Persistently Elevated PTH After Parathyroidectomy at One Year: Experience in a Tertiary Referral Center

Radiofrequency Ablation of Parathyroid Adenoma: Results of a Retrospective Analysis of 60 Patients

PURPOSE

To present the effectiveness and safety of radiofrequency ablation (RFA) in parathyroid adenoma (PTA).

MATERIALS AND METHODS

In this retrospective study, 60 patients with a single PTA were evaluated for changes in biochemical and ultrasonographic features up to 6 months after RFA of the lesion. Adenomas were ablated with an alternative technique so called "Nik jet dissection" which incorporates full hydrodissection and polar artery coagulation. Complications as well as the variations in biochemical data and nodule volumes were analyzed between baseline measurements and at each follow-up interval data (first day, 1, 3, and 6 months after ablation) were analyzed.

RESULTS

A significant reduction in serum intact parathyroid hormone and calcium levels was observed 6 months after ablation, with a mean difference of - 83.4 ± 104.1 pg/mL, p < 0.001, and - 0.29 ± 0.22 mmol/L, p < 0.001, respectively. Serum phosphorus levels increased significantly with a mean difference of 0.09 ± 0.19 mmol/L, p = 0.040 at the end of the follow up. We observed a significant volume reduction rate of parathyroid adenomas with 89 ± 20.8 percent, p < 0.001. Also, 51% of adenomas disappeared at the end of the follow up. In this study, two cases of hematoma and one case of transient hoarseness (grade 1 of the CIRSE classification) were encountered.

CONCLUSION

Our study showed that RFA with the alternative technique, called "Nik jet dissection" is a safe and effective modality in management of PTA. Therefore, we suggest expanding the indications for RFA in PTA management, especially when surgery is not feasible.

LEVEL OF EVIDENCE

Level 3, Local non-random sample.

Microwave ablation for recurrent primary hyperparathyroidism in four patients with multiple endocrine neoplasia type 1: a case series report

Multiple endocrine neoplasia type 1 (MEN1), a rare tumor syndrome, is inherited in an autosomal dominant pattern, mainly manifested as primary hyperparathyroidism (PHPT). Surgery is preferred for patients with MEN1 and PHPT. Thermal ablation has been widely applied for PHPT but rarely for postoperative recurrent PHPT in MEN1 patients. Based on a series of cases, we aimed to investigate the clinical efficacy and safety of ultrasound-guided percutaneous microwave ablation in the treatment of MEN1 patients with postoperative recurrence of PHPT.

Normocalcemic hyperparathyroidism after successful parathyroidectomy for single parathyroid adenoma: Prevalence, etiological factors, predictive markers, treatment and evolution

BACKGROUND AND OBJECTIVE

Postparathyroidectomy normocalcemic hyperparathyroidism (PPNCHPPT) is a frequent situation for which we have no information in our country. The objective is to know our prevalence of PPNCHPPT, the associated etiological factors, the predictive markers, the treatment administered and the evolution.

PATIENTS AND METHOD

Retrospective observational cross-sectional study on 42 patients. Twelve patients with PPNCHPPT and 30 without PPNCHPPT are compared.

RESULTS

HPPTNCPP prevalence: 28.6%. Etiological factors: vitamin D deficiency: 75%; bone remineralization: 16.7%; renal failure: 16.7%; hypercalciruria: 8.3%. No change in the set point of calcium-mediated parathormone (PTH) secretion was observed, but an increase in the preoperative PTH/albumin-corrected calcium (ACC) ratio was observed. Predictive markers: PTH/ACC ratio (AUC 0.947; sensitivity 100%, specificity 78.9%) and PTH (AUC 0.914; sensitivity 100%, specificity 73.7%) one week postparathyroidectomy.

EVOLUTION

follow-up 30 ± 16.3 months: 50% normalized PTH and 8.3% had recurrence of hyperparathyroidism. Patients with PPNCHPPT less frequently received preoperative treatment with bisphosphonates and postoperative treatment with calcium salts.

CONCLUSIONS

This is the first study in our country that demonstrates a mean prevalence of PPNCHPPT, mainly related to a vitamin D deficiency and a probable resistance to the action of PTH, which can be predicted by the PTH/ACC ratio and PTH a week post-intervention and often evolves normalizing the PTH. We disagree with the etiological effect of hypercalciuria and the change in the PTH/calcemia regulation set point, and we acknowledge the scant treatment administered with calcium salts in the postoperative period.

