Primary hyperparathyroidism: 11-year experience in a single institute in Thailand

Changing trends in clinical presentation of primary hyperparathyroidism across countries over time

Primary hyperparathyroidism (PHPT), the third most common endocrine disorder, was so eloquently described first by Fuller Albright as a polymorphic condition in his classic paper and monograph as early as 1934. Over the decades, the clinical presentation of PHPT in developed countries has shifted significantly from a disease primarily affecting the bones and kidneys to an asymptomatic condition often discovered incidentally. In developing countries, the high prevalence of vitamin D deficiency is one of the main factors influencing the clinical presentation of PHPT. In Europe and North America, PHPT is predominantly asymptomatic. In South America, China, and Eastern parts of Europe, such as Turkey, Bulgaria, and Russia, there is an ongoing transition from symptomatic to asymptomatic cases. Asia shows variability: symptomatic cases dominate in the Indian subcontinent, Middle East, and Southeast Asia, while transitional patterns with predominant asymptomatic cases have now been reported in China, and Japan reports mostly asymptomatic cases. Factors influencing these changes include advancements in diagnostic technologies, detection of incidental parathyroid adenomas during thyroid ultrasonography, regional differences in vitamin D deficiency, dietary habits, and genetic polymorphisms in vitamin D and calcium-sensing receptors. A higher prevalence of nephrolithiasis in certain climates contributes to regional variations. This review examines the dynamic nature of PHPT's clinical presentation, shaped by geographic, genetic, and environmental influences. Also, this review highlights the importance of addressing global disparities in an attempt to optimize patient outcomes.

Clinico-Pathological Study of Symptomatic Hyperparathyroidism: Is it a Different Phenotype Expression of Hyperparathyroidism?

Despite the popularity of auto analyzers in urban areas of the country the incidence of asymptomatic hyperparathyroidism has not markedly increased and symptomatic diseases are regularly seen in all major institutions. The present single-institution analysis of proven hyperparathyroidism in the last 16 years was aimed at comparing the demographic, clinical, and pathological characteristics of symptomatic and asymptomatic primary hyperparathyroidism and comparing those with the asymptomatic diseases seen in developed countries. A retrospective chart review of 332 patients was done and 29 (8.7%) were asymptomatic. The asymptomatic patients were older than the symptomatic patients and showed significantly low disease severity features like serum PTH and tumor weight. However, 48.3% of the subset had serum PTH levels 3 times above the upper value of the reference level and the tumor weight was considerably high compared to that of the counterparts in developed countries. The demographic, clinical, and glandular pathology features of asymptomatic primary hyperparathyroid patients differ from those of similar patients in developed countries.

Outcome of Primary Hyperparathyroidism: Retrospective Tertiary Center Experience From Basrah, Iraq

BACKGROUND

Primary hyperparathyroidism is regarded as a common endocrine disorder that is biochemically identified and could be symptomatic or asymptomatic. A detailed history and a thorough evaluation with regular follow-ups are required until a definite diagnosis is made. The study aims to evaluate the characteristics of patients and the performance of a tertiary endocrine center in managing the disease in Basrah, Iraq.

MATERIAL AND METHODS

A retrospective study was conducted at the Faiha Specialized Diabetes, Endocrine, and Metabolism Center in Basrah, southern Iraq, on 106 patients diagnosed with primary hyperparathyroidism between 2012 and 2023. The patients' general characteristics were assessed, and those who underwent parathyroidectomy were evaluated post-surgery, and the cure rate was determined.

RESULTS

The mean age of presentation was 47.5 ± 14.6 years, with a median of 50 years. The highest occurrence is in the sixth decade. Females comprised 79 (75%) of the patients, and the female-to-male ratio was 3:1. Symptomatic patients were 84 (90%), 30 (70%) of the patients had nephrolithiasis, and 52 (68%) had osteoporosis. The cure rate was 15 (83%).

