Sporadic multiple parathyroid gland disease--a consensus report of the European Society of Endocrine Surgeons (ESES)

Parathyroidectomy for solitary parathyroid adenoma via trans-areola single site endoscopic approach: Results of a case-match study

BACKGROUND

This study aimed to establish the standardized procedure of trans-areola single site endoscopic parathyroidectomy (TASSEP), and to compare the performance of TASSEP with that of conventional open parathyroidectomy (COP).

METHODS

This study enrolled 40 patients with primary hyperparathyroidism (PHPT) who underwent TASSEP, and included 40 of 176 PHPT patients who underwent COP based on propensity score matching. The retrospective analysis was conducted based on prospectively collected data. Perioperative outcomes, including surgical profile, surgical burden and cosmetic results and follow-up were reported. The learning curve was described using a cumulative sum (CUSUM) analysis.

RESULTS

40 TASSEPs were completed successfully without conversions or severe complications. There was no statistically significant difference in operation time between TASSEP and COP groups (80.83 ± 11.95 vs. 76.95 ± 7.30 min, p = 0.084). Experience of 17 cases was necessitated to reach the learning curve of TASSEP. Postoperative pain score and traumatic index (C-reactive protein and erythrocyte sedimentation rate) in TASSEP were apparently lower than those in COP group (p < 0.05). During the proliferation and stabilization phases, TASSEP was associated with significantly better incision recovery and cosmetic scores. Postoperative serum calcium and PTH levels throughout the follow-up period indicated satisfactory surgical qualities in both groups.

CONCLUSION

Based on precise preoperative localization and intraoperative planning facilitated by three-dimensional (3D) virtual modeling, TASSEP can be feasibly performed on selected patients with satisfactory success rates and low complication rates, providing preferable cosmetic results and alleviating the surgical burden to a certain extent.

Primary hyperparathyroidism: predictors of sporadic multi-gland disease

In this review, we discuss the definition, prevalence, and etiology of sporadic multiglandular disease (MGD), with an emphasis on its preoperative and intraoperative predictors. Primary hyperparathyroidism (PHPT) is the third-most common endocrine disorder, and multiglandular parathyroid disease (MGD) is a cause of PHPT. Hereditary MGD can be definitively diagnosed with detailed family history and genetic testing, whereas sporadic MGD presents a greater challenge in clinical practice, and parathyroidectomy for MGD is associated with a higher risk of surgical failure than single gland disease (SGD). Therefore, it is crucial to be able to predict the presence of sporadic MGD in a timely manner, either preoperatively or intraoperatively. Various predictive methods cannot accurately identify all cases of sporadic MGD, but they can greatly optimize the management of MGD diagnosis and treatment and optimize the cure rate. Future research will urge us to investigate more integrative predictive models as well as increase our understanding of MGD pathogenesis.

Molecular Genetic Aspects of Sporadic Multiglandular Primary Hyperparathyroidism

Multiglandular primary hyperparathyroidism (MGD) represents a rare form of primary hyperparathyroidism (PHPT). MGD is associated with hereditary PHPT, but the sporadic MGD is more common and affects a similar patient profile as single gland parathyroid disease (SGD). The distinction between SGD and MGD is of great clinical importance, especially for the strategy of parathyroidectomy. Based on the limited knowledge available, MGD is likely to be a genetically heterogeneous disease resulting from the interaction of germline and somatic DNA mutations together with epigenetic alterations. Furthermore, these events may combine and occur independently in parathyroid tumors within the same individual with MGD. Gene expression profiling has shown that SGD and MGD may represent distinct entities in parathyroid tumorigenesis. We are waiting for studies to analyze exactly which genes are different in SGD and MGD in order to identify potential biomarkers that can distinguish between the two forms of the disease.

A contemporary analysis of the pre- and intraoperative recognition of multigland parathyroid disease

BACKGROUND

Despite advances in biochemical and radiological identification of parathyroid gland enlargement, primary hyperparathyroidism (PHPT) due to sporadic multigland parathyroid disease (MGPD) remains a perioperative diagnostic dilemma. Failure to recognise MGPD pre- or intraoperatively may negatively impact surgical cure rates and result in persistent PHPT and ongoing patient morbidity.

METHODS

We have conducted a comprehensive review of published literature in attempt to determine factors that could aid in reliably diagnosing sporadic MGPD pre- or intraoperatively. We discuss preoperative clinical features and examine pre- and intraoperative biochemical and imaging findings concentrating on those areas that give practicing surgeons and the wider multi-disciplinary endocrine team indications that a patient has MGDP. This could alter surgical strategy.

CONCLUSION

Biochemistry can provide diagnosis of PHPT but cannot reliably discriminate parathyroid pathology. Histopathology can aid diagnosis between MGPD and adenoma, but histological appearance can overlap. Multiple negative imaging modalities indicate that MGPD may be more likely than a single parathyroid adenoma, but the gold standard for diagnosis is still intraoperative identification during BNE. MGPD remains a difficult disease to both diagnose and treat.

Primary Adenoma Arising From Two Ipsilateral Supernumerary Inferior Parathyroid Adenomas

A single parathyroid adenoma is the most common cause of primary hyperparathyroidism (PHPT). However, multiple synchronous adenomas can be found at surgery. More uncommon are ipsilateral synchronous adenomas, and that combined with a supernumerary gland, is even more rare. Here we present a case of PHPT due to an ipsilateral double adenoma of the inferior parathyroid gland, which was supernumerary. The diagnosis was made preoperatively by ultrasonography; however, sestamibi scan showed only a single hyperfunctioning gland on the left side. This was further substantiated by the use of intraoperative parathyroid hormone (PTH) monitoring, wherein PTH levels decreased to less than 50% of preoperative values only after the complete removal of the second adenomatous gland. This case report highlights the importance of preoperative localization and intraoperative PTH monitoring in evaluating patients with PHPT in the setting of multiple synchronous parathyroid adenoma.

[The role of calcium sensitive and vitamin D receptors in the pathogenesis of sporadic multiple parathyroid gland disease]

BACKGROUND

Sporadic multiple parathyroid gland disease is ¼ cases of primary hyperparathyroidism (PHPT). However, a single tactic for diagnosing and operating volume in patients with this variant of PHPT has not yet been developed. One of the possible directions in the search for pathogenetically substantiated methods of diagnosis and treatment is the study of the molecular genetic features of the disease and associated clinical and laboratory factors.

AIM

To study the features of the expression of calcium sensitive (CaSR) and vitamin D (VDR) receptors on the surface of parathyroid cells in primary hyperparathyroidism with solitary and multiple lesions of the parathyroid glands, as well as its changes under the influence of a decrease in the filtration function of the kidneys.

MATERIALS AND METHODS

In a single center observational prospective study with retrospective data collection, there were patients who during 2019-2021. operated on for PHPT, secondary hyperparathyroidism (SHPT) and all cases of tertiary hyperparathyroidism (THPT) operated during 2014-2021. The expression of CaSR, VDR and its relationship with the main laboratory parameters, the clinical variant of hyperparathyroidism, and the morphological substrate were studied.

RESULTS

The study included 69 patients: 19 with multiple and 25 with solitary PTG near PHPT, 15 with SHPT, 10 with THPT. A statistically significant decrease in the frequency of detection of normal expression of CaSR and VDR receptors occurs in any morphological variant of hyperparathyroidism and is observed in 93-60% of drugs. A decrease in the normal expression of CaSR in hyperplasia is detected statistically significantly less frequently than in adenoma (p≤0.01). The median expression intensity in adenoma was 2.5 (2:3), in hyperplasia 3.5 (3-4) (p≤0.01). The difference in the molecular mechanisms of the development of hyperparathyroidism with a predominance of a morphological substrate in the form of adenoma (PHPT with solitary adenoma) or hyperplasia (SHPT and PHPT with multiple PTG lesions) is realized in the frequency of maintaining normal CaSR expression in the PTG tissue. These mechanisms are implemented at the local level, their variability does not change under the influence of RRT. A common molecular genetic mechanism for the development of hyperparathyroidism with a predominance of a morphological substrate in the form of adenoma or hyperplasia has been found to reduce the frequency of maintaining normal VDR expression in PTG (up to 7-13%), p<0.01. This mechanism is implemented at the local level, its variability changes under the influence of RRT, reaching statistically significant differences in patients with THPT.

CONCLUSION

The study demonstrates the features of changes in the expression of CaSR and VDR in PHPT with multiple lesions of the parathyroid glands. The relationship between the expression of these receptors and the clinical variant of hyperparathyroidism, the morphological substrate, the main laboratory parameters, and renal function was shown.

Preoperative, Intraoperative, and Postoperative Parathyroid Pathology: Clinical Pathologic Collaboration for Optimal Patient Management

Parathyroid disease typically presents with parathyroid hyperfunction as result of neoplasia or a consequence of non-neoplastic systemic disease. Given the parathyroid gland is a hormonally active organ with broad physiologic implications and serologically accessible markers for monitoring, the diagnosis of parathyroid disease is predominantly a clinical pathologic correlation. We provide the current pathological correlates of parathyroid disease and discuss preoperative, intraoperative, and postoperative pathology consultative practice for optimal patient care.

