately, over the past 10 years, knowledge about the clinical phenotype of these tumours has markedly progressed, thanks to the implementation of national registries, particularly in France and the Netherlands. This Review provides an update on the clinical management of MEN1-related tumours. Epidemiology, the clinical picture, diagnostic work-up and the main lines of treatment for MEN1-related tumours are summarized. Controversial therapeutic aspects and issues that still need to be addressed are also discussed. Moreover, special attention is given to MEN1 manifestations in children and adolescents.

Optimal extent of initial parathyroid resection in patients with multiple endocrine neoplasia syndrome type 1: A meta-analysis

BACKGROUND

Hyperparathyroidism is an almost universal feature of multiple endocrine neoplasia type 1 syndrome. We present a systematic review and meta-analysis of the postoperative outcomes of patients undergoing initial operative treatment of primary hyperparathyroidism complicating multiple endocrine neoplasia 1.

METHODS

A comprehensive literature search was performed with a priori defined exclusion criteria for studies comparing total parathyroidectomy, subtotal parathyroidectomy, and less than subtotal parathyroidectomy.

RESULTS

Twenty-one studies incorporating 1,131 patients (272 undergoing total parathyroidectomy, 510 subtotal parathyroidectomy, and 349 less than subtotal parathyroidectomy) were identified. Pooled results revealed increased risk for long-term hypoparathyroidism in total parathyroidectomy patients (relative risk 1.61; 95% confidence interval, 1.12-2.31; P = .009) versus those undergoing subtotal parathyroidectomy. In the less than subtotal parathyroidectomy or subtotal parathyroidectomy comparison group, a greater risk for recurrence of hyperparathyroidism (relative risk 1.37; 95% confidence interval, 1.05-1.79; P = .02), persistence of hyperparathyroidism (relative risk 2.26; 95% confidence interval, 1.49-3.41; P = .0001), and reoperation for hyperparathyroidism (relative risk 2.48; 95% confidence interval, 1.65-3.73; P < .0001) was noted for less than subtotal parathyroidectomy patients, albeit with lesser risk for long-term for hypoparathyroidism (relative risk 0.47; 95% confidence interval, 0.29-0.75; P = .002).

CONCLUSION

Subtotal parathyroidectomy compares favorably to total parathyroidectomy, exhibiting similar recurrence and persistence rates with a decreased propensity for long-term postoperative hypoparathyroidism. The benefit of the decreased risk of hypoparathyroidism in less than subtotal parathyroidectomy is negated by the increase in the risk for recurrence, persistence, and reoperation. Future studies evaluating the performance of less than subtotal parathyroidectomy in specific multiple endocrine neoplasia 1 phenotypes should be pursued in an effort to delineate a patient-tailored, operative approach that optimizes long-term outcomes.

Bone Metabolism and Vitamin D Implication in Gastroenteropancreatic Neuroendocrine Tumors

Patients affected by gastroenteropancreatic–neuroendocrine tumors (GEP–NETs) have an increased risk of developing osteopenia and osteoporosis, as several factors impact on bone metabolism in these patients. In fact, besides the direct effect of bone metastasis, bone health can be affected by hormone hypersecretion (including serotonin, cortisol, and parathyroid hormone-related protein), specific microRNAs, nutritional status (which in turn could be affected by medical and surgical treatments), and vitamin D deficiency. In patients with multiple endocrine neoplasia type 1 (MEN1), a hereditary syndrome associated with NET occurrence, bone damage may carry other consequences. Osteoporosis may negatively impact on the quality of life of these patients and can increment the cost of medical care since these patients usually live with their disease for a long time. However, recommendations suggesting screening to assess bone health in GEP–NET patients are missing. The aim of this review is to critically analyze evidence on the mechanisms that could have a potential impact on bone health in patients affected by GEP–NET, focusing on vitamin D and its role in GEP–NET, as well as on factors associated with MEN1 that could have an impact on bone homeostasis.

Recent advances in the understanding and management of primary hyperparathyroidism

Primary hyperparathyroidism is a hormonal disorder whose prevalence is approximately 1–2% in the United States of America. The disease has become more recognizable to clinicians in an earlier phase and, at present, patients can be diagnosed with “classic”, “normocalcemic”, “normohormonal”, or “mild, asymptomatic” primary hyperparathyroidism. Surgery, with a focused parathyroidectomy when possible, or a four-gland exploration, is the only way to cure the disease. Cure is determined by use of intra-operative parathyroid hormone monitoring with long-term cure rates ranging from 90–95%. Newer adjuncts to surgery include CT or PET imaging and near-infrared immunofluorescence. This article highlights updates in parathyroid disease and advances in parathyroid surgery; it does not provide a comprehensive summary of the disease process or a review of surgical indications, which can be found in the AAES guidelines or NIH Symposium on primary hyperparathyroidism.