CONCLUSION

In our single-center study, the frequency of primary hyperparathyroidism has increased with time. The disease's highest occurrence was seen in the sixth decade. Females were substantially higher than males. Most patients were symptomatic. The cure rate was 83%.

Brown tumors: Retrospective analysis of 26 cases

INTRODUCTION

Brown tumors are reactive osteolytic lesions caused by hyperparathyroidism. These rare lesions are non-neoplastic processes that result from bone resorption. The purpose of this study was to retrospectively review a 34-year experience with brown tumors in our institution.

MATERIALS AND METHODS

We retrospectively analyzed the records of 26 consecutive patients with brown tumor who were treated in our institution between May 1988 and October 2020, with a mean follow-up of 36,1 months.

RESULTS

17 male (65,4%) and 9 female (34,6%) patients with a mean age of 41,6 were included in the study. Localized bone pain was present in 13 cases (50,0%) as the first presenting symptom. 3 patients (11,5%) presented with diffuse bone pain. 7 patients (26,9%) were diagnosed with brown tumor while being investigated for pathological fractures. The other 3 patients (11,5%) were diagnosed while being evaluated for hypercalcemia symptoms. 7 patients (26,9%) had solitary lesions, while 19 patients (73,1%) had multiple lesions. Pelvis, femur, ribs, tibia, proximal humerus and mandible were the most common sites of localization. 23 patients (88,5%) were diagnosed with primary hyperparathyroidism, while the other 3 patients (11,5%) had secondary hyperparathyroidism. A total of the 65 lesions, 23 (35.4%) underwent orthopedic surgery, and 42 (64.6%) were followed up conservatively after parathyroidectomy. Orthopedic surgery was performed in 21 of 26 patients, the other 5 cases were followed up conservatively. Intralesional curettage was performed in 19 cases (82,6%). The resulting cavity was filled with bone cement in 11 cases (47,8%). Bone grafting was applied in 8 cases (34,8%). No recurrence was observed in any of the patients.

CONCLUSION

The diagnosis of brown tumor begins with clinical suspicion. Endocrinology and general surgery consultation is important before surgery. Treatment of brown tumors requires a multidisciplinary approach.

Primary hyperparathyroidism

Primary hyperparathyroidism (PHPT), the most common cause of hypercalcemia, is most often identified in postmenopausal women with hypercalcemia and parathyroid hormone (PTH) levels that are either frankly elevated or inappropriately normal. The clinical presentation of PHPT includes three phenotypes: target organ involvement of the renal and skeletal systems; mild asymptomatic hypercalcemia; and more recently, high PTH levels in the context of persistently normal albumin-corrected and ionized serum calcium values. The factors that determine which of these three clinical presentations is more likely to predominate in a given country include the extent to which biochemical screening is employed, the prevalence of vitamin D deficiency, and whether a medical center or practitioner tends to routinely measure PTH levels in the evaluation of low bone density or frank osteoporosis. When biochemical screening is common, asymptomatic primary hyperparathyroidism is the most likely form of the disease. In countries where vitamin D deficiency is prevalent and biochemical screening is not a feature of the health care system, symptomatic disease with skeletal abnormalities is likely to predominate. Finally, when PTH levels are part of the evaluation for low bone mass, the normocalcemic variant is seen. Guidelines for surgical removal of hyperfunctioning parathyroid tissue apply to all three clinical forms of the disease. If guidelines for surgery are not met, parathyroidectomy can also be an appropriate option if there are no medical contraindications to surgery. In settings where either the serum calcium or bone mineral density is of concern, and surgery is not an option, pharmacological approaches are available and effective. Referencing in this article the most current published articles, we review the different presentations of PHPT, with particular emphasis on recent advances in our understanding of target organ involvement and management.

