Clinical practice. Primary hyperparathyroidism

Sensitivity of 3-Dimensional Sonography in Preoperative Evaluation of Parathyroid Glands in Patients With Primary Hyperparathyroidism

OBJECTIVES

Preoperative localization of parathyroid adenomas in patients with primary hyperparathyroidism facilitates targeted surgery. We assessed the sensitivity of 3-dimensional (3D) sonography for preoperative localization of abnormal parathyroid glands.

METHODS

We conducted a retrospective review of patients who underwent parathyroidectomy for primary hyperparathyroidism at a single site at our institution. We compared preoperative 2-dimensional (2D) sonography, 3D sonography, and sestamibi scans with final gland localization at surgery. Two readers reviewed the sonograms to assess inter-reader variability.

RESULTS

From January 2010 through April 2015, 52 patients underwent parathyroidectomy after preoperative 2D sonography, 3D sonography, and sestamibi scans. Three-dimensional sonography had sensitivity of 88-92% compared with 69-71% for 2D sonography for gland localization. In patients in whom sonography and sestamibi scans localized abnormalities to the same side, the sensitivities were 100% (43 of 43) for 3D sonography and 96% (48 of 50) for 2D sonography. Three-dimensional sonography had significantly higher sensitivity for localization of glands smaller than 500 mg compared with 2D sonography (88% versus 58%; P = .012). There was better inter-reader agreement between the radiologists when using 3D sonography (κ = 0.65) compared with 2D sonography (κ = 0.41).

CONCLUSIONS

We found a significantly higher sensitivity and better inter-reader agreement for 3D sonography compared with 2D sonography for preoperative identification of abnormal parathyroid glands, especially among smaller glands.

Use of a Technetium99m-Sestamibi Scan to Detect Ipsilateral Double Adenoma in a Patient with Primary Hyperparathyroidism: A Case Report

INTRODUCTION

Patients with primary hyperparathyroidism generally have a single parathyroid adenoma that causes excessive excretion of parathyroid hormone. For about 2% to 15% of these patients, a double adenoma is present that involves one lesion on each side of the neck.

CASE PRESENTATION

We describe a case of double parathyroid adenoma causing asymptomatic hypercalcemia. A presurgical technetium99m (Tc99m) sestamibi scan suggested an ipsilateral double adenoma in the left thyroid lobe. An intraoperative parathyroid hormone assay confirmed its successful removal.

DISCUSSION

Although double adenomas are not yet widely acknowledged, presurgical imaging and nuclear scans can help to localize multiple lesions, and intraoperative parathyroid hormone assays can confirm the diagnosis and cure.

Assessing the risk of hypercalcemic crisis in patients with primary hyperparathyroidism

BACKGROUND

Hypercalcemic crisis (HC) is a potentially life-threatening manifestation of primary hyperparathyroidism (PHPT). This study aimed to identify patients with PHPT at greatest risk for developing HC.

METHODS

This retrospective cohort study included patients with a preoperative calcium of at least 12 mg/dL undergoing initial parathyroidectomy for PHPT from 11/2000 to 03/2016. We compared those with HC, defined as needing hospitalization for hypercalcemia, to those without HC.

RESULTS

The study cohort included 29 patients (15.8%) with HC and 154 patients (84.2%) without HC. Demographics and comorbidities were similar between the groups. Patients with HC were more likely to have a history of kidney stones (31.0% versus 14.3%, P = 0.039), higher preoperative calcium (median 13.8 versus 12.4 mg/dL, P < 0.001), higher parathyroid hormone (PTH) (median 318 versus 160 pg/mL, P = 0.001), and lower vitamin D (median 16 versus 26 ng/mL, P < 0.001) than patients without HC. Cure rates with parathyroidectomy were similar, but nearly double the proportion of patients with HC had multigland disease (24.1 versus 12.3%, P = 0.12). In multivariable analysis, higher preoperative calcium (odds ratio [OR] 1.7, 95% confidence interval [CI] 1.1-2.5), higher PTH (OR 1.0, 95% CI 1.0-1.0), and kidney stones (OR 3.0, 95% CI 1.1-8.2) were independently associated with HC. A Classification and Regression Tree revealed that HC developed in 91% of patients with a calcium ≥13.25 mg/dL and a Charlson Comorbidity Index ≥4.

CONCLUSIONS

These data indicate that calcium, PTH, and kidney stones are important in predicting who are at greatest risk of HC. The Classification and Regression Tree can further help stratify risk for developing HC and allow surgeons to expedite parathyroidectomy accordingly.

Hypercalcaemia - presentation and management

Hypercalcaemia is a common disorder normally caused by primary hyperparathyroidism (PHPT) or malignancy. A proportion of cases present as an emergency, which carries a significant mortality. Emergency management of hypercalcaemia is based on intravenous rehydration with normal saline but when this is inadequate, bisphosphonate therapy is used; more recently the novel anti-resorbtive agent denosumab has been shown to have a useful role in treatment. It is estimated that up to 10% of all cases of PHPT presenting under the age of 45 years have an underlying genetic predisposition; nine potentially causative genes are now recognised and may be screened in routine clinical practice. Although parathyroidectomy is the only curative treatment for PHPT, this is indicated in a minority of cases. Many cases can be adequately managed conservatively and guidance from the 4th international workshop on the management of asymptomatic PHPT has recently been updated in a consensus statement.

Parathyroid Diseases and T Cells

PURPOSE OF REVIEW

This review summarizes studies into the permissive role of T cells in the bone catabolic effects of hyperparathyroidism and parathyroid hormone (PTH).

RECENT FINDINGS

Work in animals combined with recent translational studies in humans now highlight the potent amplificatory action of T cells on PTH-induced bone resorption. Mechanistic animal studies reveal a complex pathway by which PTH exploits natural self-renewal functions of CD4⁺ T cells, to drive TNFα production that promotes formation of IL-17A secreting Th17 T cells. TNFα and IL-17 further amplify osteoblastic receptor activator of NF-κB ligand (RANKL) production and down-modulate osteoprotegerin (OPG), establishing conditions propitious for osteoclastic bone resorption. These findings are consistent with, and add to, the traditional view of PTH-induced bone loss involving only osteoblast-lineage cells. T cells potently amplify traditional pathways and provide permissive costimulatory signals to bone marrow stromal cells, facilitating the development of an increased RANKL/OPG ratio favourable to bone resorption and bone loss.

Primary hyperparathyroidism associated to thrombocytopenia: an issue to consider?

Primary hyperparathyroidism (PHPT) is probably the most common endocrine disorder of the parathyroid glands, causing hypercalcemia. It is diagnosed often in persons with elevated serum calcium levels. However, hematological manifestations, such as thrombocytopenia are less known. In this case we describe the possible association of PHPT with reversible thrombocytopenia after parathyroidectomy. This hematological abnormality can be included in the spectrum of possible causes, including seemingly non-specific symptoms, in the decision tree towards surgical assessment.