The utility of intraoperative PTH dosage in primary hyperparathyroidism based on preoperative diagnosis and surgical choice

BACKGROUND

The aim of this study was to evaluate the impact of the intraoperative PTH (ioPTH) monitoring in the success of parathyroidectomy based on the concordant or indeterminate preoperative imaging studies of localization and the performed surgical choices.

METHODS

Fourthy-seven patients who received parathyroidectomy operations were divided in four groups: concordance of the imaging and ioPTH, concordance of the imaging and no ioPTH, indeterminate imaging and ioPTH and indeterminate imaging and no ioPTH.

RESULTS

Overall, patients in whom ioPTH monitoring was not performed were healed in 89.47% of cases, while the percentage of recovery in patients receiving ioPTH was 85.71%. There were no differences in the changes in strategy or in the cure rates with the use of ioPTH.

CONCLUSIONS

No significant differences were found, independently from the preoperative imaging agreement, in either the cure rate or in the change of intraoperative strategy using the ioPTH dosage.

Persistent and Recurrent Primary Hyperparathyroidism: Etiological Factors and Pre-Operative Evaluation

Primary hyperparathyroidism (pHPT) is the most common cause of hypercalcemia and currently the only definitive treatment is surgery. Although the success rate of parathyroidectomy is over 95% in experienced centers, surgical failure is the most common complication today. Persistent HPT (perHPT) is defined as persistence of hypercalcemia after parathyroidectomy or recurrence of hypercalcemia within the first 6 months, and recurrence of hypercalcemia after a normocalcemic period of more than 6 months is defined as recurrent HPT (recHPT). In the literature, perHPT is reported to be 2-22%, and the rate of recHPT is 1-15%. perHPT is often associated with misdiagnosed pathology or inadequate resection of hyperfunctioning parathyroid tissue, recHPT is associated with newly developing pathology from potentially pathologically natural tissue left in situ at the initial surgery. In the pre-operative evaluation, the initial diagnosis of pHPT and the diagnosis of perHPT or rec HPT should be confirmed in patients who are evaluated with a pre-diagnosis (suspect) of perHPT and recHPT. Surgery is recommended if it meets any of the recommendations in surgical guidelines, as in patients with pHPT, and there are no surgical contraindications. The first preoperative localization studies, surgical notes, operation drawings, if any, intraoperative PTH results, pathological results, and post-operative biochemical results of these patients should be examined. Localization studies with preoperative imaging methods should be performed in all patients with perHPT and recHPT with a confirmed diagnosis and surgical indication. The first-stage imaging methods are ultrasonography and Tc99m sestamibi single photon tomography Tc99mMIBI SPECT or hybrid imaging method, which is combined with both single-photon emission computed tomography and computed tomography (SPECT/CT). The combination of USG and sestamibi scintigraphy increases the localization of the pathological gland. In the secondary stage, Four-Dimensional computer tomography (4D-CT) or dynamic 4-dimensional Magnetic Resonance Imaging (4D-MRI) can be applied. It is focused on as a secondary stage imaging method, especially when the lesion cannot be detected by conventional methods. Positron Emission Tomography (PET) and PET/CT examinations with 11C-choline or 18F-fluorocholine are promising imaging modalities. Invasive examinations can rarely be performed in patients in whom suspicious, incompatible or pathological lesion cannot be detected in noninvasive imaging methods. Bilateral jugular vein sampling, selective venous sampling, parathyroid arteriography, imaging-guided fine-needle aspiration biopsy, and parathormone washout are invasive methods.

Clinical features of sporadic multigland parathyroid disease

Background. Sporadic multigland parathyroid disease (MGD) account for 1/4 of all cases of primary hyperparathyroidism (PHPT). There are no specific signs of MGD in comparison with single-gland parathyroid disease in PHPT. The only radical treatment is surgical, therefore, determining the number of excessively functioning parathyroid glands at the preoperative stage is important for choosing the extent of the operation and the success of the treatment in general.The aim. To identify the specific signs of multigland parathyroid disease in patients who underwent surgery for primary hyperparathyroidism. Methods. We conducted a single-center prospective study including 126 cases of surgical treatment of PHPT from December 2019 to June 2021. The study included an analysis of demographic, clinical, laboratory parameters and visual methods of topical diagnosis of parathyroid glands (ultrasound, scintigraphy, multislice computed tomography). The main endpoint of the study was the identification of characteristic signs of MGD in patients with PHPT.Results. Lower values of creatinine (p ≤ 0.01; Mann – Whitney U-test), albuminadjusted calcium (p ≤ 0.05; Mann – Whitney U-test), parathyroid hormone (p ≤ 0.01; Mann – Whitney U-test), glomerular filtration rate (p ≤ 0.01; Mann – Whitney U-test) and inconsistency of two methods of preoperative imaging (p ≤ 0.01; χ2) were set as specific signs of multigland compared with single-gland parathyroid disease. Conclusion. The results of preoperative biochemical and imaging studies can become the basis for differentiating single-gland and multigland parathyroid disease in primary hyperparathyroidism.

Clinical application of endoscopic surgery using a gasless unilateral transaxillary approach in the treatment of primary hyperparathyroidism

Objectives

To investigate the safety and feasibility of gasless axillary parathyroid surgery in the treatment of primary hyperparathyroidism.

Methods

A total of 12 patients who received gasless axillary parathyroidectomy (endoscope group) and 14 patients who received traditional open parathyroidectomy (open group) from January 2019 to April 2022 were screened and included. The differences in baseline characteristics, surgical efficiency, incidence rate of complications, changes in biochemical indicators, and incision satisfaction between the two groups were analyzed and compared.

Results

The proportion of young patients was higher in the endoscopic group than in the open group, and the difference was statistically significant [(41.33 ± 13.65) years vs. (58.00 ± 9.44) years, P < 0.01]. The differences in operation time, intra-operative blood loss, post-operative drainage volume, hospital stay, and surgical efficiency between the two groups yielded no statistical significance (P > 0.05). Patients in the open group had more significant neck pain 3 days after surgery (P = 0.046), but the degree of pain 3 months after surgery was the same in the 2 groups (P = 0.432). Evaluation of post-operative mature stage scar and incision satisfaction regarding aesthetics in the endoscope group were significantly superior to that in the open group [(1.92 ± 0.92) points vs. (0.92 ± 1.00) points, P = 0.017 and (1.57 ± 0.51) points vs. (1.00 ± 0.013) points, P = 0.013, respectively]. No statistical significance was found in terms of incidence rate of post-operative fever (P > 0.05). No temporary recurrent laryngeal nerve injury, post-operative bleeding, incision hematoma infection, or other complications were observed. Comparing the two groups, the extent of the level decrease of PTH was similar to that of serum calcium and phosphorus (P < 0.05), where most patients experienced transient hypocalcemia after operation yielding no significant difference in incidence (P = 0.225). During a follow-up period of 3 to 36 months, a total of 1 patient in the open group experienced recurrence at 10 months after surgery and was treated non-surgically.

Conclusion

Gasless axillary approach to parathyroid surgery for primary hyperparathyroidism possesses good safety and patient satisfaction in terms of aesthetics.

Contribution of intraoperative parathyroid hormone monitoring to the surgical success in minimal invasive parathyroidectomy

Background

The contribution of intraoperative parathyroid hormone monitoring to minimally invasive parathyroidectomy remains controversial. We aimed to evaluate whether intraoperative parathyroid hormone monitoring monitoring could contribute to minimally invasive parathyroidectomy in these patients.

Methods

The data of the patients whose preoperative ultrasonography and technetium-99 m sestamibi scintigraphy imagings were positive and concordant for one gland and who underwent minimally invasive parathyroidectomy between 2003 and 2018 in our clinic, were evaluated retrospectively. Blood samples were collected at pre-excisional period, and at post-excisional 10 and 20 min; the intaoperative parathyroid hormone was measured, and the surgery was terminated without waiting for the result. Patients were divided into 2 groups according to the postoperative results, as those with normocalcemia (Group 1) and those with persistence (Group 2).

Results

There were 195 patients in Group 1 and 14 patients in Group 2. The cure rate at the first surgery was 93.3%. Cure was achieved after the second operation in all patients in Group 2. Recurrent disease developed in 1 patient in group 1 and the overall cure rate was 99.5%. If intraoperative parathyroid hormone had been evaluated, cure could have been achieved at the first surgery with additional exploration, in 10 (71.4%) of 14 patients according to the insufficient decrease in parathyroid hormone value at the 10 min in Group 2, and in 9 (64.3%) of 14 patients according to the parathyroid hormone value at 20 min. However, due to insufficient decrease (false negative) in the parathyroid hormone value at the 10 and 20 min the rate of false negatives and unnecessary exploration would be 9.5% and 2.5%, respectively. With additional exploration, the cure rate in the first surgery could be increased by 4.3%–97.6% according to the 20 min intraoperative parathyroid hormone value.

Conclusion

The cure rate in minimally invasive parathyroidectomy can be increased by minimizing unnecessary conversion to bilateral neck exploration, by evaluating intraoperative parathyroid hormone at 10 min in patients with positive and concordant scans, and intraoperative parathyroid hormone at 20 min in patients with inadequate decrease at 10 min intraoperative parathyroid hormone.