Efficacy and safety of radiofrequency ablation for primary and secondary hyperparathyroidism: a retrospective study

There is now growing interest in the use of Ultrasound-guided radiofrequency ablation (RFA) to treat hyperparathyroidism. But the efficacy and limitations of this treatment have not been described in sufficient detail. Assessing and contrasting the effectiveness and safety of RFA in treating primary hyperparathyroidism (PHPT) and secondary hyperparathyroidism (SHPT). This retrospective study included 57 HPT patients (48 for PHPT and 9 for SHPT) who underwent RFA between January 2017 and April 2021. The serum intact parathyroid hormone (iPTH) and calcium, hyperplastic parathyroid volume, volume reduction rate (VRR) before and after RFA, clinical success rate, symptoms, and complications were analyzed and compared. In SHPT group, bone pain (7/9, 77.8%), skin pruritus (4/9, 44.4%), and multiple hyperplastic parathyroid glands (4/9, 44.4%) were more common compared to the PHPT group. After 12 months of follow-up, the serum iPTH, calcium, and the volume of PHPT and SHPT groups had decreased by more than 60%, 10%, and 90%, respectively (P < 0.05). In the VRR, 13 glands of SHPT (72.2%) and 42 glands of PHPT (87.5%) had achieved the clinical success. In addition, the preoperative and postoperative serum iPTH were higher in the SHPT group than in the PHPT group (P < 0.05). In terms of the serum iPTH and calcium, the PHPT group had substantially higher rates of clinical success, with 42 patients (87.5%) and 46 patients (95.8%) meeting the criteria, respectively compared to 3 patients (33.3%) and 6 patients (66.7%) of SHPT group (P < 0.05). After RFA, the clinical symptoms improved in both groups. The overall incidence of complications (hoarseness and postoperative hematoma) of RFA in the two groups was 10.5% (6/57), and hoarseness (3/9, 33.3%) of SHPT group was more common than PHPT group. All the complications were resolved spontaneously within 12 months after symptomatic treatments. In the treatment of PHPT and SHPT, ultrasound-guided RFA is both successful and safe. PHPT patients have better results in restoring normal iPTH by RFA, and have no considerable difference with the SHPT patients in terms of serum calcium, the volume of the ablation area, and the VRR.

Persistence and Recurrence of Hypercalcemia After Parathyroidectomy Over 5 Decades (1965-2010) in a Community-based Cohort

BACKGROUND

There is limited long-term follow-up of patients undergoing parathyroidectomy. Recurrence is described as 4% to 10%. This study evaluated persistence and recurrence of hypercalcemia in primary hyperparathyroidism after parathyroidectomy.

METHODS

Single-institution retrospective (1965-2010) population-based cohort from Olmsted County (MN) of patients undergoing surgery for primary hyperparathyroidism. Patients' demographic data, preoperative and postoperative laboratory values, clinical characteristics, surgical treatment, and follow-up were noted.

RESULTS

A total of 345 patients were identified, 75.7% female, and median age 58.4 years [interquartile range (IQR): 17.6]. In all, 68% of patients were asymptomatic and the most common symptoms were musculoskeletal complaints (28.4%) and nephrolithiasis (25.6%). Preoperative median serum calcium was 11 mg/dL (IQR: 10.8-11.4 mg/dL), and median parathyroid hormone was 90 pg/mL (IQR: 61-169 pg/dL). Bilateral cervical exploration was performed in 38% and single gland resection in 79% of cases. Median postoperative serum calcium was 9.2 mg/dL (IQR: 5.5-11.3). Nine percent of patients presented persistence of hypercalcemia, and recurrence was found in 14% of patients. Highest postoperative median serum calcium was 10 mg/dL (IQR: 6-12.4), and median number of postoperative calcium measurements was 10 (IQR: 0-102). Postoperative hypercalcemia was identified in 37% of patient. Fifty-three percent were attributed to secondary causes, most commonly medications, 22%. Three percent of patients required treatment for postoperative hypercalcemia. Median time to recurrence and death were 12.2 and 16.7 years, respectively.