Skeletal effects of vitamin D deficiency among patients with primary hyperparathyroidism

Little is known about the association between vitamin D deficiency and the skeletal phenotypes in primary hyperparathyroidism (PHPT) patients. A low 25-hydroxyvitamin D level was associated with a low bone mineral density and deteriorated hip geometry in women with PHPT in an Asian population where vitamin D deficiency is prevalent.

INTRODUCTION

Few studies have examined the effect of vitamin D deficiency on the bone health of primary hyperparathyroidism (PHPT) patients.

METHODS

We investigated the skeletal effects of vitamin D deficiency in 79 PHPT patients by assessing bone mineral density (BMD), the trabecular bone score (TBS), and hip geometry, which were measured using dual-energy X-ray absorptiometry (27 men with median age 60 years [53;69]; 52 postmenopausal women with median age of 57 years [53;67]). Cross-sectional data were collected from subjects enrolled in an ongoing PHPT cohort study at Seoul National University Hospital from March 2008 to December 2015.

RESULTS

We classified PHPT patients according to 25-hydroxyvitamin D (25(OH)D) levels (<20 vs. ≥20 ng/ml). After adjusting for age and body mass index, women with vitamin D deficiency had lower BMDs at the lumbar spine (LS) and femur neck (FN) than women who had sufficient levels of vitamin D (LS, 0.903 ± 0.138 vs. 0.998 ± 0.184 g/cm²; FN, 0.715 ± 0.084 vs. 0.791 ± 0.113 g/cm²; P < 0.05). However, the total hip BMD and the TBS were not significantly different between the two groups. In the hip geometry analysis, the cross-sectional area, cross-sectional moment of inertia, and section modulus were also significantly lower in women with vitamin D deficiency than in those without. No significant difference was found in the BMD, TBS, or hip geometry according to 25(OH)D levels in men.

CONCLUSION

Vitamin D deficiency may be associated with a low BMD and deteriorated hip geometry in postmenopausal women with PHPT.

Ethnicity of Patients With Germline GCM2-Activating Variants and Primary Hyperparathyroidism

Context:

Germline gain-of-function variants in the transcription factor GCM2 were found in 18% of kindreds with familial isolated hyperparathyroidism (FIHP). These variants [c.1136T>A (p.Leu379Gln) and c.1181A>C (p.Tyr394Ser)] were located in a 17-amino acid transcriptional inhibitory domain named C-terminal conserved inhibitory domain (CCID).

Objective:

We investigated the ethnicity of individuals with germline variants in the GCM2 CCID in our primary hyperparathyroidism (PHPT) patient samples and in the Genome Aggregation Database.

Design:

Ethnicity information was obtained from an in-house clinical database and genetic counseling. Sanger sequencing of blood DNA was used to determine the genotype of the GCM2 CCID region. Luciferase reporter assays were performed to determine the functional impact of GCM2 variants.

Setting and Patients:

National Institute of Diabetes and Digestive and Kidney Diseases endocrine clinic is a service that accepts PHPT referral patients.

Results:

The GCM2 p.Tyr394Ser variant was found in 41% [95% confidence interval (CI), 22% to 64%] of Ashkenazi Jewish (AJ) kindreds with FIHP and in 27% (95% CI, 17% to 40%) of AJ patients with sporadic PHPT. The p.Tyr394Ser variant was also found in sporadic PHPT patients of European ancestry, but at a lower prevalence. The p.Leu379Gln variant was found in 8% (95% CI, 1% to 26%) of European kindreds with FIHP and 0.5% (95% CI, 0% to 3.0%) of sporadic PHPT cases of European ancestry. The sporadic PHPT patients with GCM2-activating variants often had multigland involvement or postoperative recurrent or persistent disease.

Conclusions:

Specific GCM2-activating variants enriched among various ethnic backgrounds could contribute to a large number of cases with FIHP or sporadic PHPT.

John M. Dynamic Optical Contrast Imaging: A Technique to Differentiate Parathyroid Tissue from Surrounding Tissues

The variable location and indistinct features of parathyroid glands can make their intraoperative identification challenging. Currently, there exists no routine use of localization methods during surgery. Dynamic optical contrast imaging (DOCI) leverages a novel realization of temporally dependent measurements of tissue autofluorescence that allows the acquisition of specific tissue properties. A prospective series of patients with primary hyperparathyroidism was examined. Parathyroid lesions and surrounding tissues were collected; fluorescence decay images were acquired via DOCI. Ex vivo samples (81 patients) were processed for histologic assessment. DOCI extracts relative fluorescence decay information in a surgically relevant field of view with a clinically accessible acquisition time <2 minutes. Analysis of DOCI revealed microscopic characterization sufficient for tissue type identification consistent with histology ( P < .05). DOCI is capable of efficiently distinguishing parathyroid tissue from adjacent tissues. Such an intraoperative tool would be transformative, helping surgeons to identify lesions, preserve healthy tissue, and improve patient outcomes.

Angiotensin-Converting Enzyme Inhibition and Parathyroid Hormone Secretion

BACKGROUND

Prior studies suggest that renin-angiotensin-aldosterone system (RAAS) inhibitors decrease parathyroid hormone (PTH) secretion.

OBJECTIVE

To evaluate the effect of angiotensin-converting enzyme inhibitors (ACEi) on serum PTH in participants with and without primary hyperparathyroidism (P-HPT).

METHODS

An open-label, single-arm, pilot study whereby participants with and without P-HPT had PTH were evaluated before and after 1 week of maximally tolerated lisinopril therapy.

RESULTS

A total of 12 participants with, and 15 participants without, P-HPT successfully completed the protocol. Following 1 week of lisinopril, participants with P-HPT had a decrease in systolic blood pressure (SBP) (-6.4 mmHg, P < 0.01), an increase in plasma renin activity (PRA) (+1.50 ng/mL/h, P = 0.06), and a decrease in PTH (79.5 (21.6) to 70.9 (19.6) pg/mL, ∆ = -8.6 pg/mL, P = 0.049); however, serum and urine calcium did not change. In contrast, although 1 week of lisinopril significantly decreased SBP and increased PRA among participants without P-HPT, there were no changes in PTH or calcium.

CONCLUSION

In this short pilot investigation, 1 week of maximally titrated ACEi did not impact PTH in participants without P-HPT, but resulted in a modest and marginally significant reduction of PTH but not calcium, among participants with P-HPT. This trial is registered with ClinicalTrials.gov NCT01691781.

