A systematic review of the diagnosis and treatment of primary hyperparathyroidism from 1995 to 2003

Frequency and characteristics of ectopic parathyroid adenomas in a cohort of patients referred for 18F-fluorocholine PET/CT

AIM

This article aimed to study the frequency and characteristics of ectopic/intrathyroidal parathyroid adenomas in patients referred for 18F-fluorocholine PET/computed tomography (CT).

PATIENTS AND METHODS

From 11 June 2015 to 15 January 2024, 729 patients were studied. Recorded patient variables included hyperparathyroidism type, sex, age, presence of symptoms, renal involvement, bone involvement, parathyroid hormone (PTH), and serum calcium, phosphate, and vitamin D as well as 24-h urine calcium excretion. PET/CT results were also collected. In case of parathyroidectomy, the weight of the adenomas was recorded. Continuous variables were expressed as mean ± SD. Differences were evaluated with Mann-Whitney U-tests or two-sample t-tests, when appropriate. P-values ≤0.05 were considered statistically significant.

RESULTS

PET/CT showed no adenoma in 163 (22%), adenoma in 451 (62%), hyperplasia/multiglandular disease in 32 (4%), and equivocal results in 83 (11%) patients. A total of 6/729 (1%) adenomas were located intrathyroidally and 16/729 (2%) had an ectopic location. Patients with ectopic/intrathyroidal adenoma showed significantly higher serum PTH levels than patients with no visualization of adenoma on PET. The mean mass of the adenoma was 1 ± 2.3 g in patients with orthotopic adenomas versus 2.7 ± 3.3 g in patients with ectopic/intrathyroidal adenomas; however, this was not significantly different (P = 0.09).

CONCLUSION

In the presented cohort, the frequency of ectopic/intrathyroidal parathyroid adenomas was 3%. No significant difference in weight was found between orthotopic and ectopic/intrathyroidal parathyroid adenomas.

Refining the role of presurgical PET/4D-CT in a large series of patients with primary hyperparathyroidism undergoing [18F]Fluorocholine PET/CT

BACKGROUND

4D-CT has garnered attention as complementary imaging for patients with primary hyperparathyroidism (pHPT). Herein we evaluated a diagnostic strategy using [18F]Fluorocholine Positron Emission Tomography/Computed Tomography (PET/CT), followed by 4D-CT integrated into PET/4D-CT after negative/inconclusive PET/CT results in a single-center retrospective cohort of 166 pHPT patients who underwent parathyroidectomy after [18F]Fluorocholine PET/4D-CT.

METHODS

PET/CT and 4D-CT images were interpreted by three nuclear medicine physicians and one expert radiologist. Pathological findings were documented, and concordance rates were assessed. PET/CT results were categorized as positive/negative, with positive cases rated on a 3-level certitude scale: low, moderate, high. Inconclusive cases included low/moderate positivity. The added value of PET/4D-CT was assessed for negative/inconclusive cases through joint reading.

RESULTS

PET/CT lesion-based analysis showed almost perfect interobserver concordance (Cohen's kappa >.8). Across the cohort, PET/CT had a sensitivity of 83%, specificity of 97%, PPV of 90% and NPV of 94%. For 4D-CT, these values were sensitivity: 53%, specificity: 84%, PPV: 56% and NPV: 82%. PET/CT was significantly more accurate than 4D-CT. Among 44 patients with negative/inconclusive results, PET/CT had sensitivity: 60%, specificity: 91%, PPV: 71% and NPV: 86%. In the same patients, sensitivity and specificity of the sequential diagnostic algorithm increased to 80% and 97%, showing significantly better global accuracy (92% vs. 83%) than standard PET/CT.

CONCLUSIONS

We support a personalized imaging algorithm for pHPT, placing [18F]Fluorocholine PET/CT at the forefront, followed by 4D-CT integrated into PET/4D-CT in the same imaging session for negative/inconclusive results. When PET/CT results are clearly positive, the additional sensitivity benefit of 4D-CT is minimal.

Comparison between surgical and non-surgical management of primary hyperparathyroidism during pregnancy: a systematic review

PURPOSE

The management of primary hyperparathyroidism (PHPT) during pregnancy may be surgical or conservative. This study compared adverse outcomes between surgical and non-surgical treatments. Additionally, the study investigated the correlation between serum calcium values and complication rates.

METHODS

A systematic review of retrospective studies, case series, and case reports. Biochemical parameters, interventions, and outcomes of each pregnancy were recorded. The study population comprised two groups: the non-surgical and surgical groups. Adverse outcomes were categorized as maternal, obstetric, or neonatal.

RESULTS

The surgical and non-surgical groups consisted of 163 and 185 patients, respectively. A positive correlation was observed between the mean maternal gestational calcium value and both maternal and obstetric complication. Neonatal complications were more prevalent in patients treated conservatively across all maternal calcium values (p < 0.001). No significant differences were observed in maternal outcomes and overall obstetric outcomes between the study groups, albeit a higher mean serum calcium value in the surgical group (12.3 mg/dL) compared with the non-surgical group (11.1 mg/dL).