CONCLUSION

Recurrent hypercalcemia after successful parathyroidectomy is higher than previously reported. Most cases are transient and often associated to other factors with only the minority requiring treatment. Long-term follow-up of serum calcium should be considered in patients after successful parathyroidectomy.

The Eucalcemic Patient With Elevated Parathyroid Hormone Levels

Primary hyperparathyroidism (PHPT) is classically characterized by hypercalcemia with elevated or inappropriately normal parathyroid hormone (PTH) levels. Elevated PTH levels in the presence of normal calcium levels are not infrequently found during the evaluation of metabolic bone disorders or kidney stone disease. This can be caused by secondary hyperparathyroidism (SHPT) or normocalcemic primary hyperparathyroidism (NPHPT). NPHPT is due to autonomous parathyroid function whereas SHPT is caused by a physiologic stimulation to PTH secretion. Many medical conditions and medications can contribute to SHPT, and differentiation between SHPT and NPHPT may be difficult. Cases are presented to illustrate examples. In this paper, we review the distinction between SHPT and NPHPT as well as end organ effects of NPHPT and outcomes of surgery in NPHPT. We suggest that the diagnosis of NPHPT be made only after careful exclusion of causes of SHPT and consideration of medications that can increase PTH secretion. Further, we advise a conservative approach to surgery in NPHPT.

A rare case of "Brown tumor" of the axis with parathyroid adenoma and tertiary hyperparathyroidism

"Brown tumors (BTs)" of the spine are benign rare lesions, seen in about 5%-13% of all patients with chronic hyperparathyroidism (HPT). They are not true neoplasms and are also known as osteitis fibrosa cystica or occasionally osteoclastoma. Radiological presentations are often misleading and may mimic other common lesions such as metastasis. A strong clinical suspicion is therefore necessary, especially in the background of chronic kidney disease with HPT and parathyroid adenoma. Surgical spinal fixation in case of instability due to pathological fracture may be required along with excision of the parathyroid adenoma being the treatment of choice, that maybe usually curative and carries a good prognosis. We would like to report one such rare case of BT involving the axis, or C2 vertebra, presenting with neck pain and weakness that was treated surgically. Only a few cases of spinal BTs have been reported so far in the literature. Involvement of cervical vertebrae and in particular C2 is rarer still with the one in this report only being the fourth such case.

The Efficacy and Safety of Medical and Surgical Therapy in Patients With Primary Hyperparathyroidism: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Both medical and surgical therapy represent potential management options for patients with asymptomatic primary hyperparathyroidism (PHPT). Because uncertainty remains regarding both medical and surgical therapy, this systematic review addresses the efficacy and safety of medical therapy in asymptomatic patients or symptomatic patients who decline surgery and surgery in asymptomatic patients. We searched Medline, Embase, Cochrane Central Register of Controlled Trials, and PubMed from inception to December 2020, and included randomized controlled trials in patients with PHPT that compared nonsurgical management with medical therapy versus without medical therapy and surgery versus no surgery in patients with asymptomatic PHPT. For surgical complications we included observational studies. Paired reviewers addressed eligibility, assessed risk of bias, and abstracted data for patient-important outcomes. We conducted random-effects meta-analyses to pool relative risks and mean differences with 95% confidence intervals and used Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) to assess quality of evidence for each outcome. For medical therapy, 11 trials reported in 12 publications including 438 patients proved eligible: three addressed alendronate, one denosumab, three cinacalcet, two vitamin D, and two estrogen therapy. Alendronate, denosumab, vitamin D, and estrogen therapy all increased bone density. Cinacalcet probably reduced serum calcium and parathyroid hormone (PTH) levels. Cinacalcet and vitamin D may have a small or no increase in overall adverse events. Very-low-quality evidence raised the possibility of an increase in serious adverse events with alendronate and denosumab. The trials also provided low-quality evidence for increased bleeding and mastalgia with estrogen therapy. For surgery, six trials presented in 12 reports including 441 patients proved eligible. Surgery achieved biochemical cure in 96.1% (high quality). We found no convincing evidence supporting an impact of surgery on fracture, quality of life, occurrence of kidney stones, and renal function, but the evidence proved low or very low quality. Surgery was associated with an increase in bone mineral density. For patients with symptomatic and asymptomatic PHPT, who are not candidates for parathyroid surgery, cinacalcet probably reduced serum calcium and PTH levels; anti-resorptives increased bone density. For patients with asymptomatic PHPT, surgery usually achieves biochemical cure. These results can help to inform patients and clinicians regarding use of medical therapy and surgery in PHPT. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Ultrasound-guided microwave and radiofrequency ablation for primary hyperparathyroidism: a prospective, multicenter study