MECHANISMS IN ENDOCRINOLOGY: Kidney involvement in patients with primary hyperparathyroidism: an update on clinical and molecular aspects

Primary hyperparathyroidism (PHPT) is the third most common endocrine disease. Kidney is a target of both chronic elevated PTH and calcium in PHPT. The classic PHPT complications of symptomatic kidney stones and nephrocalcinosis have become rare and the PHPT current presentation is asymptomatic with uncertain and long-lasting progression. Nonetheless, the routine use of imaging and of biochemical determinations have revealed the frequent occurrence of asymptomatic kidney stones, hypercalciuria and reduced kidney function in asymptomatic PHPT patients. Though the pathogenesis is far from being elucidated, PHPT is associated with reduced renal function, in terms of estimated glomerular filtration rate, and related increased morbidity and mortality. In the last decade, the effort of the Kidney Disease: Improving Global Outcomes (KDIGO) panel of experts highlighted that even mild reduction of kidney function is associated with increased risk of cardiovascular disease. These considerations provided the basis for the Fourth Workshop recommendations of a more extensive diagnostic workout about kidney features and of wider criteria for parathyroid surgery including asymptomatic kidney disease. Moreover, kidney involvement in PHPT is likely to be affected by variants of genes coding the key molecules regulating the calcium and ions renal handling; these features might have clinical relevance and should be considered both during diagnostic workout and follow-up. Finally, the effects of parathyroid surgery and of medical treatment on kidney involvement of PHPT are reviewed.

Endocrine Hypertension: A Practical Approach

Elevated blood pressure resulting from few endocrine disorders (endocrine hypertension) accounts for a high proportion of cases of secondary hypertension. Although some features may be suggestive, many cases of endocrine hypertension remain silent until worked up for the disease. A majority of cases result from primary aldosteronism. Other conditions that can cause endocrine hypertension are: congenital adrenal hyperplasia, Liddle syndrome, pheochromocytomas, Cushing's syndrome, acromegaly, thyroid diseases, primary hyperparathyroidism and iatrogenic hormone manipulation. Early identification and treatment of the cause of endocrine hypertension may help to reduce morbidity and mortality related to these disorders. This article gives a comprehensive and practical approach to the diagnosis and management of endocrine hypertension.

[Intrathyroidal location of parathyroid glands. Atypical presentation of multiple endocrine neoplasia type 1 syndrome]

BACKGROUND

The most common manifestation of MEN 1 syndrome is primary hyperparathyroidism (PHPT) with parathyroid multiglandular affectation. The intrathyroidal situation represents 3-4% of all glands, and it is the second most frequent location in the cervical ectopias.

CLINICAL CASE

11 year old patient, with a family history of MEN1 syndrome and carrier of this same mutation. Patient presents HPTP with osteopenia. The cervical ultrasound shows three compatible images with pathological parathyroid glands (bilateral lower and upper left). The Scan and MRI are normal. Bone densitometry displays data on osteopenia. The patient is surgically intervened, only the upper parathyroid glands are located and removed, after this implantation is performed on the forearm, to prevent the possible devascularization in the dissection of the other glands. However, osteopenia persists and an elevated PTH, therefore new diagnostic tests are held which seem to show two lower parathyroid glands with intrathyroidal location. The patient is reoperated. A subtotal parathyroidectomy of the lower right gland and the resection of the left gland is performed, with the use of intraoperative ultrasound and placement of harpoon. The intraoperative pathology study confirms parathyroid tissue in both cases.

DISCUSSION

It is necessary to locate the parathyroid glands preoperatively in order to alert us of the existence of topographical and ectopia abnormalities, as well as their intrathyroidal location (0.5-3.6%).

CONCLUSION

The intraoperative ultrasound can be a complement to the experience of the endocrine surgeon for the localization of the parathyroid glands and therefore can help determine the best surgical strategy for each clinical case.

Genetics of parathyroid tumours

Primary hyperparathyroidism (PHPT), due to parathyroid tumours, may occur as part of a complex syndrome or as an isolated (nonsyndromic) disorder, and both forms can occur as familial (i.e. hereditary) or nonfamilial (i.e. sporadic) disease. Syndromic PHPT includes multiple endocrine neoplasia (MEN) types 1 to 4 (MEN1 to MEN4) and the hyperparathyroidism-jaw tumour (HPT-JT) syndrome. Syndromic and hereditary PHPT are often associated with multiple parathyroid tumours, in contrast to sporadic PHPT, in which single parathyroid adenomas are more common. In addition, parathyroid carcinomas may occur in ~15% of patients with the HPT-JT syndrome. MEN1 is caused by abnormalities of the MEN1 gene which encodes a tumour suppressor; MEN2 and MEN3 are due to mutations of the rearranged during transfection (RET) proto-oncogene, which encodes a tyrosine kinase receptor; MEN4 is due to mutations of a cyclin-dependent kinase inhibitor (CDNK1B); and HPT-JT is due to mutations of cell division cycle 73 (CDC73), which encodes parafibromin. Nonsyndromic PHPT, which may be hereditary and referred to as familial isolated hyperparathyroidism, may also be due to MEN1, CDC73 or calcium-sensing receptor (CASR) mutations. In addition, ~10% of patients presenting below the age of 45 years with nonsyndromic, sporadic PHPT may have MEN1, CDC73 or CASR mutations, and overall more than 10% of patients with PHPT will have a mutation in one of 11 genes. Genetic testing is available and of value in the clinical setting, as it helps in making the correct diagnosis and planning the management of these complex disorders associated with parathyroid tumours.

GCM2-Activating Mutations in Familial Isolated Hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a common endocrine disease characterized by parathyroid hormone excess and hypercalcemia and caused by hypersecreting parathyroid glands. Familial PHPT occurs in an isolated nonsyndromal form, termed familial isolated hyperparathyroidism (FIHP), or as part of a syndrome, such as multiple endocrine neoplasia type 1 or hyperparathyroidism-jaw tumor syndrome. The specific genetic or other cause(s) of FIHP are unknown. We performed exome sequencing on germline DNA of eight index-case individuals from eight unrelated kindreds with FIHP. Selected rare variants were assessed for co-segregation in affected family members and screened for in an additional 32 kindreds with FIHP. In eight kindreds with FIHP, we identified three rare missense variants in GCM2, a gene encoding a transcription factor required for parathyroid development. Functional characterization of the GCM2 variants and deletion analyses revealed a small C-terminal conserved inhibitory domain (CCID) in GCM2. Two of the three rare variants were recurrent, located in the GCM2 CCID, and found in seven of the 40 (18%) kindreds with FIHP. These two rare variants acted as gain-of-function mutations that increased the transcriptional activity of GCM2, suggesting that GCM2 is a parathyroid proto-oncogene. Our results demonstrate that germline-activating mutations affecting the CCID of GCM2 can cause FIHP.

