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

Characteristics, management and outcomes of primary hyperparathyroidism from 2009 to 2021: a single centre report from South Africa

BACKGROUND

There has been a notable shift towards the diagnosis of less severe and asymptomatic primary hyperparathyroidism (PHPT) in developed countries. However, there is a paucity of recent data from sub-Saharan Africa (SSA), and also, no reported data from SSA on the utility of intra-operative parathyroid hormone (IO-PTH) monitoring. In an earlier study from Inkosi Albert Luthuli Central Hospital (IALCH), Durban, South Africa (2003-2009), majority of patients (92.9%) had symptomatic disease. The aim of this study was to evaluate the clinical profile and management outcomes of patients presenting with PHPT at IALCH.

METHODS

A retrospective chart review of patients with PHPT attending the Endocrinology clinic at IALCH between July 2009 and December 2021. Clinical presentation, laboratory results, radiologic findings, surgical notes and histology were recorded.

RESULTS

Analysis included 110 patients (87% female) with PHPT. Median age at presentation was 57 (44; 67.5) years. Symptomatic disease was present in 62.7% (n:69); 20.9% (n:23) had a history of nephrolithiasis and 7.3% (n:8) presented with previous fragility fractures. Mean serum calcium was 2.87 ± 0.34 mmol/l; median serum-PTH was 23.3 (15.59; 45.38) pmol/l, alkaline phosphatase 117.5 (89; 145.5) U/l and 25-hydroxyvitamin-D 42.9 (33.26; 62.92) nmol/l. Sestamibi scan (n:106 patients) identified an adenoma in 83.02%. Parathyroidectomy was performed on 84 patients with a cure rate of 95.2%. Reasons for conservative management (n:26) included: no current surgical indication (n:7), refusal (n:5) or deferral of surgery (n:5), loss to follow-up (n:5) and assessed as high anaesthetic risk (n:4). IO-PTH measurements performed on 28 patients indicated surgical success in 100%, based on Miami criteria. Histology confirmed adenoma in 88.1%, hyperplasia in 7.1% and carcinoma in 4.8%. Post-operative hypocalcaemia developed in 30 patients (35.7%), of whom, 14 developed hungry bone syndrome (HBS). In multivariate analysis, significant risk factors associated with HBS included male sex (OR 7.01; 95% CI 1.28, 38.39; p 0.025) and elevated pre-operative PTH (OR 1.01; 95% CI 1.00, 1.02; p 0.008).

CONCLUSIONS

The proportion of asymptomatic PHPT has increased at this centre over the past decade but symptomatic disease remains the dominant presentation. Parathyroidectomy is curative in the majority of patients. IO-PTH monitoring is valuable in ensuring successful surgery.

A Case of TKA Failure in Patient with Primary Hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (PHPT) is an endocrine disorder with high serum calcium and parathyroid hormone (PTH) levels. Excessive secretion of PTH can cause bone loss and may have potential damage to implant fixation after total knee arthroplasty (TKA). However, there is currently no research or literature reporting prosthesis loosening after TKA associated with PHPT.

CASE PRESENTATION

This case report describes a TKA failure of tibial prothesis loosening associated with PHPT. The patient faced aggravated pain and difficulty in walking 6 months after the primary TKA. Further examinations showed high serum calcium and PTH levels indicating the presence of PHPT. After the surgery of parathyroidectomy, the patient received revision TKA with 3D-printed metaphyseal cone. Knee symptoms and function were finally improved.

CONCLUSION

PHPT is a risk factor for prosthesis loosening after TKA. Preoperative screening test of serum calcium and PTH levels is important to diagnose PHPT. For patients with PHPT undergoing TKA, preoperative endocrinotherapy and parathyroidectomy are recommended to improve the survival of prosthesis.

Genomic Profiling Reveals the Variant Landscape of Sporadic Parathyroid Adenomas in Chinese Population

OBJECTIVE

To define somatic variants of parathyroid adenoma (PA) and to provide novel insights into the underlying molecular mechanism of sporadic PA.

METHODS

Basic clinical characteristics and biochemical indices of 73 patients with PA were collected. Whole-exome sequencing was performed on matched tumor-constitutional DNA pairs to detect somatic alterations. Functional annotation was carried out by ingenuity pathway analysis afterward. The protein expression of the variant gene was confirmed by immunohistochemistry, and the relationship between genotype and phenotype was analyzed.