CONCLUSIONS

Given the significantly lower neonatal adverse outcomes in the surgical group compared to the non-surgical group, along with non-inferior maternal and obstetric outcomes in the surgical group, the overall data of this study suggest that parathyroidectomy is favorable to non-surgical management even in cases of mild hypercalcemia.

Impact of perioperative diagnostic tools on clinical outcomes and cost-effectiveness in parathyroid surgery: a decision model-based analysis

OBJECTIVES

Preoperative and intraoperative diagnostic tools influence the surgical management of primary hyperparathyroidism (PHPT), whereby their performance of classification varies considerably for the two common causes of PHPT: solitary adenomas and multiglandular disease. A consensus on the use of such diagnostic tools for optimal perioperative management of all PHPT patients has not been reached.

DESIGN

A decision tree model was constructed to estimate and compare the clinical outcomes and the cost-effectiveness of preoperative imaging modalities and intraoperative parathyroid hormone (ioPTH) monitoring criteria in a 21-year time horizon with a 3% discount rate. The robustness of the model was assessed by conducting a one-way sensitivity analysis and probabilistic uncertainty analysis.

SETTING

The US healthcare system.

POPULATION

A hypothetical population consisting of 5000 patients with sporadic, symptomatic or asymptomatic PHPT.

INTERVENTIONS

Preoperative and intraoperative diagnostic modalities for parathyroidectomy.

MAIN OUTCOME MEASURES

Costs, quality-adjusted life-years (QALYs), net monetary benefits (NMBs) and clinical outcomes.

RESULTS

In the base-case analysis, four-dimensional (4D) CT was the least expensive strategy with US$10 276 and 15.333 QALYs. Ultrasound and 99mTc-Sestamibi single-photon-emission CT/CT were both dominated strategies while 18F-fluorocholine positron emission tomography was cost-effective with an NMB of US$416 considering a willingness to pay a threshold of US$95 958. The application of ioPTH monitoring with the Vienna criterion decreased the rate of reoperations from 10.50 to 0.58 per 1000 patients compared to not using ioPTH monitoring. Due to an increased rate of bilateral neck explorations from 257.45 to 347.45 per 1000 patients, it was not cost-effective.

CONCLUSIONS

4D-CT is the most cost-effective modality for the preoperative localisation of solitary parathyroid adenomas and multiglandular disease. The use of ioPTH monitoring is not cost-effective, but to minimise clinical complications, the Miami criterion should be applied for suspected solitary adenomas and the Vienna criterion for multiglandular disease.

Persistent and recurrent hyperparathyroidism - Attitude

BACKGROUND

Despite parathyroidectomy represents the curative treatment for primary hyperparathyroidism (pHPT) in up to 98% of patients, persistent hyperparathyroidism (perHPT) and recurrent hyperparathyroidism (rHPT) rates are reported in 22% and 10%, respectively. Indications for reoperation must be balanced with the higher risk of postoperative complications. The aim of this review is summarizing the current evidence in terms of preoperative assessment and surgical approach in patients with perHPT and rHPT.

METHODS

Operations for pHPT between 1997 and 2023 in our center were analyzed and patients with perHPT and rPTH at time of referral were included.

RESULTS

Among 1730 parathyroidectomies for pHPT, 85 patients underwent revisional surgery. Eleven and 74 out of these 85 cases were due to perHPT and rHPT, respectively.

CONCLUSIONS

Prior to reoperation, biochemical assessment and localization methods should always be performed to properly plan surgical strategy. Surgical experience represents the primary determinant in achieving effective disease control.

Surgery for nonlocalizing hyperparathyroidism in high volume center

BACKGROUND

Patients with nonlocalizing hyperparathyroidism pose a significant challenge to surgeons when undergoing neck exploration for parathyroidectomy.

METHODS

We evaluated 536 patients that had parathyroidectomy for primary hyperparathyroidism (PHPT) from 2005 to 2018 at a single tertiary academic center, and 155 (29%) had standard nonlocalizing preoperative imaging (negative ultrasound and sestamibi scans).

RESULTS

There were a total of 102 (66%) non-ectopic single adenomas in the nonlocalizing group and 325 (85%) single adenomas in the localizing group. There was no significant difference (p = 0.09) in adenoma quadrant between localizing and nonlocalizing single adenomas, but the most common location in both groups was right inferior. Patients with nonlocalizing scans were more likely to have double adenomas (21% vs. 9%, p < 0.001), ectopic glands (10% vs. 5%, p = 0.052), and multi-gland disease (13% vs. 8%, p = 0.002).

CONCLUSION

Nonlocalizing PHPT patients experienced similar cure and complication rates as localizing PHPT, but required more bilateral explorations and increased operative time.