EZH2 and ZFX oncogenes in malignant behaviour of parathyroid neoplasms

Several studies reported somatic mutations of many genes (MEN1, CTNNB1, CDKIs and others) in parathyroid adenoma, although with different prevalence. Recently, activating mutations of the EZH2 and ZFX oncogenes were identified in benign parathyroid adenoma by whole exome sequencing. The same mutations had been found in blood and ovary malignant tumours. On one hand, this result raised the hypothesis that these oncogenes may play a role in the onset of parathyroid tumour, but it would also suggest they may be involved in malignant, rather benign, parathyroid neoplasm. Our aim was to verify the occurrence of selected mutations of the EZH2 and ZFX genes in an Italian cohort of 23 sporadic parathyroid carcinomas, 12 atypical and 45 typical adenomas. DNA was extracted from paraffin-embedded tissues, PCR amplified and directly sequenced. No mutations were detected in the coding sequence and boundaries of both genes in any of the samples. Two polymorphisms of the EZH2 gene were identified with different prevalence: the rs2072407 variant was present in the 30 % of the samples, in keeping with the overall frequency in larger populations, while the rs78589034 variant, located close to the 5' end of the exon 16, was detected in only one proband with familial isolated hyperparathyroidism; we investigated the possible outcome on the splicing process. EZH2 and ZFX genes do not seem to have an impact on the onset of most parathyroid tumours, both benign and malignant, though further studies on larger cohorts of different ethnicity are needed.

Primary hyperparathyroidism in pregnancy: a case series and literature review

Primary Hyperparathyroidism (PHP) in pregnancy constitutes a serious danger to mother and fetus. The diagnosis of PHP in pregnancy presents a challenge, and PHP commonly goes unidentified and untreated in pregnancy. We present four case reports about patients having PHP, which is very rare condition in pregnancy and their treatment modalities. Three patients, not to be controlled biochemically, denied the parathyroidectomy operation although they are informed about the details of their disease. They are followed up with medical therapy. The first one had no maternal or fetal complications, the second one acquired nephrolithiasis crisis in the last trimester and the third one gave birth to a premature baby who succumbed to tetany. The fourth patient who underwent parathyroidectomy operation in the second trimester had no maternal or fetal complications. PHP in pregnancy is a preventable cause of fetal and maternal mortality and morbidity. Thus, suspecting from PHP during the pregnancy and early diagnosis is critically important in terms of maternal and fetal wellness.

Comparison of minimally invasive parathyroidectomy under local anaesthesia and minimally invasive video-assisted parathyroidectomy for primary hyperparathyroidism: a cost analysis

BACKGROUND

Primary hyperparathyroidism (PHPT) origins from a solitary adenoma in 70- 95% of cases. Moreover, the advances in methods for localizing an abnormal parathyroid gland made minimally invasive techniques more prominent. This study presents a micro-cost analysis of two parathyroidectomy techniques.

PATIENTS AND METHODS

72 consecutive patients who underwent minimally invasive parathyroidectomy, video-assisted (MIVAP, group A, 52 patients) or "open" under local anaesthesia (OMIP, group B, 20 patients) for PHPT were reviewed. Operating room, consumable, anaesthesia, maintenance costs, equipment depreciation and surgeons/anaesthesiologists fees were evaluated. The patient's satisfaction and the rate of conversion to conventional parathyroidectomy were investigated. T-Student's, Kolmogorov-Smirnov tests and Odds Ratio were used for statistical analysis.

RESULTS

1 patient of the group A and 2 of the group B were excluded from the cost analysis because of the conversion to the conventional technique. Concerning the remnant patients, the overall average costs were: for Operative Room, 1186,69 € for the MIVAP group (51 patients) and 836,11 € for the OMIP group (p<0,001); for the Team, 122,93 € (group A) and 90,02 € (group B) (p<0,001); the other operative costs were 1388,32 € (group A) and 928,23 € (group B) (p<0,001). The patient's satisfaction was very strongly in favour of the group B (Odds Ratio 20,5 with a 95% confidence interval).

CONCLUSIONS

MIVAP is more expensive compared to the "open" parathyroidectomy under local anaesthesia due to the costs of general anaesthesia and the longer operative time. Moreover, the patients generally prefer the local anaesthesia. Nevertheless, the rate of conversion to the conventional parathyroidectomy was relevant in the group of the local anaesthesia compared to the MIVAP, since the latter allows a four-gland exploration.

Shear wave elastography and parathyroid adenoma: A new tool for diagnosing parathyroid adenomas

OBJECTIVES

This study prospectively determines the shear wave elastography characteristics of parathyroid adenomas using virtual touch imaging quantification, a non-invasive ultrasound based shear wave elastography method.

METHODS

This prospective study examined 57 consecutive patients with biochemically proven primary hyperparathyroidism and solitary parathyroid adenoma identified by ultrasound and confirmed by at least one of the following: surgical resection, positive Technetium-99m Sestamibi Scintigraphy (MIBI) scan, or fine needle aspiration biopsy with positive PTH washout (performed only in MIBI negative patients). Vascularity and shear wave elastography were performed for all patients. Parathyroid adenoma stiffness was measured as shear wave velocity in meters per second.

RESULTS

The median (range) pre-surgical value for PTH and calcium were 58pg/mL (19, 427) and 10.8mg/dL (9.5, 12.1), respectively. 37 patients had positive MIBI scan. 20 patients had negative MIBI scan but diagnosis was confirmed with positive PTH washout. 42 patients underwent parathyroidectomy, and an adenoma was confirmed in all. The median (range) shear wave velocity for all parathyroid adenomas enrolled in this study was 2.02m/s (1.53, 2.50). The median (range) shear wave velocity for thyroid tissue was 2.77m/s (1.89, 3.70). The shear wave velocity of the adenomas was independent of adenoma size, serum parathyroid hormone concentration, or plasma parathyroid hormone concentration.

CONCLUSIONS

Tissue elasticity of parathyroid adenoma is significantly lower than thyroid tissue. B-mode features and distinct vascularity pattern are helpful tools in diagnosing parathyroid adenoma with ultrasound. Shear wave elastography may provide valuable information in diagnosing parathyroid adenoma.

The changing pattern of diagnosing primary hyperparathyroidism in young patients

BACKGROUND

Primary hyperparathyroidism (PHPT) is increasing in adults but rarely reported in young patients where routine blood work is obtained more judiciously. We aim to determine how PHPT is currently being diagnosed in young patients and examine surgical outcomes.

METHOD

We retrospectively analyzed PHPT patients 24 years of age or less who underwent parathyroidectomy from 2001 to 2014. Patients were divided into 2 time periods: 2001 to 2007 (A) and 2008 to 2014 (B). Incidentally, diagnosed patients lacked objective symptoms of PHPT and had no family history.

RESULTS

Forty young patients met inclusion criteria: 16 in group A and 24 in group B. Those in group A compared with group B had similar mean age, preoperative calcium, and parathyroid hormone (P > .05). Incidental diagnosis was more common in the contemporary group (42% vs 25%, P = .001).

CONCLUSIONS

Current diagnosis of PHPT in young patients is increasingly incidental. This trend may be attributed to the more liberal use of labs in younger patients.