Quality of Life in Primary Hyperparathyroidism

Quality of life is impaired in primary hyperparathyroidism (PHPT), regardless of the severity of the disease. Clinical studies have employed different instruments, including standardized and disease-specific questionnaires, and including patients with different phenotypes of PHPT. Neuropsychiatric symptoms and decline in cognitive status are common in PHPT. Patients may complain of these issues or they can be ascertained by questionnaires; they include depression, anxiety, impaired vitality, social and emotional functions, sleep disturbances, and altered mental function. Randomized controlled trials on the effects of surgical versus non-surgical treatments have collectively shown improvement in quality of life after parathyroidectomy, but results have been heterogeneous.

One hundred and one consecutive transoral endoscopic parathyroidectomies via the vestibular approach for PHPTH: a worldwide multi-institutional experience

IMPORTANCE

The transoral vestibular approach for thyroid and parathyroid surgery is being adopted rapidly world-wide. Currently there is a paucity of information on this approach for primary hyperparathyroidism (PHPTH). If this approach is safe and efficacious it would provide patients a completely scarless option for parathyroidectomy.

OBJECTIVE

To determine whether parathyroidectomy via the transoral vestibular approach can be successfully done in a safe and efficient manner.

DESIGN

Consecutive case series of 101 transoral parathyroidectomies performed over a two-year period.

SETTING

Multi-institutional, academic, high-volume transoral thyroidectomy centers from the USA, Israel, and Thailand.

PARTICIPANTS

A consecutive series of adult patients with a biochemical diagnosis of classic PHPTH and who met criteria for parathyroidectomy based on established international consensus for surgery for PHPTH. All patients also had well-localized single adenomas on at least two preoperative imaging studies.

INTERVENTION

Transoral endoscopic parathyroidectomy vestibular approach.

MAIN OUTCOMES AND MEASURES

Surgical success rate defined by immediate intra or post-operative return to normal PTH values. Surgical complications including recurrent laryngeal nerve injury, permanent hypoparathyroidism, and infection.

RESULTS

Of the 101 consecutive transoral parathyroidectomy patients 84% were female with an average age of 54.23 ± 11.0 years and an average BMI of 27.35 ± 6.19. Ninety-nine out of the 101 patients had immediate return to normal PTH after resection for a surgical success rate of 98%. There were no permanent recurrent laryngeal nerve injuries, one temporary nerve palsy, and no permanent hypoparathyroidism. The median operative time dropped from 130.5 min (IQR 86) to 66.5 min (IQR 56) between the first- and second-half of cases.

CONCLUSION AND RELEVANCE

Transoral endoscopic parathyroidectomy via the vestibular approach is a scarless method of removing parathyroids that is clinically feasible, safe, and efficacious and is a reasonable option for focused minimally invasive parathyroidectomy that can be offered to select patients with PHPTH.

Acute cardiac damage and acute kidney injury associated with hypercalcemia crisis in hyperparathyroidism: a case report

Hyperparathyroidism-induced hypercalcemic crisis is a rare presentation of primary hyperparathyroidism. Primary hyperparathyroidism is caused by uncontrolled and immoderate secretion of parathyroid hormone. The most common presentation in primary hyperparathyroidism is renal stones, soft tissue calcification, cystic bone disease, and even hypercalcemic crisis. We report a patient who presented with multiple organ dysfunction syndrome due to extreme hypercalcemia (serum calcium concentration, 4.79 mmol/L [2.15–2.25 mmol/L]) resulting from primary hyperparathyroidism (serum parathyroid hormone concentration, 2215 pg/mL). The complications in this patient were complete cardiac damage and acute kidney injury. On the basis of the hypercalcemic crisis, the patient subsequently underwent surgical resection of parathyroid adenoma. Two days after surgery, her serum calcium and parathyroid hormone concentrations were normal. The patient had a good recovery after a series of other relevant therapies. In conclusion, surgery should be taken into consideration for hyperparathyroidism.