Ectopic parathyroid adenoma on sternocleidomastoid muscle: a case report

A 54-year-old woman was admitted to the hospital with a left neck mass. Enhanced CT and ultrasound examinations revealed a lesion in the left sternocleidomastoid muscle. The patient undergone right thyroid lobe resection 8 years ago. Interestingly, the lesion on the sternocleidomastoid muscle, along with the left lobe of the patient's thyroid, visually appears to form a displaced and complete thyroid in the early Tc-99m-MIBI parathyroid scintigraphy. Combined with Tc-99m-MIBI scintigraphy and abnormal PTH and blood calcium levels, the consideration was given to the lesion in the sternocleidomastoid muscle as an ectopic parathyroid adenoma. Subsequent surgical pathology confirmed this suspicion.

Relationship between parathyroid adenoma size, weight and histological subtypes with perioperative serum levels

AIMS

This study aims to identify associations between parathyroid adenoma (PTA) characteristics (histology, weight and size) with the change in parathyroid hormone (PTH) and calcium levels.

METHODS

A historical cohort study was conducted on adult patients with solitary PTA removed in the Gold Coast Health Precinct, Australia, between 2017 and 2022.

RESULTS

PTA weight is correlated with the change in day 1 PTH level (r=0.26, p=0.036), the change in day 1 corrected calcium level (r=0.20, p=0.033), and the change in follow-up corrected calcium level (r=0.47, p<0.001). The largest dimension (size) of PTA is also correlated with the change in day 1 PTH (r=0.30, p=0.011) and the change in follow-up corrected calcium level (r=0.40, p<0.001). Adjusted for age and gender, a statistically significant negative correlation was found between day 1 PTH level and adenoma size, resulting in a 0.5% change in size for every percentage change in PTH level (equating to a 5.0% increase in variance explained, p=0.038). Similarly, a negative correlation was identified in day 1 corrected calcium levels and weight, with a 4.7% change in weight for every percentage of change in day 1 corrected calcium level (an increase of 5.6% variance explained, p=0.010). In addition, a negative correlation was identified, where every 3.1% change in size (an increase of 17.4% variance explained, p<0.001) and 7.6% change in weight (an increase of 22.7% variance explained, p<0.001) was seen with every percentage change in follow-up corrected calcium levels. Clear-cell PTA had the most significant percentage fall in day 1 corrected calcium levels compared with other PTA subtypes (p=0.007).

CONCLUSIONS

Preoperative calcium and PTH levels correlate with PTA weight and size. The degree of change in postoperative corrected calcium levels behaved differently in the clear-cell subtype.

4DCT in Discordant Parathyroid Adenoma Scans: Case Series and Meta-Analysis

OBJECTIVE

To evaluate the accuracy of four-dimensional computerized-tomography (4DCT) for localizing parathyroid adenomas (PTAs) in cases with discordant or non-localizing ultrasonography (US) and Technetium-99 sestamibi (MIBI) scans.

DATA SOURCES

Retrospective case series and systematic review.

REVIEW METHODS

A case series and meta-analysis of patients diagnosed with primary hyperparathyroidism and discordant US and MIBI scans who underwent 4DCT prior to surgery. A comprehensive search for all relevant publications in the English literature between December 2006 and March 2022 was conducted for the meta-analysis. Patients undergoing parathyroidectomy between January 2015 and December 2021 were identified from the institutional electronic database for the case series. All studies were analyzed for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 4DCT adenoma localization capabilities.

RESULTS

Thirteen retrospective studies that included 379 patients and one case series that included 37 patients were identified and analyzed. A per-patient analysis revealed sensitivity for lateralization to the correct side (n = 181) ranging from 80% to 100% with a fixed effects model of 89% (95%confidence interval [CI]: 82%-93%) and a PPV for lateralization ranging from 63%-95% with a random effects model of 87% (95% CI: 77%-95%). Sensitivity of localization to the correct quadrant (n = 172) ranged from 53% to 100% with a random effects model of 90.4% (95% CI: 76%-99%), and the PPV for localization ranged from 52% to 100% with a random effects model of 82% (95% CI: 73%-89%).

CONCLUSION

4DCT enhances imaging capabilities of localizing PTAs in cases of discordant or non-localizing US and MIBI scans.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:2198-2205, 2024.

Clinical, Biochemical and Surgical Outcomes of Primary Hyperparathyroidism in the Present Era: A Prospective Study From a Tertiary Care Hospital