Update on parathyroid carcinoma

INTRODUCTION

Parathyroid carcinoma (PC) is a rare endocrine disorder, commonly causing severe primary hyperparathyroidism (PHPT). PC is mainly a sporadic disease, but it may occur in familial PHPT. Patients with PC usually present markedly elevated serum calcium and PTH. The clinical features are mostly due to the effects of the excessive secretion of PTH rather than to the spread of tumor. At times, the diagnosis can be difficult.

PURPOSE

The aim of this work is to review the available data on PC, and focus its molecular pathogenesis and the clinical utility of CDC73 genetic testing and immunostaining of its product, parafibromin. The pathological diagnosis of PC is restricted to lesions showing unequivocal growth into adjacent tissues or metastasis. Inactivating mutations of the cell division cycle 73 (CDC73) gene have been identified in up to 70 % of apparently sporadic PC and in one-third are germline. Loss of parafibromin immunostaining has been shown in most PC. The association of CDC73 mutations and loss of parafibromin predicts a worse clinical outcome and a lower overall 5- and 10-year survival.

CONCLUSIONS

The treatment of choice is the en bloc resection of the tumor. The course of PC is variable; most patients have local recurrences or distant metastases and die from unmanageable hypercalcemia.

Primary hyperparathyroidism

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

Cancer-Related Hypercalcemia

Hypercalcemia has been reported to occur in up to 30% of patients who have a malignancy. Hypercalcemia is most common in those who have later-stage malignancies and predicts a poor prognosis for those with it. The most common causes include humoral hypercalcemia of malignancy mediated by parathyroid hormone–related peptide, osteolytic cytokine production, and excess 1,25-dihydroxy vitamin D production. However, the etiology is not always mediated by malignancy. Hypercalcemia can occur in those with malignancy and an additional etiology for hypercalcemia such as primary hyperparathyroidism or granulomatous diseases. This paper reviews the cancers associated with hypercalcemia and their proposed mechanisms, nontumor-mediated hypercalcemia, as well as diagnosis and treatment strategies for each condition.

Evaluation of acute and chronic MRI features of sacroiliitis in asymptomatic primary hyperparathyroid patients

Asymptomatic primary hyperparathyroidism (PHPT) is characterized with autonomous overproduction of parathyroid hormone without signs or symptoms associated with hyperparathyroidism. Before symptoms become obvious, PHPT may affect structures like sacroiliac joints, which consist of bone. So, in the asymptomatic PHPT patients, structural and inflammatory changes in sacroiliac joints may lead to confusion during diagnosis workup of axial spondyloarthropathy. In this study, we evaluated active and chronic sacroiliac magnetic resonance imaging (MRI) changes relevant to sacroiliitis in the patients with asymptomatic PHPT and interpreted bone marrow edema within the scope of Assessment of SpondyloArthritis International Society-Outcome Measures in Rheumatology Clinical Trials (ASAS-OMERACT) criteria. Forty-nine patients with asymptomatic PHPT, 26 patients with newly diagnosed axial spondyloarthropathy (SpA), and 37 healthy controls were enrolled. All subjects were evaluated by sacroiliac MRI for four active (bone marrow edema, enthesitis, capsulitis, and synovitis) and four chronic (subchondral sclerosis, subchondral/periarticular erosions, periarticular fat deposition, and bony bridges/ankylosis) lesions relevant to sacroiliitis. Bone marrow edema compatible with ASAS-OMERACT active sacroiliitis criteria in sacroiliac MRI was fulfilled by 16.3 % (8/49) of the asymptomatic PHPT patients which was similar with controls but statistically lower than axial SpA. Moreover, asymptomatic PHPT patients and controls were similar for other chronic or active MRI findings. Also, we detected lower frequency of all other MRI findings, except enthesis, in asymptomatic PHPT patients according to axial SpA. Acute inflammatory including bone marrow edema fulfilling ASAS-OMERACT active sacroiliitis criteria and chronic structural sacroiliac lesions relevant to sacroiliitis in MRI were detected in asymptomatic PHPT similar frequency with controls but as expected, lower than axial SpA. But, these findings could not be attributed to excessive secretion of parathyroid hormone.

Kidney stones and crushed bones secondary to hyperparathyroidism

Here we report a 65-year-old woman with multiple brown tumors and renal stones secondary to primary hyperparathyroidism. This case highlights the need for early recognition of parathyroid hyperactivity.

Intraoperative Parathyroid Hormone Monitoring: Optimal Utilization

Intraoperative parathyroid hormone (IOPTH) monitoring is a highly accurate surgical adjunct used to determine the extent of surgery in the setting of primary hyperparathyroidism. It is the successful interpretation of changes in PTH levels that is essential for using this technique in a way to optimize cure. Thus, it is imperative that the surgeon has an understanding of PTH dynamics and carefully chooses the appropriate IOPTH protocol and interpretation criteria that will best predict operative success, minimize unnecessary bilateral exploration, decrease the likelihood of resecting parathyroid glands that are not hypersecreting, and prevent recurrence.

A nonfunctioning parathyroid carcinoma misdiagnosed as a follicular thyroid nodule

Parathyroid carcinoma (PC) is a rare endocrine malignancy. The tumor is mostly functioning, causing severe primary hyperparathyroidism, with high serum calcium and parathyroid hormone (PTH) levels. Nonfunctioning PC is extremely rare. We report a 50-year-old male patient who was referred to our Department for a right thyroid nodule, incidentally detected on carotid Doppler ultrasound scan, with a fine-needle aspiration cytology showing a follicular lesion. At the time of our evaluation, neck ultrasound showed a 1.3 cm right hypoechoic thyroid nodule with irregular margins and the absence of enlarged bilateral cervical lymph nodes. Thyroid function tests were normal. Serum calcium was normal and plasma PTH slightly above the upper limit of the normal range. The patients underwent right lobectomy. The intraoperative frozen-section pathological examination raised the suspicion of a PC. Definitive histology showed a markedly irregular infiltrative growth of the tumor with invasion of the thyroid tissue and cervical soft tissues. Immunostaining for thyroglobulin was negative, whereas staining for chromogranin A and PTH showed a strong reactivity. Based on the microscopic findings and the immunohistochemical profile, the tumor was diagnosed as a PC. Postoperative serum calcium and phosphate levels were in the normal range. One month after surgery, serum calcium and PTH were normal. Neck ultrasound and total body computed tomography scan were negative for local and metastatic disease. Eight months later, serum calcium was normal and plasma PTH level remained around the upper limit of normal range. Neck ultrasound did not show any pathological lesions. This is the first case of a nonfunctioning sporadic PC misdiagnosed prior of surgery as a follicular thyroid nodule. The parathyroid nature of the neck lesion could not be suspected before surgery. Fine-needle aspiration cytology (FNAC) may fail to distinguish a parathyroid tumor from a benign thyroid nodule because at FNAC, parathyroid and thyroid lesions have some morphological similarities. Histological criteria are not always sufficient for the differential diagnosis, which can definitely be established using immunohistochemistry.