Multiglandular Parathyroid Disease

Introduction: Multiglandular parathyroid disease (MGD) is an uncommon cause of primary hyperparathyroidism (pHPT) and has been reported in the literature in 8–33% of patients with pHPT. The aim of our study was to review the clinical characteristics and management of MGD and evaluation of surgical treatment failures. Methods: We performed a retrospective study of 163 patients with pHPT undergoing parathyroidectomy (PTX) at the Department of General and Endocrine Surgery between 1983 and 2018. All these patients were diagnosed with MGD. This group of patients was compared with a group of 856 patients with solitary disease operated for pHPT in the same period. Results: Among 163 patients—127 (79%) of them had two lesions, 28 (16%) had three, and 8 (5%) four. They were prevalently women over the age of 50. The diagnosis was based on PTH and ionized calcium studies and used sestamibi technetium-99m scintigraphy (MIBI) as well for us. Treatment was surgical. Conclusions: Parathyroidectomy (PTX) for multiglandular parathyroid disease (MGD) is associated with a higher operative risk of failure compared to solitary disease. Preoperative diagnosis and localization of the parathyroid glands is an extremely important element of treatment. Diagnosis is based on PTH and calcium levels. Ultrasonography (USG), MRI, and scintigraphy are very helpful in diagnosis. Mediastinal multiglandular parathyroid disease (MGD) is associated with increased surgical treatment failures. The treatment is surgical and consists of the removal of the masses or complete parathyroidectomy. Based on this study, we support the existence of multiple adenomas and advocate the removal of only macroscopically enlarged parathyroid glands in patients with primary hyperparathyroidism.

[Role of preoperative visualization in the choice of surgery for primary hyperparathyroidism]

BACKGROUND

Precise localization of abnormal parathyroid glands is important for a successful surgery for primary hyperparathyroidism (PHPT). While a large number of patients can be successfully treated with the focused parathyroidectomy, there is a considerable rate of the persistent PHPT mostly because of undetected multiglandular disease (MGD).

AIM

The aim of the study was to evaluate the meaning of preoperative visualization data for planning the surgery for patients with PHPT.

MATERIALS AND METHODS

The study was conducted at SPBU Hospital in 2017-2018. 810 patients who underwent a primary surgery for PHPT were included in the study. Preoperative imaging results were investigated and multivariative logistic regressions were calculated to assess the predictive values of preoperative data. The rate of cases with persistent disease and cases with MGD were compared between patients with different results of preoperative data.

RESULTS

Age, sex, body mass index, negative results of preoperative US, MIBI and 4D CT were not independently associated with the higher risk of multiglandular disease. The larger number of performed preoperative visualization studies were associated with the higher risk of persistence. 37% cases of MGD were not identified preoperatively. There were 7 cases with previously unsuspected second adenomas found only due to bilateral neck exploration.

CONCLUSION

Any combination of preoperative visualization modalities was not able to rule out the MGD reliably. Efficacy of surgical treatment was not associated with the higher number of preoperative studies. Bilateral neck exploration may decrease the rate of the persistent hyperparathyroidism improving the identification of multiglandular disease.

Primary hyperparathyroidism, a machine learning approach to identify multiglandular disease in patients with a single adenoma found at preoperative Sestamibi-SPECT/CT

OBJECTIVE

Successful preoperative image localisation of all parathyroid adenomas (PTA) in patients with primary hyperparathyroidism (pHPT) and multiglandular disease (MGD) remains challenging. We investigate whether a machine learning classifier (MLC) could predict the presence of overlooked PTA at preoperative localisation with 99mTc-Sestamibi-SPECT/CT in MGD patients.

DESIGN

This study is a retrospective study from a single tertiary referral hospital initially including 349 patients with biochemically confirmed pHPT and cured after surgical parathyroidectomy.

METHODS

A classification ensemble of decision trees with Bayesian hyperparameter optimisation and five-fold cross-validation was trained with six predictor variables: the preoperative plasma concentrations of parathyroid hormone, total calcium and thyroid-stimulating hormone, the serum concentration of ionised calcium, the 24-h urine calcium and the histopathological weight of the localised PTA at imaging. Two response classes were defined: patients with single-gland disease (SGD) correctly localised at imaging and MGD patients in whom only one PTA was localised on imaging. The data set was split into 70% for training and 30% for testing. The MLC was also tested on a subset of the original data based on CT image-derived PTA weights.

RESULTS

The MLC achieved an overall accuracy at validation of 90% with an area under the cross-validation receiver operating characteristic curve of 0.9. On test data, the MLC reached a 72% true-positive prediction rate for MGD patients and a misclassification rate of 6% for SGD patients. Similar results were obtained in the testing set with image-derived PTA weight.

CONCLUSIONS

Artificial intelligence can aid in identifying patients with MGD for whom 99mTc-Sestamibi-SPECT/CT failed to visualise all PTAs.

Multiglandular Parathyroid Disease in Primary Hyperparathyroidism With Inconclusive Conventional Imaging

Inconclusive preoperative imaging is a strong predictor of multiglandular parathyroid disease (MGD) in patients with primary hyperparathyroidism (PHPT). MGD was investigated in a cohort of 17 patients with PHPT (mean age 64.9 years, total calcium 2.75 mmol/l and parathyroid hormone (PTH) 113.3 ng/l) who underwent 18F-fluorocholine PET/CT (FCH) imaging before surgery. The initial MIBI SPECT scintigraphy (MIBI) and/or neck ultrasound were not conclusive or did not localize all pathological parathyroid glands, and PHPT persisted after surgery. Sporadic MGD was present in 4 of 17 patients with PHPT (24 %). In 3 of 4 patients with MGD, FCH correctly localized 6 pathological parathyroid glands and surgery was successful. Excised parathyroid glands were smaller (p <0.02) and often hyperplastic in MGD than in single gland disease. In two individuals with MGD, excision of a hyperplastic parathyroid gland led to a false positive decline in intraoperative PTH and/or postoperative serum calcium. Although in one patient it was associated with partial false negativity, parathyroid imaging with FCH seemed to be superior to neck ultrasound and/or MIBI scintigraphy in MGD.

GCM2 Variants in Familial and Multiglandular Primary Hyperparathyroidism

CONTEXT

Multiglandular and familial parathyroid disease constitute important fractions of primary hyperparathyroidism (PHPT). Germline missense variants of GCM2, a regulator of parathyroid development, were observed in familial isolated hyperparathyroidism and sporadic PHPT. However, as these previously reported GCM2 variants occur at relatively high frequencies in the population, understanding their potential clinical utility will require both additional penetrance data and functional evidence relevant to tumorigenicity.

OBJECTIVE

Determine the frequency of GCM2 variants of interest among patients with sporadic multigland or familial parathyroid disease and assess their penetrance.

DESIGN AND PATIENTS

DNA-encoding PHPT-associated GCM2 germline variants were polymerase chain reaction-amplified and sequenced from 107 patients with either sporadic multigland or suspected/confirmed familial parathyroid tumors.

RESULTS

GCM2 variants were observed in 9 of 107 cases (8.4%): Y282D in 4 patients (6.3%) with sporadic multigland disease; Y394S in 2 patients (11.1%) with familial PHPT and 3 (4.8%) with sporadic multigland disease. Compared with the general population, Y282D was enriched 5.9-fold in multigland disease, but its penetrance was very low (0.02%). Y394S was enriched 79-fold in sporadic multigland disease and 93-fold in familial PHPT, but its penetrance was low (1.33% and 1.04%, respectively).

CONCLUSIONS

Observed in vitro-activating GCM2 variant alleles are significantly overrepresented in PHPT patients with multiglandular or familial disease compared to the general population, yet penetrance values are very low; that is, most individuals with these variants in the population have a very low risk of developing PHPT. The potential clinical utility of detecting these GCM2 variants requires further investigation, including assessing their possible role as pathogenic/low-penetrance alleles.

Triple water clear cell parathyroid adenomas: a rare cause of primary hyperparathyroidism

A man in his 70s was referred to the endocrine surgery department after incidental finding of hypercalcaemia during preoperative work-up for abdominal aortic aneurysm repair. The patient reported severe fatigue and malaise with no previous history of nephrolithiasis or osteoporosis. After biochemical confirmation of primary hyperparathyroidism, localisation studies suggested multiple gland disease. Intraoperatively, three enlarged parathyroid adenomas were found and excised. Histopathological and immunohistochemical examination revealed triple water clear cell (WCC) parathyroid adenomas. Adenomas being entirely composed of WCCs are rare. In addition, triple adenomas are so rare that their existence is disputed by some authors. The present paper reports on an extremely rare case of a patient suffering from triple parathyroid adenomas composed entirely of WCCs. To our knowledge, this is the first such reported case in the English language literature.