RESULTS

Somatic variants were identified in 1549 genes, with an average of 69 variants per tumor (range, 13-2109; total, 9083). Several novel recurrent somatic variants were detected, such as KMT2D (15/73), MUC4 (14/73), POTEH (13/73), CD22 (12/73), HSPA2 (12/73), HCFC1 (11/73), MAGEA1 (11/73), and SLC4A3 (11/73), besides the previously reported PA-related genes, including MEN1 (11/73), CASR (6/73), MTOR (4/73), ASXL3 (3/73), FAT1 (3/73), ZFX (5/73), EZH1 (2/73), POT1 (2/73), and EZH2 (1/73). Among them, KMT2D might be the candidate driver gene of PA. Crucially, 5 patients carried somatic mutations in CDC73, showed an aggressive phenotype similar to that of parathyroid carcinoma (PC), and had a decreased expression of parafibromin. Pathway analysis of recurrent potential PA-associated driver variant genes revealed functional enrichments in the signaling pathway of Notch.

CONCLUSION

Our study expanded the pathogenic variant spectrum of PA and indicated that KMT2D might be a novel candidate driver gene and be considered as a diagnostic biomarker for PA. Meanwhile, CDC73 mutations might be an early developmental event from PA to PC. The results provided insights into elucidating the pathogenesis of parathyroid tumorigenesis and a certain basis for clinical diagnosis and treatment.

Clinical and genetic analysis of atypical parathyroid adenoma compared with parathyroid carcinoma and benign lesions in a Chinese cohort

CONTEXT

The malignant potential and molecular signature of atypical parathyroid adenoma (APA) remain elusive. Data from Asia are still lacking.

DESIGN AND SETTING

This was a retrospective study on a large APA cohort in a single center from mainland China.

METHODS

A total of 320 patients with primary hyperparathyroidism (PHPT), containing 79 APA, 79 Parathyroid cancer (PC) and 162 benign lesions cases, were enrolled after surgery for collection of clinical data and genetic analysis.

RESULTS

APA patients showed earlier mean onset age than benign group (46.9 ± 17.1 vs. 52.0 ± 14.3 yrs). Less bone involvement and gastrointestinal symptoms were presented in APA compared to PC (35.4% vs. 62.0%, and 17.7% vs. 41.8%), while more urolithiasis was seen in APA than in benign lesions (57.0% vs. 29.6%). The APA group had moderate hypercalcemia (mean 3.02 ± 0.44mmol/L) with elevated serum PTH (median 593.0pg/ml) and proportion of hypercalcemic crisis as 22.8%, all higher than those of benign lesions but lower than those of PC group. The recurrence/no remission rate of the APA group was significantly lower than that of the PC and similar to the benign group (5.1% vs. 31.6% vs. 3.1%). Germline CDC73 mutation was the most common molecular abnormality in both PC and APA subjects. APA patients with nonsynonymous germline variants showed earlier onset age (28.5 ± 16.9 vs. 48.1 ± 17.7 yrs) and more cases developing no remission/recurrence (25.0% vs. 0.0%).

CONCLUSIONS

Patients with APA presented clinical and biochemical characteristics much less severe than PC and resembling the benign neoplasms, with a relatively good prognosis. Germline gene variations were associated with earlier onset and probably more recurrence of PHPT in APA.

The preliminary study on cardiac structure and function in Chinese patients with primary hyperparathyroidism

PURPOSE

Recent evidences show that primary hyperparathyroidism (PHPT) patients have a high prevalence of cardiovascular diseases. However, the reported changes in cardiac status are inconsistent in previous studies. The present work evaluated the cardiac structure and function in PHPT patients by echocardiography.

METHODS

PHPT patients and age- and sex-matched healthy controls were enrolled in this case-control study. Biochemical parameters were retrospectively collected from PHPT patients. Cardiac function and structure were assessed in all subjects using echocardiography.

RESULTS

A total of 153 PHPT patients and 51 age- and sex-matched healthy controls were enrolled in this study. The mean serum calcium and parathyroid hormone (PTH) levels in PHPT patients were 2.84 ± 0.28mmol/L and 206.9 (130.0, 447.5) pg/ml, respectively. Left ventricular ejection fraction (LVEF) and early to late mitral annular velocity (E/A) were significantly lower in PHPT patients than in healthy controls (68.2 ± 6.0 vs. 70.7 ± 16.7%, 1.0 ± 0.5 vs. 1.4 ± 0.5, respectively, p both < 0.05). The left ventricular mass index (LVMI) and the relative wall thickness (RWT) were not significantly different between the two groups. However, the difference in LVEF between PHPT patients without hypertension and diabetes and the control groups disappeared. The majority of PHPT patients had normal cardiac geometry; however, a proportion of them exhibited concentric remodeling (normal LVMI, RWT≥0.42). Serum calcium, corrected calcium, ionized calcium and PTH were inversely related to E/A, whereas serum phosphorus and 24-hour urine calcium were positively related to E/A. Furthermore, biochemical parameters were not correlated with LVEF.