Indocyanine green fluorescence-guided redo parathyroidectomy

Re-operative neck surgery for hyperparathyroidism is a technically difficult operation that requires adjunctive studies to assist with finding the parathyroid tissues. Intraoperative tests help minimise exploration of the neck and decrease injuries to the surrounding structures. Indocyanine green is a near-infrared fluorescent dye that in pre-clinical models was found to be useful in locating the parathyroid glands of dogs. No study has yet reported its use as a tool for parathyroid localisation in humans. We investigated the use of indocyanine green to assist with localisation of a recurrent parathyroid adenoma using a near-infrared imaging system. After exposure of the neck tissues, the parathyroid gland fluoresced brightly and directed our dissection. Exploration of the neck was minimal, and allowed for fast localisation and excision of the adenoma. Overall, use of indocyanine green is a simple and safe technique of intraoperative parathyroid localisation that warrants further investigation.

Normocalcemic primary hyperparathyroidism: a survey in a small village of Southern Italy

We investigated the prevalence of normocalcemic primary hyperparathyroidism (NPHPT) in the adult population living in a village in Southern Italy. All residents in 2010 (n=2045) were invited by calls and 1046 individuals accepted to participate. Medical history, calcium intake, calcium, albumin, creatinine, parathyroid hormone (PTH) and 25OHD were evaluated. NPHPT was defined by normal albumin-adjusted serum calcium, elevated plasma PTH, and exclusion of common causes of secondary hyperparathyroidism (SHPT) (serum 25OHD <30 ng/ml, estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m(2) and thiazide diuretics use), overt gastrointestinal and metabolic bone diseases. Complete data were available for 685 of 1046 subjects. Twenty subjects did not meet the inclusion criteria and 341 could not be evaluated because of thawing of plasma samples. Classical PHPT was diagnosed in four women (0.58%). For diagnosing NPHPT the upper normal limit of PTH was established in the sample of the population (n=100) who had 25OHD ≥30 ng/ml and eGFR ≥60 ml/min per 1.73 m(2) and was set at the mean+3s.d. Three males (0.44%) met the diagnostic criteria of NPHPT. These subjects were younger and with lower BMI than those with classical PHPT. Our data suggest, in line with previous studies, that NPHPT might be a distinct clinical entity, being either an early phenotype of asymptomatic PHPT or a distinct variant of it. However, we cannot exclude that NPHPT might also represent an early phase of non-classical SHPT, since other variables, in addition to those currently taken into account for the diagnosis of NPHPT, might cumulate in a normocalcemic subject to increase PTH secretion.

Minimally invasive parathyroidectomy with or without intraoperative parathyroid hormone for primary hyperparathyroidism

Purpose

The improvement of intraoperative parathyroid hormone (IOPTH) assay and localization studies has enabled a minimally invasive parathyroidectomy (MIP) in primary hyperparathyroidism (pHPT). The aim of this study is to analyze the demographics, clinical presentations, and surgical outcomes of the pHPT patients who received surgical management with versus without IOPTH.

Methods

Analysis of a database was performed on 53 patients who underwent parathyroidectomy for pHPT from 2004 to 2013. Preoperative localization was done by both sestamibi scan and ultrasonography. We divided the patients into two groups (without IOPTH versus with IOPTH) and analyzed the surgical outcomes statistically between two groups.

Results

The concordance rate of Technetium 99m sestamibi scan and ultrasonography was 73.6% and 90.6%, respectively. The overall cure rate of group 1 (without IOPTH) was 94.9% and that of group 2 (with IOPTH) was 100%. The decline of PTH at postoperative 5 minutes and 10 minutes was 75.2% ± 14.9% and 84.9% ± 8.6% in cured patients. On the other hand, that of noncured patients at 5 minutes and 10 minutes was 17.2% ± 9.7% and 8.2% ± 2.2%. There was a significant difference in the drop rate of IOPTH between cured and persistent patients (P < 0.01). Pathological examination showed adenoma in 41 of 53 patients (77.4%) and hyperplasia in 10 of 53 patients (18.9%).

Conclusion

Even though the localization studies were successful, IOPTH monitoring is essential to avoid a surgical failure in MIP.

Clinicopathological correlates of hyperparathyroidism

Hyperparathyroidism is a common endocrine disorder with potential complications on the skeletal, renal, neurocognitive and cardiovascular systems. While most cases (95%) occur sporadically, about 5% are associated with a hereditary syndrome: multiple endocrine neoplasia syndromes (MEN-1, MEN-2A, MEN-4), hyperparathyroidism-jaw tumour syndrome (HPT-JT), familial hypocalciuric hypercalcaemia (FHH-1, FHH-2, FHH-3), familial hypercalciuric hypercalcaemia, neonatal severe hyperparathyroidism and isolated familial hyperparathyroidism. Recently, molecular mechanisms underlying possible tumour suppressor genes (MEN1, CDC73/HRPT2, CDKIs, APC, SFRPs, GSK3β, RASSF1A, HIC1, RIZ1, WT1, CaSR, GNA11, AP2S1) and proto-oncogenes (CCND1/PRAD1, RET, ZFX, CTNNB1, EZH2) have been uncovered in the pathogenesis of hyperparathyroidism. While bi-allelic inactivation of CDC73/HRPT2 seems unique to parathyroid malignancy, aberrant activation of cyclin D1 and Wnt/β-catenin signalling has been reported in benign and malignant parathyroid tumours. Clinicopathological correlates of primary hyperparathyroidism include parathyroid adenoma (80-85%), hyperplasia (10-15%) and carcinoma (<1-5%). Secondary hyperparathyroidism generally presents with diffuse parathyroid hyperplasia, whereas tertiary hyperparathyroidism reflects the emergence of autonomous parathyroid hormone (PTH)-producing neoplasm(s) from secondary parathyroid hyperplasia. Surgical resection of abnormal parathyroid tissue remains the only curative treatment in primary hyperparathyroidism, and parathyroidectomy specimens are frequently encountered in this setting. Clinical and biochemical features, including intraoperative PTH levels, number, weight and size of the affected parathyroid gland(s), are crucial parameters to consider when rendering an accurate diagnosis of parathyroid proliferations. This review provides an update on the expanding knowledge of hyperparathyroidism and highlights the clinicopathological correlations of this prevalent disease.