Contemporary Management of Primary Hyperparathyroidism

Primary hyperparathyroidism can be asymptomatic or symptomatic, as well as classic, normocalcemic, or normohormonal. It is important to rule out other causes of hypercalcemia or hyperparathyroidism. Preoperative localization with imaging is necessary for a minimally invasive approach and can be helpful even if planning 4-gland exploration. There are a variety of intraoperative techniques that can assist with localization as well as confirming success. Standard of care remains surgical resection of affected glands. However, there are less invasive management strategies that can be considered for poor surgical candidates.

[Sporadic primary hyperparathyroidism with multiple parathyroid adenomas]

Multiple lesions of the parathyroid glands (PTG) in primary hyperparathyroidism (PHPT) can be sporadic or develop as part of hereditary syndromes, manifesting at young age. There the description of a severe sporadic PHPT with big parathyroid neoplasms in the young patient is presented. Clinical data made it possible to suspect MEN-1 syndrome or parathyroid carcinomas; however, mutations CDKN, CDC73, MEN1 were excluded. The patient underwent removal of three identified tumors: benign adenomas of the left PTG and hyperplasia of the right one. Postoperative hypocalcemia and severe hungry bone syndrome required the administration of vitamin D and calcium carbonate preparations. However, a year after the operation, a «mild» recurrent disease was confirmed. Taking into account the patient's refusal to reoperation and a significant improvement of the target organs state, active observation was continued. The patient needs further careful dynamic monitoring by specialists in order to timely identify indications for repeated surgical treatment to improve the life quality and span.

The role of Rapid Intraoperative Parathyroid Hormone (ioPTH) assay in determining outcome of parathyroidectomy in primary hyperparathyroidism: A systematic review and meta-analysis

BACKGROUND

Primary hyperparathyroidism (PHPT) is a common endocrine disorder. In the last few decades, the introduction of Rapid Intraoperative Parathyroid Hormone (ioPTH) monitoring has allowed to ensurance of the excision of all hyperfunctioning parathyroid tissues, reducing the risks of persistent and recurrent PHPT. However, the use of ioPTH is still debated among endocrine surgeons.

MATERIAL AND METHODS

The objective of this systematic review and meta-analysis was to assess if ioPTH monitoring is able to reduce the incidence of persistent or recurrent PHPT. A systematic literature search was performed using PubMed, Scopus, ISI-Web of Science and Cochrane Library Database. Prospective and retrospective studies addressing the efficacy of ioPTH monitoring were included in the systematic review and meta-analysis. The random-effects model was assumed to account for different sources of variation among studies. The overall effect size was computed through the inverse variance method. Heterogeneity across studies, possible outlier studies, and publication bias were evaluated.

RESULTS

A total of 28 studies with 13,323 patients were included in the quantitative analysis. The incidence of operative failure was 3.2% in the case group and 5.8% in the control group. After excluding three outlier studies, the quantitative analysis revealed that ioPTH reduced significantly the incidence of postoperative persistent or recurrent PHPT. (Risk Difference = -0.02; CI = -0.03, -0.01; p < 0.001). There was no evidence of heterogeneity among the studies (Q = 19.92, p = 0.70; I² = 0%). The analysis of several continuous moderators revealed that the effectiveness of ioPTH was larger in studies with lower preoperative serum calcium values and higher incidences of multiple gland disease.

CONCLUSION

ioPTH monitoring is effective in reducing the incidence of persistent and recurrent PHPT. Its routine use should be suggested in the next guidelines regarding management of PHPT.

Primary Hyperparathyroidism: Defining the Appropriate Preoperative Imaging Algorithm

Primary hyperparathyroidism is a common and potentially debilitating endocrine disorder for which surgery is the only curative treatment. Preoperative imaging is always recommended, even in cases of conventional bilateral neck exploration, with a recognized role for 99mTc-sestamibi scintigraphy in depicting ectopic parathyroid lesions. Scintigraphy can also play a major role in guiding a targeted, minimally invasive parathyroidectomy. However, the ability to recognize multiple-gland disease (MGD) varies greatly depending on the imaging protocol used. Preoperative diagnosis of MGD is important to reduce the risks of conversion to bilateral surgery or failure. In this article we discuss imaging strategies before first surgery as well as in the case of repeat surgery for persistent or recurrent primary hyperparathyroidism. We describe a preferred algorithm and alternative options. Dual-tracer 99mTc-sestamibi/123I subtraction scanning plus neck ultrasound is the preferred first-line option. This approach should improve MGD detection and patient selection for minimally invasive parathyroidectomy. Second-line imaging procedures in case of negative or discordant first-line imaging results are presented. High detection rates can be obtained with 18F-fluorocholine PET/CT or with 4-dimensional CT. The risk of false-positive results should be kept in mind, however. Adding a contrast-enhanced arterial-phase CT acquisition to conventional 18F-fluorocholine PET/CT can be a way to improve accuracy. We also briefly discuss other localization procedures, including 11C-methionine PET/CT, MRI, ultrasound-guided fine-needle aspiration, and selective venous sampling for parathyroid hormone measurement.

Pediatric hyperparathyroidism: review and imaging update

Hyperparathyroidism, due to increased secretion of parathyroid hormones, may be primary, secondary or tertiary. Most pediatric patients with sporadic primary hyperparathyroidism will be symptomatic, presenting with either end-organ damage or nonspecific symptoms. In younger patients with primary hyperparathyroidism, there is a higher prevalence of familial hyperparathyroidism including germline inactivating mutations of the calcium-sensing receptor genes that result in either neonatal severe hyperparathyroidism or familial hypocalciuric hypercalcemia. Parathyroid scintigraphy and ultrasound are complementary, first-line imaging modalities for localizing hyperfunctioning parathyroid glands. Second-line imaging modalities are multiphase computed tomography (CT) and magnetic resonance imaging. In pediatrics, multiphase CT protocols should be adjusted to optimize radiation dose. Although, the role of these imaging modalities is better established in preoperative localization of hyperfunctioning parathyroid glands in primary hyperparathyroidism, the same principles apply in secondary and tertiary hyperparathyroidism. In this manuscript, we will review the embryology, anatomy, pathophysiology and preoperative localization of parathyroid glands as well as several subtypes of primary familial hyperparathyroidism. While most of the recent imaging literature centers on adults, we will focus on the issues that are pertinent and applicable to pediatrics.

Preoperative imaging predicts change in bone mineral density after parathyroidectomy for primary hyperparathyroidism

BACKGROUND

Bone Mineral Density (BMD) improves after parathyroidectomy (PTX), but data on factors that predict bone recovery are limited. No studies have evaluated if preoperative imaging findings are associated with postoperative change in BMD. We hypothesized that larger, metabolically active glands would be associated with greater increase in BMD after PTX.

METHODS

Patients with primary hyperparathyroidism (PHPT) who underwent combined Tc-99m sestamibi and 4D-CT imaging prior to PTX and had pre- and post-operative dual-energy X-ray absorptiometry (DXA) at our institution were considered for inclusion. Retrospectively, data were collected from imaging studies on each parathyroid gland, including estimated weight (using the ellipsoid formula) and contrast enhancement on 4D-CT as well as sestamibi avidity. Total estimated parathyroid weight was calculated. The main outcome measure was the percent change in BMD at the lumbar spine (LS) from pre- to post-operative DXA. Predictors of change in BMD at the LS were assessed.

RESULTS

Complete DXA data was available in 25 patients. Median total parathyroid weight on 4D-CT was 270 mg, and mean change in BMD at the LS was 2.4 ± 4.3%. The increase in BMD was best predicted by higher preoperative serum calcium (p = 0.01), greater estimated parathyroid weight (p = 0.001), sestamibi avidity (p = 0.03), and increased time between DXA scans (p = 0.03) in the multivariable model (R² = 0.79, p < 0.0001).

CONCLUSION

In PHPT, higher preoperative serum calcium, parathyroid gland weight on imaging, and sestamibi avidity are associated with greater increases in BMD after curative PTX. These findings suggest that larger, metabolically active adenomas may mobilize more calcium from bone.

Usefulness of the Wisconsin and CaPTHUS indices for predicting multiglandular disease in patients with primary hyperparathyroidism in a southern European population

Background

Focused parathyroidectomy is a safe technique for the treatment of primary hyperparathyroidism. The CaPTHUS score and the Wisconsin index are preoperative diagnostic tools designed to distinguish between single- and multigland disease. The aim of the study is to evaluate the usefulness of these models for predicting multiglandular disease in a European population.

Methods

Retrospective review of a database of patients operated upon for primary hyperparathyroidism at a referral center. The sensitivity, specificity, positive and negative predictive values, and reliability of both scores for the prediction of multiglandular disease, were calculated. Receiver operating characteristic (ROC) curves were constructed to assess the sensitivity and specificity of CaPTHUS score and Wisconsin Index for predicting single-gland disease. A level of P<0.05 was accepted as significant.

Results

Two hundred and eighty-one patients who underwent successful surgery from January 2001 to December 2018 were included. Single-gland disease was detected in 92.5%, and 73.7% had a CaPTHUS score of ≥3. The sensitivity, specificity, positive and negative predictive values of this model for predicting single-gland disease with a score of ≥3 were 76.9%, 66.7%, 96.6%, and 18.9% respectively. The area under the curve value of the CaPTHUS score for predicting single-gland disease was 0.74. A Wisconsin Index >2,000 and an excised gland weight above one gram presented a positive predictive value for single-gland disease of 92.5%.