OBJECTIVES

To prospectively investigate the efficacy and safety of ultrasound (US)-guided microwave ablation (MWA) and radiofrequency ablation (RFA) for primary hyperparathyroidism (PHPT).

METHODS

We performed a prospective multicenter study of MWA and RFA for PHPT between August 2017 and October 2020 at five centers. Laboratory testing was performed pre- and post-ablation and followed for at least 6 months. The primary outcome was the cure rate. Secondary outcomes were complications and dynamic changes in serum levels of PTH, calcium, phosphorus, and ALP after ablation.

RESULTS

A total of 132 participants (mean age, 57.33 ± 13.90 years), with 141 parathyroid nodules (median maximal diameter, 1.55 cm) undergoing either MWA or RFA, were enrolled in the study. The technique success rate was 99.29% (140/141). The follow-up period was 6-36 months (median, 12 months). The cure rate was 80.30% (106/132). Pre-ablation PTH level was the independent factor associated with cure rate (Odds ratio (OR), 0.22; 95% CI, 0.07-0.69; p = 0.0090). There was no difference in cure rate between the MWA group and the RFA group (80.22% vs. 80.49%, p = 0.971). The only main complication was hoarseness (5.30%).

CONCLUSIONS

US-guided MWA and RFA for PHPT is an effective and safe procedure in the treatment of PHPT. Pre-ablation PTH level is the key factor affecting the cure rate after MWA and RFA.

KEY POINTS

• To our knowledge, this is the first prospective multicenter clinical trial with ultrasound-guided MWA and RFA for primary hyperparathyroidism. • There was no difference in cure rate between the MWA and RFA groups for primary hyperparathyroidism. The overall cure rate was 80.30%. • Pre-ablation PTH level was the independent factor associated with cure rate (odds ratio (OR), 0.22; 95% CI, 0.07-0.69; p = 0.0090).

Evolution of intra-operative parathyroid hormone and its application in parathyroid surgery

The history and evolution of parathyroid hormone is a true testament to inter-disciplinary collaboration among anatomists, biochemists and surgeons. The parathyroid glands were the last endocrine glands to be discovered in the mid-1800s. Over the next century, progress in the evaluation of primary hyperparathyroidism, the identification of parathyroid hormone (PTH) and its application for use in the field of parathyroid surgery have led to a significant improvement in surgical cure rates, accompanied by a shift toward minimally invasive surgical options. This chapter provides a historical lens through which we can view these relatively recent advancements, as well as the current role of parathyroid hormone, both with regards to pre-operative localization and intra-operative detection of abnormal glands. Furthermore, we discuss the importance of parathyroid hormone in the management of complex multiglandular disease and reoperative cases, as well as the significance of persistently elevated PTH levels post-parathyroidectomy.

Predicting ultrasound-guided thermal ablation benefit in primary hyperparathyroidism

OBJECTIVES

Ultrasound (US)-guided thermal ablation for primary hyperparathyroidism (PHPT) is a relatively novel minimally invasive treatment. The recurrence rate after ablation is between 10 and 15%. The characteristics of patients who can benefit from thermal ablation therapy are not clear yet. The aim of this research was to investigate the validity of a parathyroid hormone (PTH)-based classifier for stratifying patients with PHPT.

METHODS

A total of 171 patients were screened, 148 (86.5%) of whom were eligible and were divided into development (n = 104) and external validation (n = 44) cohorts. The potential relationship between the PTH-based classifier and the cure rate of patients was initially assessed in the primary cohort and then validated in the external validation cohort. The nomogram was computed from the logistic regression model.