Introduction Primary hyperparathyroidism (PHPT) has undergone a considerable change from being symptomatic to asymptomatic. This is the first large study from North India to study the clinical and biochemical features and surgical outcomes in the present era. Study design This is a cross-sectional study that was conducted in the Department of Endocrinology (SKIMS) from February 2021 to December 2022, in which 103 patients diagnosed with PHPT were included. Evaluation included measurement of total calcium, phosphorus, alkaline phosphate, intact parathyroid hormone, 25-hydroxy vitamin, 24-hour urinary calcium, radiological survey of hands and skull, Dual Energy X-ray absorptiometry, and ultrasonography (USG) of the abdomen. USG neck and technetium-99m sestamibi scans were used for preoperative localization; however, in cases of discordance between these investigations or suspicions of multi-glandular disease, four-dimensional computerized tomography of the neck was used. Patients were subjected to surgery according to the guidelines and monitored post-surgery for complications like hypocalcemia and hungry bone syndrome and to document the cure. Results The mean age of patients was 42.8±14.73 years, with a female-to-male ratio of 4.4:1. The mean eGFR of patients was 99.1±30.87 ml/min, with 55 (53.4%) of them having renal disease. Osteoporosis and fractures were present in 41 (39.8%) and 5 (4.8%) patients, respectively. Cholelithiasis and pancreatitis were present in 25 (24.3%) and 5 (4.9%) patients, respectively. Hypertension (HTN) and diabetes mellitus (DM) were the commonest comorbidities, which were present in 34 (33.1%) and 15 (14.5%) patients, respectively. Mean preoperative levels of calcium, phosphorus (PO4), alkaline phosphate (ALP), intact parathyroid hormone (iPTH), 25(OH)vitamin D, and 24-hour urinary calcium were 12.1 mg/dl, 2.35 mg/dl, 210.2 U/L, 332.9 pg/ml, 25.7 ng/ml, and 452.1 mg/day, respectively. The most common type was right inferior parathyroid adenoma, present in 45 cases (43.7%), followed by left inferior parathyroid adenoma in 31 cases (30.1%). A total of 75 patients (72.8%) underwent minimally invasive parathyroidectomy, with 68 patients (90.7%) achieving a biochemical cure. The mean adenoma weight was 3.19±2.25 g. There was no statistically significant correlation (r) between preoperative biochemical parameters and adenoma weight. Conclusion Despite improvements in imaging and the easy availability of immunoassays for early diagnosis, renal disease continued to be the most common presentation, followed by skeletal involvement in our population. In developing countries like India, any patient presenting with nephrolithiasis or nephrocalcinosis, low bone mass, or fragility fractures should be evaluated for PHPT.

Fine needle aspiration biopsy of parathyroid; is it meaningful? A cytologic study of 81 cases with histological and clinical correlations

BACKGROUND

Recognizing the parathyroid gland and distinguishing the parathyroid from thyroid lesions in fine needle aspiration (FNA) is challenging. This study aimed to identify cytomorphologic features suggestive of parathyroid origin and to assess the utility of cytopathology in conjunction with ancillary tests in the identification of parathyroid glands.

MATERIALS AND METHODS

Ultrasound (US) guided FNA of parathyroid gland and lesions in 81 patients were reviewed concerning clinical history and correlated to histopathologic findings in available cases. FNA smears were evaluated for cellularity, architectural patterns, cellular and nuclear features, and background of the smears. In 78 cases, FNA was supplemented by a measurement of parathormone (PTH) levels in the needle washout fluid (FNA-PTH assay) and/or GATA3/PTH/chromogranin-A immunostainings.

RESULTS

Sixty-four cases were diagnosed cytologically as parathyroid lesions in conjunction with FNA-PTH assay and/or immunocytochemical examinations. In an additional nine cases, a diagnosis of parathyroid lesions was rendered after repeated FNA with FNA-PTH assay. The histolopathologic diagnosis of surgically excised cases (n = 75) included parathyroid adenoma (60 cases), atypical parathyroid adenoma (4 cases), parathyroid hyperplasia (10 cases), and parathyroid carcinoma (1 case). Major cytological findings of parathyroid tissue included high cellularity, scattered naked nuclei, cribriform and three-dimensional clusters, stippled chromatin, and oxyphilic cytoplasm while papillary pattern or colloid-like material was identified in three cases respectively. No nuclear grooves or inclusions were seen in any case.

CONCLUSIONS

High cellularity scattered naked nuclei, cribriform and three-dimensional patterns, stippled chromatin and oxyphilic cytoplasm are cytomorphologic features that favour parathyroid origin. A combination of these features with FNA-PTH assay and/or GATA3, PTH, and chromogranin-A immunostainings on cytologic specimens aid in the identification of parathyroid glands and the distinguishing of parathyroid from thyroid lesions.

Intraoperative parathyroid hormone measurement pitfalls: parathyroid hormone spikes with carboxyl-terminal parathyroid hormone fragments in primary hyperparathyroidism-a case report

BACKGROUND

Intraoperative parathyroid hormone (IOPTH) monitoring is a critical surgical adjunct for determining the extent of surgery for primary hyperparathyroidism (PHPT), with reported false-positive and false-negative rates of up to 10%. Surgeons must understand the parathyroid hormone (PTH) dynamics and select the appropriate IOPTH protocol and interpretation criteria for curative surgery.

CASE PRESENTATION

We present the case of a 64-year-old woman with a large cystic parathyroid tumor and PHPT who experienced a significant delay in IOPTH decrease but was cured without additional surgery. The patient's basal intact PTH was 96.2 pg/mL, which decreased to 93.3 pg/mL at 25 min and 72.4 pg/mL at 55 min after removal of the parathyroid tumor. In an attempt to elucidate its pathophysiology, 1-84 PTH levels were measured in stored serum. These results can also be attributed to the relatively low basal PTH levels, intact PTH spike, and high ratio of large carboxyl-terminal PTH fragments present. The patient had normal intact PTH and calcium levels at the 9-month postoperative visit.