Changes in the Pattern of Primary Hyperparathyroidism in Czech Republic

Primary hyperparathyroidism (PHPT) is currently the most common endocrine disorder in Czech Republic after diabetes and thyroid diseases particularly in postmenopausal women. Over the past 40 years PHPT has changed from a rare severe disease of the bones and kidneys to common disease with hypertension, peptic ulcer, pancreatitis, easy fatigue and proximal muscle weakness. During 43 years we have examined one of the greatest groups of patients with PHPT. In the early 1970 the estimated incidence of PHPT in former Czechoslovakia was approximately 8 cases per 100 000 persons per year. Our data showed that the incidence of PHPT increased sharply to 24 cases per 100 000 persons per year in same community with the introduction of automated serum calcium and iPTH measurement. The disease is four times more frequent in women as in man. The ratio women to men did not changed since 1981. However the incidence of PHPT changed in Czech Republic from previous years, it develops around the fifth decade of life and is increasingly discovered with advancing age. The incidence of hypertension, diabetes mellitus, cholelithiasis, pancreatitis and peptic ulcer among patients with PHPT is higher as compared with the incidence of these diseases in the general population. However there are still patients suffering from bone and renal complication of PHPT. Removing the adenoma by an experienced surgeon is the first choice of treatment of patients with PHPT. The study offers valuable data on the actual state of hyperparathyroid patients in the Czech Republic.

In vitro diagnostic company recalls and medical laboratory practices: an Italian case

Introduction

In vitro human diagnostic (IVD) company recalls are a common practice aimed to either minimize a potential error or eliminate an existing failure. In this case report, we aim to provide a critical analysis of a recent IVD recall and to provide a practical framework about what to do when an IVD company recalls product(s) based on the International Organization for Standardization - ISO 15189:2012 standard.

Case report

In 2014, Abbott Laboratories® (Green Oaks, IL) published an urgent field safety notice regarding a product recall (Architect Intact parathyroid hormone (PTH) Assay List Number 8K25) with immediate action required. The IVD company explained the reasons for the recall as follows: i) Abbott has confirmed that a performance shift in the Architect Intact PTH assay has the potential to generate falsely elevated results on patient samples; ii) results generated with impacted lots may demonstrate a positive shift relative to those generated with previous reagent and/or calibrator lots. This issue may also impact established Architect Intact PTH reference ranges; iii) the magnitude of shift averages approximately 13% to 45%; iv) Abbott Architect Intact PTH controls do not detect the shift; and v) all current reagent, calibrator, and control inventory are impacted. The recall could have resulted in ~40,000 inaccurate laboratory tests reported by 18 laboratories from Italy (Lombardy region).

Conclusion

IVD company recalls have a serious impact on the patient safety and require a thorough investigation and responsible approach to minimize the possible damage. Medical laboratories accredited according to the ISO 15189 standard have procedures in place to manage such situations and ensure that patient safety is maintained when such recalls are issued.

Follicular lymphoma presenting with hypercalcaemia: an unusual mechanism of hypercalcaemia

Hypercalcaemia is a frequent finding in patients with cancer. In up to 30% of malignancies, the disease course is complicated with hypercalcaemia. For hospitalized patients, cancer is the most common cause of hypercalcaemia. In normal physiological circumstances, the ionized calcium is kept in check by the influence of two important hormones, parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D (1,25(OH)2D). However, cancer can misbalance the calcium homeostasis by generating certain humoural mediators. Overproduction of parathyroid hormone-related peptide (PTH-rp), intact PTH, 1,25(OH)2D, and cytokines all cause hypercalcaemia. Hypercalcaemia is frequent in certain haematological cancers such as multiple myeloma and aggressive lymphomas. But hypercalcaemia is rare in patients with indolent lymphomas such follicular lymphoma. This case illustrates as a first to our knowledge the involvement of cytokines and chemokines in the pathophysiology of lymphoma-related hypercalcaemia. A pathophysiological mechanism is offered based upon the current understanding of cytokines and chemokines related to follicular lymphoma.

Epigenetic alterations in human parathyroid tumors

Epigenetics alterations are involved in tumorigenesis and have been identified in endocrine neoplasia. In particular, DNA methylation, microRNAs deregulations and histone methylation impairment are detected in tumors of the parathyroid glands. Parathyroid tumors are the second most common endocrine neoplasia following thyroid cancer in women, and it is associated with primary hyperparathyroidism, a disease sustained by PTH hypersecretion. Despite the hallmark of global promoter hypomethylations was not detectable in parathyroid tumors, increase of hypermethylation in specific CpG islands was detected in the progression from benign to malignant parathyroid tumors. Furthermore, deregulation of a panel of embryonic-related microRNAs (miRNAs) was documented in parathyroid tumors compared with normal glands. Impaired expression of the histone methyltransferases EZH2, BMI1, and RIZ1 have been described in parathyroid tumors. Moreover, histone methyltransferases have been shown to be modulated by the oncosuppressors HIC1, MEN1, and HRPT2/CDC73 gene products that characterize tumorigenesis of parathyroid adenomas and carcinomas, respectively. The epigenetic scenario in parathyroid tumors have just began to be decoded but emerging data highlight the involvement of an embryonic gene signature in parathyroid tumor development.

Primary hyperparathyroidism and vitamin D deficiency

Primary hyperparathyroidism (PHPT) and vitamin D (VD) deficiency are frequent conditions due to the widespread application of assays for calcium and VD. PHPT presentation is dominated by diversity in its expression and the current predominance of asymptomatic forms. VD, which plays a major role in calcium and phosphate homeostasis, is also involved in many physiological processes in this disease, such as lipid and glucose metabolism, and in the signalling pathways and functioning of many cell types. The bone and cardiometabolic complications described in PHPT are exacerbated by vitamin D deficiency, the prevalence of which varies according to many parameters (environment, skin pigmentation, associated chronic diseases, liver and kidney function, assay kit used, etc.). In response to this observation, experts in field from medical societies validated the indication for systematic assay of VD occurring with PHPT and the need for replacement in case of deficiency. Several epidemiological studies have confirmed that replacement with natural vitamin D is well tolerated and safe in subjects with PHPT and VD deficiency. This supplementation reduces hyperparathormonemia, does not have symptomatic effects on calciuria, and especially improves the bone and functional condition of patients.

Functional characterization of a CDKN1B mutation in a Sardinian kindred with multiple endocrine neoplasia type 4 (MEN4)

Inactivating germline mutations of the CDKN1B gene, encoding for the nuclear cyclin-dependent kinase inhibitor p27kip1 protein, have been reported in patients with multiple endocrine neoplasia type 4 (MEN4), a MEN1-like phenotype without MEN1 mutations. The aim of this study was to in vitro characterize the germline CDKN1B mutation c.374_375delCT (S125X) we detected in a patient with MEN4. The proband was affected by multiglandular primary hyperparathyroidism and gastro-entero-pancreatic tumors. We carried out subcellular localization experiments transfecting into eukaryotic HeLa and GH3 cell lines plasmid vectors expressing the CDKN1B wild type (wt) or mutant cDNA. Western blot studies showed that fusion proteins were expressed at equal levels. The mutated protein was shorter compared to the wt protein and lacked the highly conserved C-terminal domain, which includes the bipartite nuclear localization signal at amino acids 152/153 and 166/168. In HeLa and GH3 cells wt p27 localized in the nucleus whereas the p27_S125X protein was retained in the cytoplasm predicting the loss of tumor suppressive function. The proband's tumoral parathyroid tissue did not show allelic loss, since wt and mutant alleles were both present by sequencing the somatic DNA. Immunohistochemistry showed a complete loss of nuclear p27 expression in the parathyroid adenoma removed by the patient at the second surgery. In conclusion, our study confirms the pathogenic role of the c.374_375delCT CDKN1B germline mutation in a patient with MEN4.