RESULTS

A cut-off of PTH < 269.1 pg/mL or ≥ 269.1 pg/mL as the optimal prognostic threshold in the training cohort was generated to stratify the patients into low-risk and high-risk groups. Patients with PTH levels < 269.1 pg/mL in the training cohort had a higher cure rate than patients with PTH levels ≥ 269.1 pg/mL (p < 0.001). The PTH level remained the strongest predictor of the cure rate in all cohorts. Furthermore, a nomogram based on the PTH level was developed to predict the cure rate in the training cohort and it performed well in the external validation cohort (AUC: 0.816, 95%CI 0.703 to 0.930; AUC: 0.816, 95%CI 0.677 to 0.956).

CONCLUSIONS

The PTH-based classifier may help with individualised treatment planning for selecting patients who may benefit from thermal ablation.

KEY POINTS

• This is the first analysis of predictors affecting the outcome of US-guided thermal ablation of primary hyperparathyroidism and the findings can be used to identify the potential beneficiary population of thermal ablation of primary hyperparathyroidism. • Parathyroid hormone (PTH) was confirmed as an independent prognostic factor, as it not only showed good accuracy in stratifying patients into high- and low-risk groups in the training and validation cohorts but also outperformed the clinical model. • This study developed and validated a model to predict the treatment success of thermal ablation of primary hyperparathyroidism.

Radiofrequency ablation of parathyroid adenomas causing primary hyperparathyroidism: A report of 27 patients

PURPOSE

To study treatment outcome of parathyroid adenomas using ultrasound-guided radiofrequency ablation.

METHODS

Twenty-seven patients with a single adenoma of the parathyroid gland were included in the study. Using color Doppler ultrasonography, the lesion and its characteristics were determined, and dextrose was injected to dissect the gland from the surrounding structures. The ablation process was done with 6-12 watts of power.

RESULTS

No complications were seen in any of the subjects. A significant reduction was seen in serum parathyroid hormone (PTH) and calcium levels after treatment. PTH levels showed a median decrease of 13.8%, and a median decrease of 8.2% was seen in serum calcium levels (p < 0.001). Phosphorus levels did not change significantly after treatment. In 1-month follow-up of patients, the lesion size had decreased considerably. In long-term follow-up, 11 of 20 patients having subsequent imaging had indistinguishable lesions.

CONCLUSION

Our results showed that RFA of parathyroid adenomas caused a significant reduction in biomedical indicators of disease and resulted in a significant reduction or disappearance of the lesion in the majority of the patients while having no considerable complications.

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.

European Expert Consensus on Practical Management of Specific Aspects of Parathyroid Disorders in Adults and in Pregnancy: Recommendations of the ESE Educational Program of Parathyroid Disorders

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

Automated provision of clinical routine data for a complex clinical follow-up study: A data warehouse solution

A deep integration of routine care and research remains challenging in many respects. We aimed to show the feasibility of an automated transformation and transfer process feeding deeply structured data with a high level of granularity collected for a clinical prospective cohort study from our hospital information system to the study's electronic data capture system, while accounting for study-specific data and visits. We developed a system integrating all necessary software and organizational processes then used in the study. The process and key system components are described together with descriptive statistics to show its feasibility in general and to identify individual challenges in particular. Data of 2051 patients enrolled between 2014 and 2020 was transferred. We were able to automate the transfer of approximately 11 million individual data values, representing 95% of all entered study data. These were recorded in n = 314 variables (28% of all variables), with some variables being used multiple times for follow-up visits. Our validation approach allowed for constant good data quality over the course of the study. In conclusion, the automated transfer of multi-dimensional routine medical data from HIS to study databases using specific study data and visit structures is complex, yet viable.

[Normocalcemic with elevated post-operative parathormone in primary hyperpara-thyroidism: 9 case reports and literature review]

OBJECTIVE

To summarize and analyze the clinical characteristics of primary hyperpara-thyroidism (PHPT) with normocalcemic parathormone elevation (NPE) after surgical treatment, so as to improve the therapeutic ability and standardized post-operative follow-up of PHPT patients.

METHODS

Nine patients who were diagnosed with PHPT in the Department of Endocrinology of China-Japan Friendship Hospital from August 2017 to November 2019 were selected as the subjects. They all developed NPE within 6 months after surgical treatment. The clinical features and outcomes were collected and analyzed retrospectively, in addition, the related literature was reviewed.