Which biochemical and clinical parameters correlate with parathyroid adenoma weight? Turkish-Bulgarian endocrine and breast surgery study group, hyperparathyroidism registry study

BACKGROUND

Primary hyperparathyroidism (pHPT) caused by a single benign parathyroid adenoma is a common endocrine disorder that is affected by regional differences. Living in different geographical regions reveals differences in the laboratory results and pathological findings, but studies on this subject are not sufficient. The article focuses on biochemical and pathological effects of geographical differences in parathyroid adenoma. In addition, the present study seeks to elaborate on treatment methods and effectiveness of screening in geographical area of Bulgaria and Turkey.

METHOD

In this prospective study, 159 patients were included from 16 centres. Demographic characteristics, symptoms, biochemical markers and pathologic characteristics were analysed and compared between 8 different regions.

RESULTS

Patients from Turkish Black Sea had the highest median serum calcium (Ca) level, whereas patients from Eastern Turkey had the lowest median serum phosphorus (P) level. On the other hand, there was no significant difference between Ca, parathormone (PTH) and P levels according to regions. Patients from Eastern Turkey had the highest adenoma weight, while patients from Bulgaria had the lowest adenoma weight. The weight of adenoma showed statistically significant differences between regions (p < 0.001). There was a correlation between adenoma weight and serum PTH level (p = 0.05) and Ca level (p = 0.035).

CONCLUSION

This study has provided a deeper insight into the effect of the regional differences upon clinicopathological changing and biochemical values of pHTP patients with adenoma. Awareness of regional differences will assist in biochemical screening and treatment of this patient group.

Osteitis Fibrosa Cystica and pathological fractures-the classic but neglected skeletal manifestation of primary hyperparathyroidism: a case report

BACKGROUND

Osteitis fibrosa cystica is the classic manifestation of primary hyperparathyroidism (PHPT), occurs after prolonged exposure of bone to high serum parathyroid hormone (PTH) level. It has become increasingly rare due to early detection of PHPT.

CASE PRESENTATION

A 37-year-old woman was referred to our institution for fixation of multiple fractures of upper and lower extremities that had been reoccurring in the past 5 years. Her medical history showed right-shoulder, left-elbow, and right-femur fractures after a fall 5 years previously. One month ago, she sustained fractures of the right distal humerus, left tibia, and left femur without history of trauma. Upon arrival to our hospital, a thorough review of her plain radiographs demonstrated brown tumors at multiple sites, along with a salt-and-pepper appearance of the skull and a rugger-jersey spine, compatible with osteitis fibrosa cystica. Patient was diagnosed with PHPT, confirmed by high-corrected serum calcium (13.6 [8.6-10.0] mg/dl), low serum phosphate (2.2 [2.5-4.5] mg/dL), high serum alkaline phosphatase (1482 [35-105] U/L), and significantly elevated parathyroid hormone (PTH 3850 [15-65] pg/mL). A histologically confirmed, 2.5-cm parathyroid adenoma was removed by parathyroidectomy. Ten days later, closed reduction and internal fixation of the left proximal femoral shaft was performed. Pain and ambulation were significantly improved 6 months postoperatively. At the 1.5-year follow-up, fracture unions and complete mineralization of brown tumors were noted; the patient could ambulate with neither pain nor an assistive device.

CONCLUSIONS

PHPT has become more asymptomatic in countries where routine calcium screening is performed. Nevertheless, the classic skeletal involvement, osteitis fibrosa cystica, should not be overlooked, particularly in young patients who present with a low-energy fracture.

Progressive rise in the prevalence of asymptomatic primary hyperparathyroidism in India: Data from PHPT registry

INTRODUCTION

Primary hyperparathyroidism (PHPT), a third common endocrine disorder, varies from asymptomatic disease, mostly seen in the West where routine biochemical screening is practiced, to the classical symptomatic disease mostly seen in the Eastern countries. We aimed to compare the demographic, clinical, biochemical measurements in patients with asymptomatic and symptomatic PHPT from the Indian PHPT registry.