CONCLUSIONS

As detailed reports on these phenomena are scarce, we discuss the causes of false-negative IOPTH results in terms of PTH production, secretion, metabolism, and differences in measurement methods to avoid unnecessary surgery.

Cervicomediastinal Hematoma: Atypical Presentation of a Parathyroid Carcinoma

Parathyroid carcinoma (PC) is a rare endocrine neoplasm that typically presents with osteopenia/osteoporosis, nephrolithiasis, asthenia, and neuropsychiatric symptoms. We describe the case of a 48-year-old woman, presenting with a large painful hematoma in the cervicomediastinal area. The neck ultrasound (US) demonstrated a solid lesion measuring 40 × 80 × 55 mm, markedly hypoechoic, which extended from the right thyroid lobe to the mediastinum. The blood tests showed elevated serum calcium and parathyroid hormone (PTH) concentrations, consistent with hypercalcemic primary hyperparathyroidism. The patient was rehydrated and treated with furosemide, cholecalciferol, and bisphosphonate, and underwent right lower parathyroidectomy, right hemithyroidectomy, and lymphadenectomy of the right VI cervical level. Histological examination was diagnostic for nonangioinvasive or neuroinvasive PC, and the thyroid lobe was the site of lymphocytic thyroiditis; all removed lymph nodes were benign. The postoperative course was regular. Postoperative neck US showed a hypoechoic left thyroid lobe without evidence of residual neoplasm in the right thyroid bed. Levothyroxine therapy of 50 mcg/day was started because of serum thyrotropin concentrations elevated at 18 mcIU/mL (normal reference range, 0.35-4.0 mIU/mL). Eight years after diagnosis, the patient is in good general condition, with no clinical, biochemical, or imaging evidence of disease persistence/recurrence.

Four-Dimensional Computed Tomography for Parathyroid Adenoma Localization: A Pre-Operative Imaging Protocol

OBJECTIVE

Primary hyperparathyroidism (PHPT) affects approximately 0.86% of the population, with surgical resection as the treatment of choice. A 4D computed tomography (CT) is a highly effective tool in localizing parathyroid adenomas; however, there is currently no defined role for 4D CT when stratified against ultrasonography (USG) and nuclear medicine Technetium Sestamibi SPECT/CT (SES) imaging.

STUDY DESIGN

Retrospective Study.

SETTING

University Hospital.

METHODS

All patients who underwent parathyroidectomy for PHPT between 2014 and 2019 at a single institution were reviewed. Patients who had a 4D CT were included. We compared outcomes of 4D CT as a second line imaging modality to those of USG and SES as first line modalities. An imaging algorithm was proposed based on these findings.

RESULTS

There were 84 patients identified who had a 4D CT after unsuccessful first line imaging. A 4D CT localized parathyroid adenoma to the correct quadrant in 64% of cases, and to the correct laterality in 75% of cases. Obese patients had significantly lower rates of adenoma localization with USG (33.4%), compared to non-obese patients (67.5%; P = .006). In determining multigland disease the sensitivity of 4D CT was 86%, while the specificity was 87%.

CONCLUSIONS

A 4D CT has impressive rates of accurate localization of parathyroid adenomas; however due to the radiation exposure involved, it should remain a second line imaging modality. PHPT patients should first be evaluated with USG, with 4D CT used if this is unsuccessful and patients are greater than 40 years old, have a high BMI, or are having revision surgery.

A case report of primary hyperparathyroidism in an adolescent during Ramadan fast

Primary hyperparathyroidism is rare in children and usually presents with nonspecific symptoms. Ramadan fasting has been reported to unmask the diagnosis of primary hyperparathyroidism. A 15-year-old boy presented to the clinic for an emergency department follow up visit. He had started Ramadan fasting a week before his presentation to the clinic. He reported unintentional weight loss, abdominal pain, constipation, frequent headaches, exercise intolerance, tiredness, and palpitations. Physical examination was unremarkable except that he looked tired. Investigations revealed elevated calcium and parathyroid hormone, hypophosphatemia, low vitamin D, and parathyroid adenoma. He underwent parathyroidectomy, leading to a decrease in parathyroid hormone levels. He did well postoperatively, and by his 11-month follow-up visit, his calcium was back to a normal level, he was energetic, and had gained weight. A high index of suspicion is required to diagnose primary hyperparathyroidism in young patients, especially young Ramadan-fasting patients, who mostly present with vague nonspecific symptoms.