RESULTS

Clinical features: among the 9 patients, 6 were middle-aged and elderly females and 3 were male. The main clinical manifestations were bone pain, kidney stones, nausea and fatigue except for one case of asymptomatic PHPT. Pre-operative examination showed high serum calcium [(3.33±0.48) mmol/L], low serum phosphorus [0.76 (0.74, 0.78) mmol/L], high 24-hour urinary calcium [8.1(7.8, 12.0) mmol/24 h], obviously elevated intact PTH [(546.1±257.7) ng/L], vitamin D deficiency [25-hydroxyvitamin D₃ (21.0±5.7) nmol/L]. Serum levels of bone alkaline phosphatase [7 patients 41.3(38.6, 68.4) μg/L, 2 patients >90 μg/L] and N-terminal midcourse osteocalcin (>71.4 μg/L) were significantly elevated. The estimated glomerular filtration rate decreased in 2 patients. Imaging examination: 7 patients had osteoporosis. Renal calculi were found in 3 patients by renal ultrasound. Imaging examination of parathyroid glands found definite lesions in all the patients, including 2 cases of multiple lesions and 7 cases of single lesions.

TREATMENT AND OUTCOME

two patients underwent parathyroidectomy, while other patients were treated with microwave thermal ablation. PTH increased 1 month after therapy [(255.0±101.4) ng/L], and no recurrent lesions were found by parathyroid ultrasound. After combined treatment with cal-cium and vitamin D for six months, PTH decreased significantly and the level of serum calcium remained normal at anytime during the follow-up period.

CONCLUSION

The occurrence of postoperative NPE may be related to the higher pre-operative PTH, vitamin D deficiency and lower creatinine clearance. However, NPE may not predict recurrent hyperthyroidism or incomplete parathyroidectomy. Adequate calcium and vitamin D supplementation after surgery seems to be beneficial for patients with NPE. Post-operative follow-up of PHPT patients should be standardized to prevent and treat post-operative NPE.

Ectopic Parathyroid Adenoma in an 11-Year-Old Girl: Case Report and Literature Review

Objective

Primary hyperparathyroidism secondary to an ectopic parathyroid adenoma is rare among children and adolescents.

Methods

We describe the case of an 11-year-old girl with incidentally diagnosed primary hyperparathyroidism secondary to an intrathymic parathyroid adenoma and performed a review of the related literature.

Results

^99mTechnetium sestamibi single-photon emission computerized tomography/computed tomography and 4-dimensional computed tomography confirmed the ectopic location of the adenoma. The patient underwent thoracoscopic thymectomy and remained normocalcemic with elevated parathyroid hormone showing a downward trend. Parathyroid hormone normalized 18 months after successful parathyroidectomy.

Conclusion

We review the case of a rare mediastinal parathyroid adenoma in a pediatric patient and summarize the epidemiologic profile, diagnosis, and management of similar pediatric cases.

Bones and Primary Hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a disease caused by excessive and inappropriate secretion of parathyroid hormone resulting in hypercalcemia. It is usually diagnosed incidentally in the face of hypercalcemia, a complication such as osteoporosis or, more rarely, a renal complication with lithiasis. The clinical presentation reflects hypercalcemia and involves several organs, mainly the cardiovascular system, bones, and kidneys. However, most patients with PHPT are asymptomatic. The diagnosis is made based on laboratory tests. It is easy when serum calcium and parathyroid hormone levels are high, but difficult when one of these two values is normal. Normocalcemic PHPT can be diagnosed only after ruling out all causes of secondary hyperparathyroidism. Parathyroid imaging cannot diagnose it but guides the surgeon and rules out an associated thyroid abnormality. The reference treatment is surgery. The surgical indication is based on the presence or risk of complications, and it is the only treatment that prevents fractures. Pharmaceutical treatments have only limited effects on complications and are reserved for cases where surgery is contraindicated. After parathyroid surgery, the use of bisphosphonates must be avoided as they seem to interfere with the parathyroidectomy's fracture-preventing effects. If surgery is not indicated, a plan for monitoring laboratory values, bone density, and renal function will be established.