MATERIAL AND METHODS

Data of PHPT patients from the last 25 years (1995-2019) were analyzed for demographic, clinical presentation and biochemical measurements, and compared these characteristics between asymptomatic and symptomatic PHPT patients.

RESULTS

Of the 554 patients, 54 (10%) patients had asymptomatic PHPT. There was a sharp rise in the proportion of asymptomatic PHPT patients of 3% in the first decade to 13% in the second decade of the century (p = 0.003). Patients with asymptomatic PHPT were significantly older (50 vs. 42 years; p < 0.0001) and had higher mean body mass index (27.8 vs. 23.5 kg/m²; p < 0.0001) compared to the symptomatic PHPT group. In addition, asymptomatic PHPT patients had significantly lower median plasma iPTH (180 vs. 370 pg/mL; p < 0.0001), serum alkaline phosphatase (119 vs. 172 IU/L; p < 0.0001), and parathyroid adenoma weight (1.0 vs. 2.62 g; p = 0.006) compared to the symptomatic PHPT group.

CONCLUSION

Although symptomatic PHPT is still most prevalent (> 90%) in India with higher indices of the disease and tumor weights, there is a progressive rise in the prevalence of asymptomatic PHPT patients in the last decade. Improvements in calcium and vitamin D nutrition might account for this change as in the Western series.

Clinical Characteristics of Primary Hyperparathyroidism: 15-Year Experience of 457 Patients in a Single Center in China

Objective

Primary hyperparathyroidism (PHPT) is a common endocrine disorder of calcium metabolism. However, data concerning a large cohort of PHPT patients in the Chinese population are scarce. Thus, the objective of this study was to determine the general clinical signatures of 457 Chinese PHPT patients and explore the clinical characteristic differences between benign and malignant PHPT.

Methods

A single-center retrospective study was designed. Medical records between preoperation and postoperative follow-up, were assessed and statistical analysis of the clinical data was performed.

Results

Patients with PHPT aged 12-87 years, with a mean onset age of 56.16 ± 14.60 years, were included. Most patients (68.7%) in our center had symptomatic patterns described as bone pain (74.8%), urolithiasis (25.5%), fatigue (17.5%), and pathological fracture (13.1%), but an increasing tendency has been established in the proportion of patients with asymptomatic forms. Correlation analysis revealed that patients with higher serum levels of parathyroid hormone (PTH) and calcium presented higher serum levels of bone turnover markers (BTMs) and lower 25-hydroxy-vitamin D (25OHD) values (P<0.001). Gains in bone mineral density (BMD) at L1-4, the femoral neck and the total hip were observed 1-2 years after parathyroidectomy (9.6, 5.9, and 6.8%). Parathyroid carcinoma patients presented prominently higher serum PTH and calcium levels and BTMs and lower BMD at femoral neck and total hip than benign PHPT patients (P<0.05), while no significant differences in age, sex, and serum 25OHD concentration were observed between benign and malignant PHPT patients.

Conclusions

PHPT should be paid attention to in the patients with bone pain. While, BMD and BTMs can differentiate parathyroid carcinoma from parathyroid adenoma and hyperplasia to some extent. In addition, anti-osteoporosis drugs could be used when necessary to avoid hip fractures in patients with parathyroid carcinoma.

Monocentric experience of primary hyperparathyroidism surgery in Algeria

Introduction

Primary hyperparathyroidism (PHPT) remains a relatively underdiagnosed disease in developing countries. The aim of this study was to assess the demographic, pathological, biochemical, and surgical characteristics of patients with primary hyperparathyroidism in a university hospital department of otolaryngology in eastern Algeria.

Materials and method

We performed a retrospective analysis of the records of 62 patients operated in our department for primary hyperparathyroidism between January 2002 and December 2013.