CONCLUSIONS

These findings demonstrate that PHPT patients exhibit diastolic cardiac dysfunction reflected by decreased E/A, as well as possible cardiac structural abnormalities. The serum calcium, phosphorus, and parathyroid hormone levels may influence cardiac structure and function.

Immunohistochemical Profile of Parathyroid Tumours: A Comprehensive Review

Immunohistochemistry remains an indispensable tool in diagnostic surgical pathology. In parathyroid tumours, it has four main applications: to detect (1) loss of parafibromin; (2) other manifestations of an aberrant immunophenotype hinting towards carcinoma; (3) histogenesis of a neck mass and (4) pathogenetic events, including features of tumour microenvironment and immune landscape. Parafibromin stain is mandatory to identify the new entity of parafibromin-deficient parathyroid neoplasm, defined in the WHO classification (2022). Loss of parafibromin indicates a greater probability of malignant course and should trigger the search for inherited or somatic CDC73 mutations. Aberrant immunophenotype is characterised by a set of markers that are lost (parafibromin), down-regulated (e.g., APC protein, p27 protein, calcium-sensing receptor) or up-regulated (e.g., proliferation activity by Ki-67 exceeding 5%) in parathyroid carcinoma compared to benign parathyroid disease. Aberrant immunophenotype is not the final proof of malignancy but should prompt the search for the definitive criteria for carcinoma. Histogenetic studies can be necessary for differential diagnosis between thyroid vs. parathyroid origin of cervical or intrathyroidal mass; detection of parathyroid hormone (PTH), chromogranin A, TTF-1, calcitonin or CD56 can be helpful. Finally, immunohistochemistry is useful in pathogenetic studies due to its ability to highlight both the presence and the tissue location of certain proteins. The main markers and challenges (technological variations, heterogeneity) are discussed here in the light of the current WHO classification (2022) of parathyroid tumours.

Overview of the 2022 WHO Classification of Parathyroid Tumors

The 2022 WHO classification reflects increases in the knowledge of the underlying pathogenesis of parathyroid disease. In addition to the classic characteristic features of parathyroid neoplasms, subtleties in histologic features which may indicate an underlying genetic abnormality reflect increased understanding of the clinical manifestations, histologic, and genetic correlation in parathyroid disease. The importance of underlying genetic aberrancies is emphasized due to their significance to the care of the patient. Traditionally, the term "parathyroid hyperplasia" has been applied to multiglandular parathyroid disease; however, the concept of hyperplasia is generally no longer supported in the context of primary hyperparathyroidism since affected glands are usually composed of multiple "clonal" neoplastic proliferations. In light of these findings and management implications for patient care, the 2022 WHO classification endorses primary hyperparathyroidism-related multiglandular parathyroid disease (multiglandular multiple parathyroid adenomas) as a germline susceptibility-driven multiglandular parathyroid neoplasia. From such a perspective, pathologists can provide additional value to genetic triaging by recognizing morphological and immunohistochemical harbingers of MEN1, CDKN1B, MAX, and CDC73-related manifestations. In the current WHO classification, the term "parathyroid hyperplasia" is now used primarily in the setting of secondary hyperplasia which is most often caused by chronic renal failure. In addition to expansion in the histological features, including those that may be suggestive of an underlying genetic abnormality, there are additional nomenclature changes in the 2022 WHO classification reflecting increased understanding of the underlying pathogenesis of parathyroid disease. The new classification no longer endorses the use of "atypical parathyroid adenoma". This entity is now being replaced with the term of "atypical parathyroid tumor" to reflect a parathyroid neoplasm of uncertain malignant potential. The differential diagnoses of atypical parathyroid tumor are discussed along with the details of worrisome clinical and laboratory findings, and also features that define atypical histological and immunohistochemical findings to qualify for this diagnosis. The histological definition of parathyroid carcinoma still requires one of the following findings: (i) angioinvasion (vascular invasion) characterized by tumor invading through a vessel wall and associated thrombus, or intravascular tumor cells admixed with thrombus, (ii) lymphatic invasion, (iii) perineural (intraneural) invasion, (iv) local malignant invasion into adjacent anatomic structures, or (v) histologically/cytologically documented metastatic disease. In parathyroid carcinomas, the documentation of mitotic activity (e.g., mitoses per 10mm²) and Ki67 labeling index is recommended. Furthermore, the importance of complete submission of parathyroidectomy specimens for microscopic examination, and the crucial role of multiple levels along with ancillary biomarkers have expanded the diagnostic workup of atypical parathyroid tumors and parathyroid carcinoma to ensure accurate characterization of parathyroid neoplasms. The concept of parafibromin deficiency has been expanded upon and term "parafibromin deficient parathyroid neoplasm" is applied to a parathyroid neoplasm showing complete absence of nuclear parafibromin immunoreactivity. Nucleolar loss is considered as abnormal finding that requires further molecular testing to confirm its biological significance. The 2022 WHO classification emphasizes the role of molecular immunohistochemistry in parathyroid disease. By adopting a question-answer framework, this review highlights advances in knowledge of histological features, ancillary studies, and associated genetic findings that increase the understanding of the underlying pathogenesis of parathyroid disease that are now reflected in the updated classification and new entities in the 2022 WHO classification.