The Parathyroid Gland: An Overall Review of the Hidden Organ for Radiologists

Parathyroid glands are small endocrine glands that regulate calcium metabolism by producing parathyroid hormone (PTH). These are located at the back of the thyroid gland. Typically, four glands comprise the parathyroid glands, although their numbers may vary among individuals. Parathyroid diseases are related to parathyroid gland dysfunction and can be caused by problems with the parathyroid gland itself or abnormal serum calcium levels arising from renal disease. In recent years, as comprehensive health checkups have become more common, abnormal serum calcium levels are often found incidentally in blood tests, after which several additional tests, including a PTH test, ultrasonography (US), technetium-99m sestamibi parathyroid scan, single-photon-emission CT (SPECT)/CT, four-dimensional CT (4D-CT), and PET/CT, are performed for further evaluation. However, the parathyroid gland remains an organ less familiar to radiologists. Therefore, the normal anatomy, pathophysiology, imaging, and clinical findings of the parathyroid gland and its associated diseases are discussed here.

Head-to-head comparison of [11C]methionine PET, [11C]choline PET, and 4-dimensional CT as second-line scans for detection of parathyroid adenomas in primary hyperparathyroidism

PURPOSE

Accurate preoperative localization is imperative to guide surgery in primary hyperparathyroidism (pHPT). It remains unclear which second-line imaging technique is most effective after negative first-line imaging. In this study, we compare the diagnostic effectiveness of [11C]methionine PET/CT, [11C]choline PET/CT, and four dimensional (4D)-CT head-to-head in patients with pHPT, to explore which of these imaging techniques to use as a second-line scan.

METHODS

We conducted a powered, prospective, blinded cohort study in patients with biochemically proven pHPT and prior negative or discordant first-line imaging consisting of ultrasonography and 99mTc-sestamibi. All patients underwent [11C]methionine PET/CT, [11C]choline PET/CT, and 4D-CT. At first, all scans were interpreted by a nuclear medicine physician, and a radiologist who were blinded from patient data and all imaging results. Next, a non-blinded scan reading was performed. The scan results were correlated with surgical and histopathological findings. Serum calcium values at least 6 months after surgery were used as gold standard for curation of HPT.

RESULTS

A total of 32 patients were included in the study. With blinded evaluation, [11C]choline PET/CT was positive in 28 patients (88%), [11C]methionine PET/CT in 23 (72%), and 4D-CT in 15 patients (47%), respectively. In total, 30 patients have undergone surgery and 32 parathyroid lesions were histologically confirmed as parathyroid adenomas. Based on the blinded evaluation, lesion-based sensitivity of [11C]choline PET/CT, [11C]methionine PET/CT, and 4D-CT was respectively 85%, 67%, and 39%. The sensitivity of [11C]choline PET/CT differed significantly from that of [11C]methionine PET/CT and 4D-CT (p = 0.031 and p < 0.0005, respectively).

CONCLUSION

In the setting of pHPT with negative first-line imaging, [11C]choline PET/CT is superior to [11C]methionine PET/CT and 4D-CT in localizing parathyroid adenomas, allowing correct localization in 85% of adenomas. Further studies are needed to determine cost-benefit and efficacy of these scans, including the timing of these scans as first- or second-line imaging techniques.

Pearls of Parathyroidectomy: How to Find the Hard to Find Ones

The treatment of hyperparathyroidism through parathyroidectomy requires careful and complete preoperative evaluation. There are multiple imaging modalities and methods available to clinicians today to aid in identifying a pathological lesion; however, each has limitations that the clinician must understand. A systematic approach to patient evaluation, imaging, and surgical exploration is necessary to ensure accurate diagnosis and maximize the chances of minimally invasive and successful surgical removal.

Parathyroid Carcinoma in a Patient With Secondary Hyperparathyroidism and Thyroid Hemiagenesis: A Case Report and Review of the Literature

Parathyroid carcinoma is a rare endocrine tumor. Parathyroid carcinoma in patients with secondary hyperparathyroidism due to chronic kidney disease is also rare. In addition, thyroid hemiagenesis is a rare congenital anomaly. We report an extremely rare case of parathyroid carcinoma in a patient with secondary hyperparathyroidism and thyroid hemiagenesis. We also present a review of the literature of this rare entity. We also discuss the surgical procedure performed for this patient. Our review of the literature found 34 case reports of parathyroid carcinoma in patients undergoing dialysis due to chronic renal failure; 14 reports of thyroid hemiagenesis with parathyroid disease; and no previous reports of thyroid hemiagenesis with secondary hyperparathyroidism and parathyroid carcinoma. Although surgical treatment of parathyroid carcinoma requires combined resection with the thyroid, peritracheal dissection with total parathyroidectomy, and monitoring intact parathyroid hormone as a tumor marker, our procedure preserved the patient's thyroid function. There has been no evidence of recurrence for over 8 years.

Massive 4-Gland Parathyroid Hyperplasia Initially Detected as a Parathyroid Adenoma

Parathyroid adenoma (PA) and parathyroid hyperplasia (PH) are common causes of primary hyperparathyroidism (PHPT), for which the only definitive treatment is surgery. Abnormalities in the parathyroid glands can be identified with various imaging modalities including ultrasound (US), sestamibi scan (MIBI), 4-dimensional computed tomography (4D-CT), and positron emission tomography/computed tomography (PET/CT). While it is not uncommon for parathyroid pathology to be undetected on imaging, this is more typical of low-volume hyperplasia and smaller-sized adenomas. We present the case of a 65-year-old man with PHPT who initially had a solitary parathyroid mass detected by US, but who was ultimately discovered to have massive PH with hyperplastic glands not visualized on US or MIBI. This atypical presentation may help guide providers in decisions on ordering and interpreting various imaging modalities for patients with PHPT. In this case, 4D-CT was the only modality in which large hyperplastic glands were identified, suggesting superior sensitivity. This case also highlights the importance of intraoperative parathyroid hormone testing to aid in diagnostic prediction.