Results

The mean age was 47.7 ± 15 years with a female preponderance (88.7%). The mode of discovery was during a biological assessment for bone syndrome in 42% of cases. The mean calcemia was 2.92 ± 0.6 mmol/L, and the intact serum parathyroid hormone was 867.78 ± 954.50 pmol/L. A total of 54.8% of patients had bilateral neck exploration, and 45.2% had minimally invasive open parathyroidectomy. Postoperative complications were dominated by severe hypocalcemia and hungry bone syndrome.

Conclusion

The diagnosis of primary hyperparathyroidism in our country is late, and management is often performed after the appearance of bone and renal complications.

•

Primary hyperparathyroidism is an underdiagnosed disease in developing countries.

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The diagnosis is made after the appearance of bone and renal complications.

•

Bone manifestations are the most common presenting symptoms.

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Biochemical profile is dominated by hypercalcemia and elevated serum parathyroid hormone levels.

•

Average adenoma weight is very high, correlating with severe hyperparathyroidism.

•

Hypocalcemia and hungry bone syndrome are the most common postoperative complications.

Primary hyperparathyroidism in developing world: a systematic review on the changing clinical profile of the disease

While the developed world is focusing on laying guidelines for selecting out cases of Asymptomatic primary hyperparathyroidism (PHPT) for surgical intervention and promoting minimal access surgery, the developing world is observing a change in disease spectrum from advanced symptomatic to lesser degree of symptomatic disease and not many with associated Vitamin D deficiency. Few studies from the developing countries of the world have focused on the changing clinical spectrum of PHPT. Objective of this study is to review the changing profile of PHPT in developing world. A systematic literature search was done in December 2017 focussing on publications from the developing world. All studies pertaining to the epidemiology of PHPT published after 1st January 2000 and published in English language were included for analysis. Most of the studies published from developing countries report a predominance of symptomatic disease (79.6% of all included patients) with musculoskeletal disease present in the majority of patients (52.9%). The combined mean serum total calcium (11.9 ± 1.4 mg/dL), serum PTH (668.6 ± 539 pg/mL), serum alkaline phoshpatase (619 ± 826.9 IU/L) and weight of excised parathyroid glands (4.4 ± 3.8 grams) are much higher than those reported from the western studies. Despite this, we found that there is a distinct trend towards a milder form of disease presentation and biochemical profile noticeable in more recent times. Although there is a striking difference in all aspects of PHPT disease epidemiology, clinical presentation and biochemical profile of developing and developed countries, there is a distinct trend towards a milder form of disease presentation and biochemical profile in more recent times.

Clinical Characterization of Post-parathyroidectomy Patients with Primary Hyperparathyroidism and the Concordance of Preoperative Localization Imaging with Histopathology at a Tertiary Hospital in Manila, Philippines

Background

Philippine studies on primary hyperparathyroidism (PHPT) and preoperative localization are scarce, making improvements on detection and recognition particularly difficult.

Objective

Describe the clinical profile of post-parathyroidectomy PHPT patients at The Medical City (TMC) and assess localization rates and concordance of neck ultrasound (UTZ) and 99mTc-sestamibi scan (MIBI) with surgical histopathologic findings.

Methodology

Retrospective chart review of PHPT Filipino patients who underwent parathyroidectomy at The Medical City from January 2004 to August 2018. Clinical profile and presentations were described and compared with international data. Imaging results were compared with surgical histopathology findings and the level of agreement was determined.

Results

Thirty-five patients were analyzed with female predominance (63%) and an average age of 53 years. Our population had more overt manifestations including skeletal abnormalities (51%), renal calculi (49%) and musculoskeletal symptoms (43%) prior to surgery compared to western countries, where symptoms were noted in less than 20%. MIBI had higher rates of detection than UTZ (80% versus 58%) but had similar localization rates (96.4% versus 94%). When performed together, given a positive result from either test, a much higher yield (93.8%) was observed. The level of agreement between MIBI and surgery was 72.5% (κ=0.54) while UTZ and surgery was 54.1% (κ=0.38).