Conclusions

Despite the good performance of both scales, the established cut-off points did not definitively rule out parathyroid multiglandular disease in our population. In cases with a minimal suspicion of this condition, additional intraoperative techniques must be used, or bilateral neck explorations should be performed.

Will 18F-fluorocholine PET/CT replace other methods of preoperative parathyroid imaging?

INTRODUCTION

Primary hyperparathyroidism (PHPT) is a common endocrine disorder usually due to hyperfunctioning parathyroid glands (HPs). Surgical removal of the HPs is the main treatment for PHPT, making the correct detection and localization of HPs crucial to guiding targeted and minimally invasive surgical treatment in patients with PHPT. To date, different imaging methods have been used to detect and localize HPs, including radiology, nuclear medicine, and hybrid techniques.

METHODS

The present work discusses the role and value of different imaging methods in PHPT and, particularly, evaluates the potential role of ¹⁸F-fluorcholine PET/CT as a "one-stop-shop" method for preoperative parathyroid localization in patients with PHPT.

DISCUSSION

Cervical ultrasound (US) and parathyroid scintigraphy using ^99mTc-MIBI are the most commonly employed methods in clinical practice. More recently, four-dimensional computed tomography (4D CT) and positron emission tomography (PET) with radiolabeled choline have emerged as useful alternatives in cases of negative or discordant findings from first-line imaging methods.

CONCLUSIONS

Due to the excellent diagnostic performance of radiolabeled choline PET/CT and the low radiation burden, this technique seems to be an ideal candidate to substitute current imaging procedures including US, MIBI scintigraphy, 4D CT and MRI and perform a fast and reliable "one-stop-shop" preoperative localization of HP in patients with PHPT, including challenging cases of postoperative persistent/recurrent disease.

Selection of parathyroidectomy methods for primary hyperparathyroidism according to concordance between ultrasonography and MIBI scan results

Background

Determination of appropriate operative methods for primary hyperparathyroidism (PHPT) is difficult when localisation results are discordant between imaging studies. The aim of this study was to compare the efficacy of focused parathyroidectomy (FP) and bilateral neck exploration (BNE) according to the concordance in localisation results.

Method

One hundred and ninety-one patients who underwent a PHPT operation at Asan Medical Center between 2000 and 2010 were divided into two groups according to the concordance in findings between neck ultrasonography (USG) and sestamibi (MIBI) scan. Differences in clinicopathological features and surgical outcomes between the concordant (n=137) and discordant (n=54) groups were analysed.

Results

FP and BNE did not show significant differences in postoperative persistent hyperparathyroidism rates. Although intraoperative parathyroid hormone (IOPTH) monitoring was not performed in this study, the cure rates of PHPT using only USG and MIBI scans were satisfactorily high, at 98.5% in the concordant group and 96.3% in the discordant group. The cure rates of FP and Unilateral exploration in single-negative USG and MIBI scans were 100%. Multiple lesions and hyperplasia were more common in the discordant group.

Conclusions

In cases where it is difficult to apply IOPTH, FP without IOPTH is feasible in patients showing concordant or single-negative detection on USG and MIBI scans, whereas BNE is recommended in cases of discordance or double-negative results on imaging studies, to prevent recurrence or persistent disease. Appropriate selection of parathyroidectomy methods according to the concordance in USG and MIBI scans might produce good results without any difference in recurrence.

Factors related to a non-localising technetium 99m sestamibi scan result during parathyroid adenoma imaging in primary hyperparathyroidism

OBJECTIVES

The aim of this study is to investigate factors that are associated with having a non-localising ^99m Tc-sestamibi scan.

DESIGN

A retrospective study was performed on patients that underwent parathyroid surgery performed within a single institution between 2001 and 2018.

SETTING

Single tertiary centre for parathyroid surgery.

PARTICIPANTS

230 patients underwent surgery for primary hyperparathyroidism due to a solitary parathyroid adenoma and had preoperative ^99m Tc-sestamibi imaging.

MAIN OUTCOME MEASURES

Variables including age, gender, intra-operative location of parathyroid adenoma, adenoma weight and pre- and postoperative calcium and parathyroid hormone levels were investigated through univariate and multivariate analysis to identify any association with having a non-localising (negative) ^99m Tc-sestamibi scan result.

RESULTS

Multivariate analysis identified that right-sided adenomas (P = .038), superior adenomas (P = .042) and a lower preoperative PTH level (P = .034) were all individual factors associated with having a negative ^99m Tc-sestamibi scan result. Although the weight of the adenoma was significant on univariate analysis (P = .029), this was not demonstrated on multivariate analysis (P = .422).

CONCLUSION

Factors that were associated with having non-localising ^99m Tc-sestamibi scan were right-sided adenomas, superior adenomas and lower preoperative PTH level. Further large prospective multicentre studies are needed to further evaluate these initial findings.

Lithium-associated hyperparathyroidism

Lithium is a mood stabiliser widely used in the treatment and prophylaxis of mania, bipolar disorders and recurrent depression. Treatment with lithium can give rise to various endocrine and metabolic abnormalities, including thyroid dysfunction, nephrogenic diabetes insipidus and hypercalcaemia. Lithium may induce hypercalcaemia through both acute and chronic effects. The initial acute effects are potentially reversible and occur as a result of lithium's action on the calcium-sensing receptor pathway and glycogen synthase kinase 3, giving rise to a biochemical picture similar to that seen in familial hypocalciuric hypercalcaemia. In the long term, chronic lithium therapy leads to permanent changes within the parathyroid glands by either unmasking hyperparathyroidism in patients with a subclinical parathyroid adenoma or possibly by initiating multiglandular hyperparathyroidism. The latter biochemical picture is identical to that of primary hyperparathyroidism. Lithium-associated hyperparathyroidism, especially in patients on chronic lithium therapy, is associated with increased morbidity. Hence, regular monitoring of calcium levels in patients on lithium therapy is of paramount importance as early recognition of lithium-associated hyperparathyroidism can improve outcomes. This review focuses on the definition, pathophysiology, presentation, investigations and management of lithium-associated hyperparathyroidism.

Surgical treatment of double parathyroid adenomas in primary hyperparathyroidism: A clinical case

•

Double adenomas in primary hyperparathyroidism are a difficult diagnostic and therapeutic task.

•

A comprehensive and thorough assessment of all methods for visualization of the parathyroid glands at the preoperative stage.

•

Double adenomas require a bilateral neck audit with a visual assessment of all parathyroid glands.

•

A positive test during intraoperative monitoring of iPTH does not exclude a double adenoma in a patient.

Introduction

The frequency of occurrence of double parathyroid adenomas in patients with primary hyperparathyroidism is from 2 to 11% of cases. Nowadays, double adenomas remain a difficult diagnostic and therapeutic task.

Presentation of case

A 64-year-old woman was referred to an endocrine surgeon to evaluate a persistently elevating level of calcium. In the biochemical analysis the serum level of total calcium was increased - 2.79 mmol/l, ionized calcium - 1.64 mmol/l, parathyroid hormone - 191.4 pg/mL. Ultrasound and MSCT scan of the neck showed an increase of the parathyroid glands under the lower poles of both lobes of the thyroid gland. No functionally active parathyroid glands were found on scintigraphy. The patient underwent bilateral neck exploration with identification of all four parathyroid glands and a double parathyroid adenomectomy. According to a histological study, the removed parathyroid glands are represented by adenomas from the dark main cells. Remission of primary hyperparathyroidism was achieved.

Discussion

This clinical report confirms the literature on a decrease in the sensitivity of imaging methods in the diagnosis of double adenomas. A decrease in the effectiveness of intraoperative monitoring of parathyroid hormone with double adenomas was confirmed. In this patient, a double parathyroid adenomectomy was sufficient to achieve remission of hyperparathyroidism.

Conclusion

With double adenomas, a comprehensive assessment of all imaging methods is required. A positive test during intraoperative monitoring of IPTG does not exclude a double adenoma in a patient. It is necessary to perform a bilateral neck exploration with identification of all parathyroid glands.

[Intraoperative measurement of parathyroid hormone in hyperparathyroidism]

Intraoperative parathyroid hormone (IOPTH) determination is based on the short half-life of parathyroid hormone (PTH) and the rapid analytical technology. The IOPTH provides functional information regarding correction of the overproductive state in hyperparathyroidism (HPT) and is superior to macroscopic evaluation of the parathyroid gland (PG) as well as any (intraoperative frozen section) form of histology (so-called biochemical frozen section). In this article the relevance and evaluation of IOPTH is defined for the most important forms of HPT, for primary HPT, renal secondary and tertiary HPT, multiple endocrine neoplasia type 1 (MEN1) and parathyroid carcinoma and clinical scenarios based on the currently available data. It becomes apparent that the additional benefits of IOPTH depend on diverse prerequisites of the specific type of HPT, the diagnostics as well as individual patient factors and strategic considerations for resection. Overall, the costs for IOPTH are comparably low and seem to be justified with respect to the gain in quality. In the hands of specialized endocrine surgeons IOPTH is an essential tool for intraoperative decision-making and quality assurance.