Diagnostic Performance of Magnetic Resonance Imaging for Parathyroid Localization of Primary Hyperparathyroidism: A Systematic Review

Accurate preoperative localization is crucial for successful minimally invasive parathyroidectomy in primary hyperparathyroidism (PHPT). Preoperative localization can be challenging in patients with recurrent and/or multigland disease (MGD). This has led clinicians to investigate multiple imaging techniques, most of which are associated with radiation exposure. Magnetic resonance imaging (MRI) offers ionizing radiation-free and accurate imaging, making it an attractive alternative imaging modality. The objective of this systematic review is to provide an overview of the diagnostic performance of MRI in the localization of PHPT. PubMed and Embase libraries were searched from 1 January 2000 to 31 March 2023. Studies were included that investigated MRI techniques for the localization of PHPT. The exclusion criteria were (1) secondary/tertiary hyperparathyroidism, (2) studies that provided no diagnostic performance values, (3) studies published before 2000, and (4) studies using 0.5 Tesla MRI scanners. Twenty-four articles were included in the systematic review, with a total of 1127 patients with PHPT. In 14 studies investigating conventional MRI for PHPT localization, sensitivities varied between 39.1% and 94.3%. When employing more advanced MRI protocols like 4D MRI for PHPT localization in 11 studies, sensitivities ranged from 55.6% to 100%. The combination of MR imaging with functional techniques such as 18F-FCH-PET/MRI yielded the highest diagnostic accuracy, with sensitivities ranging from 84.2% to 100% in five studies. Despite the limitations of the available evidence, the results of this review indicate that the combination of MR imaging with functional imaging techniques such as 18F-FCH-PET/MRI yielded the highest diagnostic accuracy. Further research on emerging MR imaging modalities, such as 4D MRI and PET/MRI, is warranted, as MRI exposes patients to minimal or no ionizing radiation compared to other imaging modalities.

Approach to the Patient With Parathyroid Carcinoma

Parathyroid carcinoma (PC) is usually associated with severe symptomatic primary hyperparathyroidism (PHPT) and accounts for less than 1% of all cases of PHPT and approximately 0.005% of all cancers. PC most commonly occurs as a sporadic disease and somatic CDC73 mutations can be detected in up to 80% of cases. Approximately 30% of patients harbor a germline mutation of the CDC73 gene. Preoperative diagnosis of PC is difficult because no disease-specific markers are available, and PC should be suspected in patients with severe hypercalcemia and end-organ complications. The diagnosis is based on the evidence of invasive tumor growth at histology and/or metastases. En bloc resection of the tumor, together with the ipsilateral thyroid lobe and adjacent structures, should be performed by an experienced surgeon when PC is suspected. This surgical approach reduces the risk of recurrence and metastasis and offers the highest chance of cure. Nonetheless, PC has a recurrence rate of 40% to 60% and, if feasible, multiple surgical procedures should be performed. When surgery is no longer an option, medical treatment is aimed to reduce hypercalcemia and target organ complications. Targeted agents have been effectively used in a few cases. We describe herein a patient with severe PHPT due to PC and provide a systematic diagnostic and treatment approach. A thorough review of the medical history, a typical clinical and biochemical phenotype and, in some cases, the revision of the histological examination provide the clues for the diagnosis of PC.

Invasive Testing for Preoperative Localization of Parathyroid Tumors

Context

The identification of parathyroid tumor(s) in patients with persistent/recurrent primary hyperparathyroidism (PHPT) is critical for a successful reoperative surgery. If noninvasive studies (ultrasound, computed tomography, magnetic resonance imaging, sestamibi) fail to conclusively localize the tumor, invasive procedures (arteriography and selective venous sampling) are performed.

Objective

To describe our experience with invasive studies for parathyroid tumor localization and provide follow-up data on selective arterial hypocalcemic stimulation with central venous sampling, a technique developed at our center.

Methods

We identified patients who underwent preoperative invasive testing for localization of parathyroid tumor from 1991 to 2020. The result of each invasive localization study [arteriogram, hypocalcemic stimulation and selective venous sampling (SVS)] was categorized as true-positive, false-positive, and false-negative based on histology and biochemical outcome.

Results

Ninety-four patients with 96 tumor occurrences underwent invasive testing for parathyroid tumor localization. Arteriogram, hypocalcemic stimulation, and SVS accurately localized the tumor in 47 of 94 (50%), 56 of 93 (60%), and 51 of 62 (82%) tumors, respectively. Hypocalcemic stimulation was more likely to correctly localize the tumor when arteriogram showed a blush [37 of 50 (74%) vs 19 of 43 (44%), P = .01]. When both arteriogram and hypocalcemic stimulation yielded concordant positive findings, SVS did not change management in the 18 cases in which all 3 were performed. Twelve patients remained with persistent PHPT; all had recurrent disease with multiple affected glands.