Conclusion

Our Filipino subjects had predominantly overt symptomatic hyperparathyroidism upon diagnosis prior to surgery as opposed to more asymptomatic surgical patients in western countries. Combining UTZ and MIBI is a more successful preoperative localization approach in our setting than performing either imaging alone, especially in patients with nodular goiter.

Surgical Management of Primary Hyperparathyroidism in the Era of Focused Parathyroidectomy: A Study in Tertiary Referral Centre of North India

BACKGROUND

Despite the benefits of focused parathyroidectomy (FPTx), few studies have questioned its durability with lower long-term cure rates than bilateral or conventional parathyroidectomy (CPTx). The objective of this study is to bring out the information on the type of surgical management versus cure rate, recurrence, and role of intra-operative parathyroid hormone (IOPTH) level monitoring of PHPT patients.

MATERIAL AND METHODS

This was a retrospective study of all PHPT patients treated at our center based on operative approach (CPTx vs FPTx) or use of IOPTH. Treatment failure was divided into persistent or recurrent disease, based on documentation of hypercalcemia in combination with an inappropriate PTH within 6 months or more of surgery, respectively.

RESULTS

Overall, 50.78% patients underwent CPTx and 49.32% FPTx. 29 FPTx were converted to CPTx. Intention to treat analysis between CPTx and FPTx showed that the persistence rate was not statistically different at 2.54% and 4%, respectively (P = 0.98). Furthermore, when the persistence rate was scrutinized by a treatment received (TR) instead of ITT analysis, the persistence rate was higher for the patients who underwent TR-CPTX than for the patients subjected to TR-FPTX (3.22% vs 1.08%) but not significant statistically. We further analyzed the outcome of FPTx with IOPTH (n = 213) and FPTx without IOPTH (n = 28). The outcome did not differ between two groups statistically.

CONCLUSION

FPTx yields a similar success rate as compared to CPTx even in symptomatic PHPT patients and can be performed safely even without intra-opeartive adjunct IOPTH in selected patients.

Primary hyperparathyroidism

Primary hyperparathyroidism (PHPT), the most common cause of hypercalcemia, is most often identified in postmenopausal women with hypercalcemia and parathyroid hormone (PTH) levels that are either frankly elevated or inappropriately normal. The clinical presentation of PHPT includes three phenotypes: target organ involvement of the renal and skeletal systems; mild asymptomatic hypercalcemia; and more recently, high PTH levels in the context of persistently normal albumin-corrected and ionized serum calcium values. The factors that determine which of these three clinical presentations is more likely to predominate in a given country include the extent to which biochemical screening is employed, the prevalence of vitamin D deficiency, and whether a medical center or practitioner tends to routinely measure PTH levels in the evaluation of low bone density or frank osteoporosis. When biochemical screening is common, asymptomatic primary hyperparathyroidism is the most likely form of the disease. In countries where vitamin D deficiency is prevalent and biochemical screening is not a feature of the health care system, symptomatic disease with skeletal abnormalities is likely to predominate. Finally, when PTH levels are part of the evaluation for low bone mass, the normocalcemic variant is seen. Guidelines for surgical removal of hyperfunctioning parathyroid tissue apply to all three clinical forms of the disease. If guidelines for surgery are not met, parathyroidectomy can also be an appropriate option if there are no medical contraindications to surgery. In settings where either the serum calcium or bone mineral density is of concern, and surgery is not an option, pharmacological approaches are available and effective. Referencing in this article the most current published articles, we review the different presentations of PHPT, with particular emphasis on recent advances in our understanding of target organ involvement and management.