Association of Famine Exposure on the Changing Clinical Phenotypes of Primary Hyperparathyroidism in 20 years

BACKGROUND & AIMS

Primary hyperparathyroidism(PHPT) has been evolving into a milder asymptomatic disease. No study has assessed the association between famine exposure and such a shift. We aim to explore the effects of China's Great Famine exposure on the changing pattern of PHPT phenotypes.

METHODS

750 PHPT patients diagnosed from 2000 to 2019 were studied. The clinical presentations were compared between them in recent 10 years (2010-2019) and previous 10 years (2000-2009). Participants were then categorized into fetal, childhood, adolescent, adult exposure, and unexposed groups. Logistic regression was used to estimate the odds ratios (ORs) and confidence intervals (CIs) of famine exposure as factors contributing to the changes in the clinical presentations of PHPT.

RESULTS

Serum levels of PTH, albumin-corrected Ca, tumor size, eGFR, BMDs (all P<0.001), and clinical symptoms became milder in recent 10 years. Famine exposure (72.6% vs 58.4%, P<0.001), especially the adult exposure (18.8% vs 4.1%, P<0.001)was significant less in recent 10 years. The ORs (95%CIs) of having upper 3^rd tertile PTH were 2.79(1.34,5.8), 2.07(1.04,4.11), 3.10(1.15,8.38) and 8.85(2.56,30.56) for patients with fetal, childhood, adolescent and adult famine exposure, respectively. The ORs (95%CIs) of upper 3^rd tertile albumin-corrected Ca and upper 3^rd tertile of tumor size was 4.78(1.39, 16.38) and 4.07(1.12,14.84) for participants with adult famine exposure, respectively. All these associations were independent of age, sex, disease duration and other confounders.

CONCLUSIONS

The clinical manifestations of PHPT in China continue to be milder. Exposure to famine is associated with PHPT. Less famine exposure might be responsible for the mile form of PHPT in recent years.

Changes in clinical patterns of Chinese patients with primary hyperparathyroidism in the past 12 years: a single-center experience

The clinical presentation of primary hyperparathyroidism (PHPT) differs between patients from developed and developing countries. In China, the clinical pattern has changed over the past few decades. Our aim was to elucidate general changes in the clinical characteristics of PHPT from 2010 to 2021. We enrolled 343 patients with PHPT at the Qilu Hospital of Shandong University, Jinan, China, from January 2010 to May 2021, including both surgical and non-surgical patients. Patients were divided into two subgroups, 2010-2016 (group A, n = 152) and 2017-2021 (group B, n = 191), based on the time span. We compared clinical manifestations and laboratory result data between these two groups. The mean patient age was 52.59 ± 13.55 years, and the male-to-female ratio was 1:2.54. Of the 343 patients, 183 (53.35%) had symptomatic PHPT; bone pain, urolithiasis, and fatigue were the most common symptoms. Post-operative pathology showed that 96.20% of the patients had parathyroid adenoma, whereas 2.41% had parathyroid carcinoma. Great changes occurred between 2010 and 2021; the percentage of patients with asymptomatic PHPT (aPHPT) increased from 36.18% in group A to 54.97% in group B. Moreover, patients in group B showed significantly lower serum calcium, alkaline phosphatase, parathyroid hormone, and urinary phosphate levels but higher serum 25-hydroxyvitamin D levels than those in group A. Clinical presentations in group B were also milder. In conclusion, the clinical characteristics of Chinese PHPT patients changed dramatically from 2010 to 2021, with asymptomatic PHPT (aPHPT becoming the predominant type over the last 3 years.