Multiglandular Parathyroid Disease: the Results of Surgical Treatment

Background. Sporadic multiple gland disease in primary hyperparathyroidism occurs in 7 to 33 % of cases. The absence of specific risk factors, low sensitivity of imaging methods, and low efficiency of bilateral neck exploration and intraoperative monitoring of parathyroid hormone indicate the complexity of the diagnosis and treatment of this disease’s form. Aim of the research. To analyze the results of surgical treatment of multiple lesions of the parathyroid gland in primary and secondary hyperparathyroidism. Methods. There was retrospective study, which included 100 observations of surgical treatment for primary and secondary hyperparathyroidism in the thoracic department of Irkutsk Regional Clinical Hospital from May 2018 to September 2019. The main point was to identify the frequency of surgical treatment outcomes in patients with multiple parathyroid lesions. As part of the study, potential predictors of multiple gland disease in primary hyperparathyroidism were analyzed. Results. Multiple gland disease in primary hyperparathyroidism occurs in 29 % of cases and causes persistence of the disease (p ≤ 0.01). Signs of multiple gland disease in primary hyperparathyroidism include the level of ionized calcium, parathyroid hormone (p ≤ 0.05), creatinine level and glomerular filtration rate (p ≤ 0.01). A negative result of intraoperative monitoring correlates with persistence of primary hyperparathyroidism in multiple lesions (χ2, p ≤ 0.05). Selective parathyroidectomy is associated with persistence of hyperparathyroidism in multiple lesions (χ2, p ≤ 0.05), while total parathyroidectomy is associated with remission of the disease (χ2, p ≤ 0.05). We did not find a statistically significant relationship between the results of surgical treatment for morphology of the parathyroid glands (χ2, p > 0.1). Conclusion. Multiple gland disease is the main cause of persistence of primary hyperparathyroidism. This form of the disease corresponds to lower levels of calcium, parathyroid hormone, and kidney function. Persistence factors have been established: removal of less than four parathyroid glands and a negative result of intraoperative monitoring of parathyroid hormone. Bilateral neck exploration does not reduce the incidence of disease persistence.

Application of transoral endoscopic parathyroidectomy via vestibular approach, endoscopic parathyroidectomy via areola approach for parathyroid adenoma

BACKGROUND

Transoral endoscopic parathyroidectomy via vestibular approach (TOEPVA) and total endoscopic parathyroidectomy via areola approach (EPA) are commonly used endoscopic parathyroidectomy approaches. This study compares effectiveness of these approaches with conventional open parathyroidectomy (COP) in relation to safety, associated trauma, and feasibility in the treatment of parathyroid adenoma (PTA).

METHODS

We examined patients who had undergone TOEPVA (n = 15), EPA (n = 14), and COP (n = 30). All patients had a pathological diagnosis of PTA. We analyzed operative time, intraoperative blood loss, postoperative visual analog scale (VAS) score, postoperative drainage volume, hospital stay and complications such as changes in parathyroid hormone (PTH) and serum calcium before and after surgery.

RESULTS

Clinical variables across the three experimental groups were similar except for patient age. TOEPVA and EPA groups had a higher proportion of young patients than COP group. Operation time for endoscopic group was longer than that of open group, and the longest operation time was recorded in TOEPVA group (P = 0.000). Postoperative VAS score: postoperative pain in patients in the endoscopic group was less than that of patients in the open group on the first day (P = 0.001). Postoperative pain in patients of the endoscopic group was significant on the second day (P = 0.044). Pain experienced by patients in the three groups was the same on the third day after surgery (P = 0.312). Postoperative drainage volume in the endoscopic group was more than that in the open group (P = 0.000). There were no significant differences between intraoperative blood loss (P = 0.089), complications (P = 0.407) and hospital stay (P = 0.389) in TOEPVA, EPA and COP groups. PTH and serum calcium levels in the three experimental groups were considerably lower after surgery (P < 0.05). Tumor recurrence was not recorded in the three groups during a follow-up period of between 3 and 36 months.

CONCLUSIONS

TOEPVA and EPA are safe treatment options for PTA. The therapeutic effects of TOEPVA and EPA were similar to those of COP in the treatment of PTA.

Evaluation of an optimal cutoff of parathyroid venous sampling gradient for localizing primary hyperparathyroidism

INTRODUCTION

Parathyroid venous sampling (PVS) has been reported to be a useful adjunctive test in localizing lesions in elusive cases of primary hyperparathyroidism (PHPT). Conventional cutoff (twofold) is now widely being used, but optimal cutoff threshold for PVS gradient based on discriminatory performance remains unclear.

MATERIALS AND METHODS

Among a total of 197 consecutive patients (mean age 58.2 years, female 74.6%) with PHPT who underwent parathyroidectomy at a tertiary center between 2012 and 2018, we retrospectively analyzed 59 subjects who underwent PVS for persistent or recurrent disease after previous parathyroidectomy, or for equivocal or negative results from conventional imaging modalities including ultrasonography (US) and Tc^99m-Sestamibi SPECT-CT (MIBI). True parathyroid lesions were confirmed by combination of surgical, pathological findings, and intraoperative parathyroid hormone (PTH) changes. Optimal PVS cutoff were determined by receiver-operating characteristics (ROC) analysis with Youden and Liu method.

RESULTS

Compared to subjects who did not require PVS, PVS group tends to have lower PTH (119.8 pg/mL vs 133.7 pg/mL, p = 0.075). A total of 79 culprit parathyroid lesions (left 40; right 39) from 59 patients (left 24; right 26; bilateral 9) were confirmed by surgery. The optimal cutoff for PVS gradient was estimated as 1.5-fold gradient (1.5 ×) with sensitivity of 61.8% and specificity of 84%. When 1.5 × cutoff was applied, PVS improved the discrimination for true parathyroid lesions substantially based on area under ROC (0.892 to 0.942, p < 0.001) when added to US and MIBI.

CONCLUSION

Our findings suggest that PVS with cutoff threshold 1.5 × can provide useful complementary information for pre-operative localization in selected cases.

A clinical perspective of parathyroid hormone related hypercalcaemia

There are many causes of hypercalcaemia including hyperparathyroidism, drugs, granulomatous disorders and malignancy. Parathyroid hormone (PTH) related hypercalcaemia is most commonly caused by primary hyperparathyroidism (PHPT) and more rarely by familial hypocalciuric hypercalcaemia (FHH). Algorithms for diagnosis of PTH related hypercalcaemia require assessment of a 24-h urinary calcium and creatinine excretion to calculate calcium/creatinine clearance ratio and radiological investigations including ultrasound scan and ^99mTc-sestamibi-SPECT/CT. To illustrate investigations and management of parathyroid-related hypercalcaemia, we present a selection of distinct cases of PHPT due to eutopic and ectopic parathyroid adenomas, as well as a case with a syndromic form of PHPT (multiple endocrine neoplasia type 1), and a case with FHH type 1 due to a CASR inactivating mutation. Additional cases with normocalcaemic hyperparathyroidism and secondary hyperparathyroidism are included for completeness of differential diagnosis. The common eutopic parathyroid adenomas are easily treated with parathyroidectomy while the less common ectopic parathyroid adenomas require more complex investigations and operative procedures such as video-assisted thoracoscopic surgery. On the other hand, the much less common FHH does not require treatment. Assessment of kin with FHH is important to identify members with this inherited condition in order to prevent unnecessary interventions.

Postoperative Horner's syndrome following excision of incidental cervical ganglioneuroma during hemithyroidectomy and parathyroid gland exploration

This 49-year-old woman was referred to ear, nose and throat (ENT) with primary hyperparathyroidism. Imaging studies failed to localise the adenoma so she required four-gland parathyroid exploration. She also required diagnostic left hemithyroidectomy as she had a U3 nodule with multiple insufficient fine needle aspirations (FNAs). Intraoperatively, the left thyroidectomy proceeded uneventfully. No convincing left inferior parathyroid gland was identified however palpation revealed a 1 cm mass just medial to carotid artery. This was excised as probable ectopic parathyroid gland. She was discharged two days later. Thirteen days postoperatively she attended Eye Casualty with a left-sided Horner's syndrome. A CT angio of aortic arch was normal. She was reviewed at ENT outpatients. Histopathology report of the expected ectopic parathyroid gland returned as benign ganglioneuroma, likely arising from her left sympathetic chain. Horner's syndrome is a common side effect from excision of ganglioneuromas, but an incredibly rare side effect from thyroid or parathyroid surgery.

The role of intraoperative parathyroid hormone (IOPTH) determination for identification and surgical strategy of sporadic multiglandular disease in primary hyperparathyroidism (pHPT)

Intraoperative PTH monitoring (IOPTH) made minimally invasive parathyroidectomy in patients with primary HPT possible. However, with the increasing accuracy of preoperative localization studies there is a growing discussion if IOPTH is necessary in patients with localized single gland disease (concordant preoperative localization studies). Different interpretation criteria have been developed - each with their particular advantages and disadvantages, but the "perfect" criterion is still missing. Despite several pitfalls, which can be recognized intraoperatively and do not necessarily lead to a more extensive surgery, IOPTH seems to be a useful adjunct in surgery for PHPT. However, according to current guidelines, selected patients may be operated without IOPTH but need to be informed about the possibly increased risk of recurrent disease.