Hyperparathyroidism

Primary hyperparathyroidism is a common endocrine disorder of calcium metabolism characterised by hypercalcaemia and elevated or inappropriately normal concentrations of parathyroid hormone. Almost always, primary hyperparathyroidism is due to a benign overgrowth of parathyroid tissue either as a single gland (80% of cases) or as a multiple gland disorder (15-20% of cases). Primary hyperparathyroidism is generally discovered when asymptomatic but the disease always has the potential to become symptomatic, resulting in bone loss and kidney stones. In countries where biochemical screening tests are not common, symptomatic primary hyperparathyroidism tends to predominate. Another variant of primary hyperparathyroidism has been described in which the serum calcium concentration is within normal range but parathyroid hormone is elevated in the absence of any obvious cause. Primary hyperparathyroidism can be cured by removal of the parathyroid gland or glands but identification of patients who are best advised to have surgery requires consideration of the guidelines that are regularly updated. Recommendations for patients who do not undergo parathyroid surgery include monitoring of serum calcium concentrations and bone density.

Primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a common disorder in which parathyroid hormone (PTH) is excessively secreted from one or more of the four parathyroid glands. A single benign parathyroid adenoma is the cause in most people. However, multiglandular disease is not rare and is typically seen in familial PHPT syndromes. The genetics of PHPT is usually monoclonal when a single gland is involved and polyclonal when multiglandular disease is present. The genes that have been implicated in PHPT include proto-oncogenes and tumour-suppressor genes. Hypercalcaemia is the biochemical hallmark of PHPT. Usually, the concentration of PTH is frankly increased but can remain within the normal range, which is abnormal in the setting of hypercalcaemia. Normocalcaemic PHPT, a variant in which the serum calcium level is persistently normal but PTH levels are increased in the absence of an obvious inciting stimulus, is now recognized. The clinical presentation of PHPT varies from asymptomatic disease (seen in countries where biochemical screening is routine) to classic symptomatic disease in which renal and/or skeletal complications are observed. Management guidelines have recently been revised to help the clinician to decide on the merits of a parathyroidectomy or a non-surgical course. This Primer covers these areas with particular attention to the epidemiology, clinical presentations, genetics, evaluation and guidelines for the management of PHPT.

Current issues in the presentation of asymptomatic primary hyperparathyroidism: proceedings of the Fourth International Workshop

OBJECTIVE

This report summarizes data on traditional and nontraditional manifestations of primary hyperparathyroidism (PHPT) that have been published since the last International Workshop on PHPT.

PARTICIPANTS

This subgroup was constituted by the Steering Committee to address key questions related to the presentation of PHPT. Consensus was established at a closed meeting of the Expert Panel that followed.

EVIDENCE

Data from the 5-year period between 2008 and 2013 were presented and discussed to determine whether they support changes in recommendations for surgery or nonsurgical follow-up.

CONSENSUS PROCESS

Questions were developed by the International Task Force on PHPT. A comprehensive literature search for relevant studies was undertaken. After extensive review and discussion, the subgroup came to agreement on what changes in the recommendations for surgery or nonsurgical follow-up of asymptomatic PHPT should be made to the Expert Panel.

CONCLUSIONS

1) There are limited new data available on the natural history of asymptomatic PHPT. Although recognition of normocalcemic PHPT (normal serum calcium with elevated PTH concentrations; no secondary cause for hyperparathyroidism) is increasing, data on the clinical presentation and natural history of this phenotype are limited. 2) Although there are geographic differences in the predominant phenotypes of PHPT (symptomatic, asymptomatic, normocalcemic), they do not justify geography-specific management guidelines. 3) Recent data using newer, higher resolution imaging and analytic methods have revealed that in asymptomatic PHPT, both trabecular bone and cortical bone are affected. 4) Clinically silent nephrolithiasis and nephrocalcinosis can be detected by renal imaging and should be listed as a new criterion for surgery. 5) Current data do not support a cardiovascular evaluation or surgery for the purpose of improving cardiovascular markers, anatomical or functional abnormalities. 6) Some patients with mild PHPT have neuropsychological complaints and cognitive abnormalities, and some of these patients may benefit from surgical intervention. However, it is not possible at this time to predict which patients with neuropsychological complaints or cognitive issues will improve after successful parathyroid surgery.