Rare diseases in clinical endocrinology: a taxonomic classification system

PURPOSE

Rare endocrine-metabolic diseases (REMD) represent an important area in the field of medicine and pharmacology. The rare diseases of interest to endocrinologists involve all fields of endocrinology, including rare diseases of the pituitary, thyroid and adrenal glands, paraganglia, ovary and testis, disorders of bone and mineral metabolism, energy and lipid metabolism, water metabolism, and syndromes with possible involvement of multiple endocrine glands, and neuroendocrine tumors. Taking advantage of the constitution of a study group on REMD within the Italian Society of Endocrinology, consisting of basic and clinical scientists, a document on the taxonomy of REMD has been produced.

METHODS AND RESULTS

This document has been designed to include mainly REMD manifesting or persisting into adulthood. The taxonomy of REMD of the adult comprises a total of 166 main disorders, 338 including all variants and subtypes, described into 11 tables.

CONCLUSIONS

This report provides a complete taxonomy to classify REMD of the adult. In the future, the creation of registries of rare endocrine diseases to collect data on cohorts of patients and the development of common and standardized diagnostic and therapeutic pathways for each rare endocrine disease is advisable. This will help planning and performing intervention studies in larger groups of patients to prove the efficacy, effectiveness, and safety of a specific treatment.

Intraoperative scintigraphy using a large field-of-view portable gamma camera for primary hyperparathyroidism: initial experience

Background. We investigated a novel technique, intraoperative ^99 mTc-Sestamibi (MIBI) imaging (neck and excised specimen (ES)), using a large field-of-view portable gamma camera (LFOVGC), for expediting confirmation of MIBI-avid parathyroid adenoma removal. Methods. Twenty patients with MIBI-avid parathyroid adenomas were preoperatively administered MIBI and intraoperatively imaged prior to incision (neck) and immediately following resection (neck and/or ES). Preoperative and intraoperative serum parathyroid hormone monitoring (IOPTH) and pathology (path) were also performed. Results. MIBI neck activity was absent and specimen activity was present in 13/20 with imaging after initial ES removal. In the remaining 7/20 cases, residual neck activity and/or absent ES activity prompted excision of additional tissue, ultimately leading to complete hyperfunctioning tissue excision. Postexcision LFOVGC ES imaging confirmed parathyroid adenoma resection 100% when postresection imaging qualitatively had activity (ES) and/or no activity (neck). The mean ± SEM time saving using intraoperative LFOVGC data to confirm resection versus first IOPTH or path result would have been 22.0 ± 2 minutes (specimen imaging) and 26.0 ± 3 minutes (neck imaging). Conclusion. Utilization of a novel real-time intraoperative LFOVGC imaging approach can provide confirmation of MIBI-avid parathyroid adenoma removal appreciably faster than IOPTH and/or path and may provide a valuable adjunct to parathyroid surgery.

Hypercalcemic crisis due to primary hyperparathyroidism occurring concomitantly with Graves' disease

We herein describe a case of hypercalcemic crisis in a 52-year-old Japanese woman. She suffered from thirst and fatigue for one month. Her serum calcium (a) levels were 19.0 mg/dL, and she was diagnosed with hypercalcemic crisis. Circulating levels of parathyroid and thyroid hormones were elevated. She was diagnosed with primary hyperparathyroidism accompanied by Graves' disease. Thyroparathyroidectomy was performed after circulating levels of Ca and thyroid hormones were normalized. Both of primary hyperparathyroidism and Graves' disease can contribute and accelerate hypercalcemia, resulting in a state of crisis. The possibility of their coexistence should therefore be taken into consideration in cases of hypercalcemia.

Preoperative localization and intraoperative parathyroid hormone assay in korean patients with primary hyperparathyroidism

BACKGROUND

The intraoperative parathyroid hormone (IOPTH) assay is widely used in patients with primary hyperparathyroidism (PHPT). We investigated the usefulness of the IOPTH assay in Korean patients with PHPT.

METHODS

We retrospectively reviewed the data of 33 patients with PHPT who underwent parathyroidectomy. Neck ultrasonography (US) and 99mTc-sestamibi scintigraphy (MIBI scan) were performed preoperatively and IOPTH assays were conducted.

RESULTS

The sensitivity of neck US and MIBI scans were 91% and 94%, respectively. A 50% decrease in parathyroid hormone (PTH) levels 10 minutes after excision of the parathyroid gland was obtained in 91% (30/33) of patients and operative success was achieved in 97% (32/33) of patients. The IOPTH assay was 91% true-positive, 3% true-negative, 0% false-positive, and 6% false-negative. The overall accuracy of the IOPTH assay was 94%. In five cases with discordant neck US and MIBI scan results, a sufficient decrease in IOPTH levels helped the surgeon confirm the complete excision of the parathyroid gland with no additional neck exploration.

CONCLUSION

The IOPTH assay is an accurate tool for localizing hyperfunctioning parathyroid glands and is helpful for evaluating cases with discordant neck US and MIBI scan results.

Comparison of 4D CT, ultrasonography, and 99mTc sestamibi SPECT/CT in localizing single-gland primary hyperparathyroidism

OBJECTIVE

The present study was designed to evaluate 4D computerized tomography (CT) as a means of localizing abnormal parathyroid glands in primary hyperparathyroidism (HPT).

STUDY DESIGN

Case series with expertized image review.

SETTING

Tertiary care hospital.

SUBJECTS AND METHODS

A total of 38 patients were recruited for study, all of whom had undergone focused parathyroidectomy for single-lesion primary HPT between June 2011 and September 2013. In each patient, 3 imaging procedures were performed: cervical ultrasonography (US), 99mTc-sestamibi SPECT/CT (SeS), and 4D CT. Collective imaging data were blindly reviewed and compared.

RESULTS

4D CT outperformed US and SeS in terms of sensitivity (P=.27), specificity (P=.01), positive predictive value (PPV) (P<.01), negative predictive value (NPV) (P=.19), and accuracy (P<.01). In 7.9% (3/38) of patients, 4D CT provided specific anatomic information that was unaffordable by US and SeS. Localization by 4D CT correlated with tissue parathyroid hormone level (P=.02), maximum diameter (P=.01), and volume (P<.01) of abnormal parathyroid glands.

CONCLUSION

4D CT proved helpful in localizing target parathyroid glands of primary HPT that were missed by traditional imaging.