Bone Turnover Markers in Response to Ultrasound-Guided Microwave Ablation for Primary Hyperparathyroidism

OBJECTIVE

To assess the efficacy and safety of ultrasound-guided microwave ablation (MWA) in the treatment of primary hyperparathyroidism (PHPT), and to investigate whether MWA can improve the bone turnover and renal function.

METHODS

A total of 20 consecutive PHPT patients with 21 parathyroid lesions treated with MWA in our center from May 2019 to March 2021 were recruited in this study. Serum parathyroid hormone (PTH), calcium and phosphorus levels before MWA and at 20 minutes, 4 hours, 1 day, 3 months, 6 months and 12 months after MWA were measured. Bone turnover biomarkers, renal function and lesion volume with volume reduction rate (VRR) before MWA and at the last follow-up were compared. Any complication related with MWA was evaluated. The technical and clinical success rates of MWA in the treatment of PHPT were calculated. Clinical success was defined as normal serum PTH and calcium without PHPT-associated manifestations at more than 6 months after ablation. Technical success was defined as complete ablation indicated by immediate postoperative contrast-enhanced ultrasound.

RESULTS

The serum PTH, calcium and phosphorus levels at their respective follow-up time points dropped significantly after MWA (P <0.05). The volume of parathyroid lesions at the final examination was significantly reduced, compared with pre-ablation volume (P <0.001), with a median VRR reaching 89%. The technical and clinical success rates were 100% and 63.6%, respectively. Substantial changes of bone turnover biomarkers were observed before and after MWA (P <0.05), but the differences in renal function were not statistically significant. No major complications were reported in all cases. Pre-MWA serum PTH, lesion volume, maximum diameter of lesion and ablation time were significantly different between patients with successful and failed MWA.

CONCLUSIONS

PHPT can be effectively and safely treated by ultrasound-guided MWA, as proven by drop in serum PTH and reduction in the volume of parathyroid adenomas. Besides, MWA can impede bone remodeling to suppress hyperparathyroidism in the condition of PHPT.

Low 25-Hydroxyvitamin D in Primary Hyperparathyroidism: Enhanced Conversion Into 1,25-Hydroxyvitamin D May Not Be "True" Deficiency

Vitamin D deficiency is reported in individuals with primary hyperparathyroidism (PHP). However, decreased 25OHD may be attributed to enhanced conversion into 1,25‐hydroxyvitamin D [1,25(OH)D]. To examine vitamin D metabolism in individuals with PHP, serum calcium, PTH, 25OHD, and 1,25(OH)D levels were determined in 210 adults: 102 with PHP, 40 with normal 25OHD, and 68 with vitamin D deficiency. Concentrations were redetermined in 37 individuals with PHP following vitamin D supplementation and 43 patients postsurgery. Comparisons were conducted by Student's t test and ANOVA. Correlations were assessed between PTH and 25OHD, 1,25(OH)D, and 1,25(OH)D/25OHD in individuals with PHP. Calcium, PTH, and 1,25(OH)D were higher (p < 0.001) in individuals with PHP (11.4 ± 0.4, 116 ± 21, 79 ± 6) than in individuals with normal 25OHD (9.6 ± 0.2, 49 ± 5, 57 ± 6) and vitamin D deficiency (9.3 ± 0.2, 62 ± 6, 32 ± 4). Compared with individuals with normal 25OHD (47 ± 5), 25OHD was lower (18 ± 3), but not different from subjects with vitamin D deficiency (15 ± 2). In individuals with PHP, vitamin D2 supplementation induced rises in 1,25(OH)D and calcium without lowering PTH, whereas postsurgery, calcium, PTH, 25OHD, and 1,25(OH)D normalized. Finally, in individuals with PHP, significant correlations (p < 0.01) were documented between PTH and calcium (r = 0.74), 25OHD (r = −0.43), 1,25(OH)D (r = 0.52), and 1,25(OH)D/25OHD (r = 0.46); and between 1,25(OH)D/25OHD and calcium (r = 0.47). Subnormal 25OHD in most individuals with PHP may be attributed to enhanced conversion to 1,25(OH)D—not “true” vitamin D deficiency—although in some patients, both PHP and vitamin D deficiency coexisted. Moreover, vitamin D supplementation exaggerated hypercalcemia in individuals with PHP. © 2020 The Author. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.