Three Patients with Lithium-Associated Hyperparathyroidism: Literature Review Regarding Medical and Surgical Management

Lithium (Li) carbonate has been established as a mood stabilizer and an efficacious treatment for bipolar disorder since its discovery by Dr. John Cade in 1948. Li interacts significantly with organ systems and endocrine pathways. One of the most challenging side effects of Li to manage is its effect on the parathyroid glands. Dysregulation of parathyroid signaling due to Li results in hypercalcemia due to increased vitamin D₃ generation, increased calcium absorption from the gut, and bone resorption, occasionally resulting in concomitant hypercalciuria. However, hypercalciuria is not a definitive feature for hyperparathyroidism, and normal calcium excretion might be seen in these patients. Hypercalcemia may also result from volume contraction and decreased renal clearance, which are commonly seen in these patients. Anatomically the parathyroid abnormalities can present as single or multiglandular disease. We report 3 cases where the patients developed multiple side effects of Li therapy as well as hypercalcemia due to hyperparathyroidism. The literature is reviewed with regard to medical and surgical management of Li-associated hyperparathyroidism in the context of these 3 presented cases.

Characterization of Calcium Homeostasis in Lithium-Treated Patients Reveals Both Hypercalcaemia and Hypocalcaemia

INTRODUCTION

Prevalence studies demonstrate that a significant proportion of lithium-treated patients develop hypercalcaemia (3-30%). Lithium-associated hyperparathyroidism (LHPT) is poorly defined, and calcium homeostasis may be affected in a more complicated fashion than purely by elevated PTH secretion. The current study aims to examine in detail calcium homeostasis principally with regard to lithium duration.

METHODS

Medical records of 297 lithium-treated patients (193 women, 104 men; median age 58 years) were examined, and information on gender, age, lithium treatment duration and calcium homeostasis was obtained. The median treatment duration with lithium was 16 (1.5-45) years.

RESULTS

A total of 8504 calcium values were retrieved. Before initiation of lithium treatment, serum calcium was on average 2.33 mmol/l (2.02-2.60). During the treatment period, 178 patients (60%) remained normocalcaemic, 102 (34%) developed hypercalcaemia or were strongly suspected of LHPT, 17 (6%) had 3 or more intermittent episodes of hypocalcaemia. Forty-one per cent of patients with suspected or confirmed LHPT had low (<4 mmol) 24-h urine calcium levels. The success rate after 33 parathyroidectomies was 35%, hyperplasia being diagnosed in 75% of extirpated glands.

CONCLUSIONS

The prevalence of hypercalcaemia during lithium treatment is very high. In addition, hypocalcaemic episodes appear to occur frequently, possibly reflecting a more complicated parathyroid dysfunction than previously known. Long-term surgical results are unsatisfactory. LHPT biochemical profile is different from that of primary hyperparathyroidism and is in some ways similar to familial hypocalciuric hypercalcaemia.

Surgical treatment in patients with single and multiple gland primary hyperparathyroidism with the use of intraoperative parathyroid hormone monitoring: extensive single-center experience

PURPOSE

To evaluate a single-center extensive experience and effectiveness in surgical treatment of primary hyperparathyroidism (pHPT) with the use of rapid intraoperative parathyroid hormone (ioPTH) monitoring in patients with single gland (SGpH) or multiple gland (MGpH) disease.

METHODS

This retrospective, single-center cohort study included 214 patients with pHPT treated from January 2010 to June 2017. In total, 172 patients fulfilled the inclusion criteria having at least one preoperative localization image study and measurement of ioPTH. Statistical analysis was made by the chi-square test and Student's t tests.

RESULTS

Of the 172 patients, 146 were women (85%) and 26 men (15%), with a mean age of 56.9 years; 153 (89%) had SGpH and 19 (11%) MGpH. The mean follow-up was 41.8 months. A total of 153 surgical procedures were performed as minimal invasive parathyroidectomy (MIP) based on a SGpH diagnosis; operative success was achieved in 150 cases (98%), according to ioPTH concentrations. The remainder (19 procedures) were performed as bilateral neck exploration (BNE) based on a MGpH diagnosis; operative success was achieved in 16 cases (84%). ioPTH correctly modified the initially planned operation in 26.3% of patients with MGpH.

CONCLUSIONS

ioPTH enables the surgical treatment of patients with pHPT with focused approaches and excellent results, as it helps the surgeon to identify cases of MGpH. ioPTH adds value to cases where preoperative imaging failed to detect the affected gland or the results are inconclusive. According to the literature, its application seems to be of marginal benefit in cases in which there are two concordant preoperative imaging studies.

Surgical Treatment of Primary Hyperparathyroidism: Which Therapy to Whom?

Primary hyperparathyroidism (pHPT) is characterized by an increase in the levels of PTH and Ca, or one of these (Ca, PTH) as a result of a dysregulation of calcium (Ca) metabolism due to inappropriate excess parathyroid hormone (PTH) autonomously produced from one or more than one parathyroid glands. Ninety to 95% of pHPT is a sporadic type, which is not associated with the familial history and other endocrine organ tumors, and 5-10% of it is hereditary. While 80-85% of pHPT arises from a single parathyroid adenoma, 4-5% is caused by a double adenoma, 10-15% by multigland hyperplasia and less than 1% by parathyroid cancer. The diagnosis of pHPT is reached biochemically. The only curative treatment of pHPT is surgery. The choice of surgery in pHPT may vary depending on whether the patient has hereditary HPT or thyroid disease requiring surgical treatment, preoperative localization studies and the findings in these studies, the possibilities of using intraoperative PTH and the preference of the surgeon. The preoperatively determined surgical strategy can be revised according to intraoperative findings in case of need to achieve excellent results. The two main approaches in the surgical treatment of pHPT are BNE (bilateral neck exploration) and MIP (minimal invasive parathyroidectomy). Although BNE is a consistently valid option that has excellent results in the surgical treatment of pHPT and is considered the gold standard, MIP is the ideal approach in selected patients with clinically and radiologically considered a single-gland disease. Negative imaging is not a contraindication for parathyroid surgery and is not a criterion for the presence or absence of surgical indication. Although both methods are safe and effective in the surgical treatment of sporadic pHPT, there is still controversy regarding the effectiveness of both methods. Surgical intervention should establish the risk-benefit balance well, minimize the risk of persistent and recurrent disease and provide the highest cure rate without increasing the risk of complications. Complication rates are higher in the secondary surgery, thus in secondary procedures, selective surgery should be performed under guidance of an imaging modality. The surgical strategy should be determined to achieve maximum cure with minimum dissection and minimal morbidity. In this study, we aimed to determine the type of surgical treatment and pHPT patients suitable for the surgical treatment.

Can Met-PET/CT Predict Sporadic Multiglandular Hyperparathyroidism? Report of a Case and Review of the Literature

Background

Primary hyperparathyroidism (pHPT) is a common endocrine disorder of the parathyroid glands. In most cases pHPT is caused by single gland disease, but about 10% of patients suffer from sporadic multiglandular disease (MGD). Patients with MGD, especially with ectopic parathyroid adenomas, have an increased risk for persistence/recurrence after surgery. Normally, sporadic MGD cannot be diagnosed preoperatively by parathyroid scintigraphy. We analyzed the potential of positron emission tomography/computed tomography (Met-PET/CT) to predict MGD.

Methods and Case Presentation

We reviewed the literature, if preoperative Met-PET/CT could predict MGD in patients with pHPT. Further, we present a 71-year-old female with ectopic MGD. Preoperative localization via Met-PET/CT showed MGD with two areas suspected to be enlarged parathyroid glands (left lateral to the thyroid lobe and posterior mediastinum). Both diagnostic findings were extirpated and parathormone dropped into normal levels.

Results

We identified four additional manuscripts, referring to MGD and Met-PET/CT with divergent results. Preoperative localization diagnostics using Met-PET/CT may not necessarily identify MGD. In most cases, Met-PET/CT localized only one adenoma and localizes larger adenomas more reliably than smaller adenomas.

Conclusion

Identifying patients at risk of MGD preoperatively remains challenging. We found MET-PET/CT seems to predict MGD in patients with large size and high weight PTH adenomas. For ectopic parathyroid adenomas, accurate preoperative localization is the key to successful surgical removal. Met-PET/CT appears to have great potential in soft-tissue analysis of complex anatomical regions and can predict ectopic parathyroid adenomas.

Endoscopic transoral parathyroidectomy: Initial experience

BACKGROUND

We evaluate our initial experience of transoral vestibular approach parathyroidectomy (TOEPVA) for the treatment of primary hyperparathyroidism.

METHODS

We conducted a prospective study of patients with single parathyroid adenoma, using TOEPVA to perform the parathyroidectomy. The variables we analyzed were size, volume, and location of the adenoma, bleeding, identification, and preservation of the recurrent laryngeal nerve, injury to the mental nerve, and the effective cure rate, using measures of central tendency.

RESULTS

Our study included 21 women, with an average age of 43 years. The recurrent laryngeal nerve and mental nerve suffered no permanent damage, the average size of the adenoma was 26.6 mm, and a volume of 3.95 mL. We were able to identify the adenoma and cure the hyperparathyroidism in 20 of the patients (95.2%).

CONCLUSIONS

TOEPVA is viable and safe in who wish to avoid the cervical scar resulting for the patient with primary hyperparathyroidism.

[Diagnostics and treatment of primary hyperparathyroidism]

Primary hyperparathyroidism is a disease that occurs more frequently than generally thought and is often overlooked. Classical symptoms are bone pain and osteoporosis, renal calculi and peptic ulcers. Many patients are asymptomatic or have unspecific complaints. It is easy to establish the biochemical diagnosis based on calcium and parathormone (PTH) levels and 24-h urine calcium excretion. The most sensitive localization procedures for parathyroid adenomas are sonography and Tc-99^m-MIBI scintigraphy. The indication for surgery is undisputed in symptomatic patients; however, there is controversy concerning patients without classical symptoms. Operative therapy is highly successful. Focused operative procedures are currently available besides the traditional 4‑gland exploration. When focused techniques are used, the operative success should be confirmed by intraoperative determination of the parathormone level.

Mild sporadic primary hyperparathyroidism: high rate of multiglandular disease is associated with lower surgical cure rate

BACKGROUND

Mild primary hyperparathyroidism (serum calcium ≤ 2.85 mmol/L) is the most representative form of pHPT nowadays. The aim of this study was to evaluate its subtypes and the multiglandular disease (MGD) rate as it may lower the sensitivity of preoperative parathyroid scintigraphy and the surgical cure rate.

METHODS

We retrospectively included patients with mild pHPT who underwent parathyroid dual-tracer scintigraphy with ^99mTc-MIBI SPECT/CT and surgery between January 2013 and December 2015. Cure was defined as normalization of serum calcium (or PTH in the normocalcemic form) at 6 months. MGD was defined by either two abnormal resected glands or persistent disease after resection of at least one abnormal gland.

RESULTS

We included 121 patients. Median preoperative serum calcium was 2.68 mmol/L and median PTH was 83.4 pg/mL. A total of 141 glands were resected (95 adenomas, 33 hyperplasias). The subtypes were 57% classic, 32.2% normohormonal, and 10.7% normocalcemic. MGD occurred in 23.5% of patients divided as 13%, 30%, and 64% respectively (p = 0.0011). The surgical cure rate was 85.2%. The normocalcemic form had lower cure rate than the normohormonal (45% vs 84%, p = 0.018) and classic forms (45% vs 93%, p = 0.0006). MIBI scintigraphy identified at least one abnormal lesion, later confirmed by the pathologist in 90/98 patients, making the sensitivity per patient 91.8% (95% CI 84.1-96.2%).

CONCLUSIONS

MGD is strongly associated with mild pHPT, especially the normocalcemic form where it accounts for 64% of cases. Bilateral neck exploration should be performed in this population to improve the cure rate, even if the scintigraphy shows a single focus.

The surgical management of sporadic primary hyperparathyroidism

Sporadic primary hyperparathyroidism (pHPT) is the commonest cause of hypercalcaemia in the ambulatory population. It has a female preponderance and its incidence is increasing. In 85% of cases it is caused by a single parathyroid adenoma, with four gland hyperplasia in up to 20%. Parathyroidectomy is the only cure and bilateral neck exploration remains the gold standard to achieve this. Several adjuncts have been developed to improve success rates or limit the extent of surgery. Pre-operative localisation permits planned targeted surgery. Ultrasound scanning and scintigraphy are the most commonly employed, although 4DCT has become a useful modality in complex cases. However, excellent rates of biochemical cure can be achieved in specialist centres when pre-operative imaging is negative. Pre-operative prediction models and intra-operative parathyroid hormone (ioPTH) assist, with high sensitivity, to predict single gland disease. Reoperations present a major challenge to the endocrine surgeon.

Lithium-Associated Hypercalcemia: Pathophysiology, Prevalence, Management

BACKGROUND

Lithium-associated hypercalcemia (LAH) is an ill-defined endocrinopathy. The aim of the present study was to determine the prevalence of hypercalcemia in a cohort of bipolar patients (BP) with and without concomitant lithium treatment and to study surgical outcomes for lithium-associated hyperparathyroidism.

METHODS

Retrospective data, including laboratory results, surgical outcomes and medications, were collected from 313 BP treated with lithium from two psychiatric outpatient units in central Sweden. In addition, data were collected from 148 BP without lithium and a randomly selected control population of 102 individuals. Logistic regression was used to compare odds of hypercalcemia in these respective populations.

RESULTS

The prevalence of lithium-associated hypercalcemia was 26%. Mild hypercalcemia was detected in 87 out of 563 study participants. The odds of hypercalcemia were significantly higher in BP with lithium treatment compared with BP unexposed to lithium (adjusted OR 13.45; 95% CI 3.09, 58.55; p = 0.001). No significant difference was detected between BP without lithium and control population (adjusted OR 2.40; 95% CI 0.38, 15.41; p = 0.355). Seven BP with lithium underwent surgery where an average of two parathyroid glands was removed. Parathyroid hyperplasia was present in four patients (57%) at the initial operation. One patient had persistent disease after the initial operation, and six patients had recurrent disease at follow-up time which was on average 10 years.

CONCLUSION

The high prevalence of LAH justifies the regular monitoring of calcium homeostasis, particularly in high-risk groups. If surgery is necessary, bilateral neck exploration should be considered in patients on chronic lithium treatment. Prospective studies are needed.

Is Unilateral Neck Surgery Feasible in Patients with Sporadic Primary Hyperparathyroidism and Double Negative Localisation?

INTRODUCTION

Ultrasound and Tc99mMIBI scans are used to localise parathyroid tumours in sporadic primary hyperparathyroidism (pHPT). Intra-operative PTH (ioPTH) assay facilitates unilateral neck exploration (UNE). When both ultrasound and MIBI are negative, it is our policy to explore the left side of the neck and only proceed to bilateral neck exploration (BNE) when either a tumour is not found or when ioPTH does not fall to >50% of the highest pre-excision value. The aim of this study was to investigate the outcome of our approach to 'double negative' patients.

METHODS

A retrospective analysis of patients undergoing primary parathyroidectomy for pHPT. Data were obtained from a prospective surgical database and the hospital electronic patient record.

RESULTS

Between January 2004 and November 2014, 746 patients underwent a parathyroidectomy for pHPT. Those who did not have both pre-operative scans, ioPTH or a minimum of 6-month follow-up were excluded. Of 552 patients, 111 (20%) had double negative scans (group A), and in 441, either one or both scans were positive (group B). Median age was 61.5 years (range 10-88). Pre-operative PTH level was significantly lower in group A: 11.8 pmol/l (range 3.1-38.8) versus 14.9 pmol/l (range 2.8-101.6; P < 0.01). Median tumour weight was significantly lower in group A: 280 mg (range 50-3710) versus 573 mg (range 10-12,000; P < 0.01). Overall rate of multiple gland disease (MGD) was 11%; 24% in group A and 7% in group B (P < 0.01). Overall rate of UNE in Group A was 28% and converse to the rate in Group B (76%; P < 0.01). Sensitivity and specificity of ioPTH to detect MGD were 98 and 98% in Group A versus 98 and 100% in Group B. First-time cure rate was 92.7% in group A and 96.8% in group B (P < 0.05).

CONCLUSION

A double negative scan is associated with small tumours and higher rates of MGD. Despite these challenges, surgery is successful in this group of patients reinforcing the message that negative localisation is not a contraindication for parathyroidectomy. We demonstrated that it is feasible to offer unilateral neck surgery to 28% of patients with double negative scans. A randomised trial is needed to compare BNE with ioPTH/UNE in this select population.

Niche point-of-care endocrine testing - Reviews of intraoperative parathyroid hormone and cortisol monitoring

Point-of-care (POC) testing, which provides quick test results in near-patient settings with easy-to-use devices, has grown continually in recent decades. Among near-patient and on-site tests, rapid intraoperative and intra-procedural assays are used to quickly deliver critical information and thereby improve patient outcomes. Rapid intraoperative parathyroid hormone (ioPTH) monitoring measures postoperative reduction of parathyroid hormone (PTH) to predict surgical outcome in patients with primary hyperparathyroidism, and therefore contributes to the change of parathyroidectomy to a minimally invasive procedure. In this review, recent progress in applying ioPTH monitoring to patients with secondary and tertiary hyperparathyroidism and other testing areas is discussed. In-suite cortisol monitoring facilitates the use of adrenal vein sampling (AVS) for the differential diagnosis of primary aldosteronism and adrenocorticotropic hormone (ACTH)-independent Cushing syndrome. In clinical and psychological research settings, POC testing is also useful for rapidly assessing cortisol in plasma and saliva samples as a biomarker of stress. Careful resource utilization and coordination among stakeholders help to determine the best approach for implementing cost-effective POC testing. Technical advances in integrating appropriate biosensors with microfluidics-based devices hold promise for future real-time POC cortisol monitoring.