Conclusion

Hypocalcemic stimulation is a useful adjunct in patients with PHPT who require invasive localization and can obviate the need for SVS. Clinical Trial number: NCT04969926.

Simultaneous Bilateral Quadriceps Tendon Rupture Secondary to Parathyroid Carcinoma: A Case Report

Simultaneous bilateral quadriceps tendon ruptures are a rare occurrence commonly associated with a traumatic event or systemic disease. A 31-year-old man presented with simultaneous bilateral quadriceps tendon ruptures with associated hyperparathyroidism secondary to parathyroid carcinoma. The injury occurred after the patient attempted to lift a small wooden log from the ground. We discussed the multidisciplinary management of this patient resulting in bilateral quadriceps tendon repairs, tumor resection, and oncological and endocrinological restoration. Clinical follow-up is reported at 15 years after surgery. Parathyroid carcinoma is an extremely rare cancer and rarely the cause of hyperparathyroidism. The systemic effects of the tumor eventually lead to the rupturing of both quadriceps tendons. Orthopaedic physicians must remain vigilant in identifying the root cause of injuries that are atypical in nature.

Oligometastatic Parathyroid Carcinoma Presenting as Neck Pain: A Case Report

BACKGROUND

Parathyroid carcinoma (PC) is an exceedingly rare, slow-growing but progressive endocrine malignancy that represents a diagnostic and therapeutic challenge. Vertebral metastasis of PC is remarkable, with only 3 prior cases of spinal metastasis reported in the literature.

CASE DESCRIPTION

A 62-year-old woman presented with 1 week of neck pain radiating down her right arm. Cervical x-ray revealed a lytic lesion of the C4 vertebral body. Lab work revealed hypercalcemia with an elevated parathyroid hormone level. Computed tomography and magnetic resonance imaging revealed frank destruction of the C4 vertebral body and pedicles by PC. She was treated with corpectomy, mass excision, anterior cervical discectomy and fusion, postoperative radiotherapy, and nonspecific inhibitors of active tumor pathways. Her symptoms resolved postoperatively, and she has remained negative for reoccurrence at 15-month follow-up.

CONCLUSIONS

To the authors' knowledge, we report the first described cervical spine metastasis of PC. Additionally, we review the treatment of this rare neoplasm in an extremely rare location in the age of tumor sequencing and morphoproteomic analysis.

The evolution of primary hyperparathyroidism publications and global productivity from past to present: A bibliometric analysis during 1980 to 2022

The aim of this study was to perform a descriptive analysis of scientific articles about primary hyperparathyroidism (PHPT) using bibliometric approaches. By analyzing the links between the various research components (authors, journals, institutions, countries) of the academic outputs, it was aimed to summarize the intellectual structure of PHPT, identify recent research trends, and determine the global productivity. Three thousand nine hundred fifty-four articles on PHPT published between 1980 and 2022 were pulled from the Web of Science database and analyzed using bibliometric approaches. Bibliometric network visualization maps were used to identify trending topics, citation analysis, and international collaborations. Spearman correlation coefficient was used for correlation analysis. The 3 most prolific authors are Bilezikian JP. (n = 87), Silverberg SJ. (n = 72) and Akerstrom G. (n = 57). The top 3 most productive institutions were Columbia University (n = 133), Udice French Research Universities (n = 127) and Uppsala University (n = 98). The top 3 most productive journals were Surgery (n = 216), Journal of Clinical Endocrinology and Metabolism (n = 201) and World Journal of Surgery (n = 148). The top 3 contributing countries to the PHPT literature were United States of America (n = 1062, 26.8%), Italy (346, 8.7%) and United Kingdom (274, 6.9%). The most studied topics from past to present are parathyroidectomy, hypercalcemia, parathyroid hormone/adenoma/glands, calcium/calcimimetics, scintigraphy/sestamibi, bone mineral density, ultrasound, vitamin D, osteoporosis, minimally invasive parathyroidectomy, brown tumor, nephrocalcinosis/nephrolithiasis, multiple endocrine neoplasia type 1, normocalcemia, pregnancy, imaging/preoperative imaging, parathyroid cancer/carcinoma, asymptomatic primary hyperparathyroidism, and cinacalcet. The trending topics in recent years were normocalcemic primary hyperparathyroidism, trabecular bone score, children, CDC73, microwave ablation, radiofrequency ablation, denosumab, cinacalcet, preoperative imaging, imaging, diagnosis, CT, PET, PET/CT, 4D/CT, SPECT/CT, F-18-fluorocholine, quality of life, fractures, and metabolic syndrome. We can say that there will be an increasing research trend on PHPT in the coming years. In addition to the Western countries such as the United States and European countries with large economies, Japan and Turkey were also identified as leading countries in the development of the PHPT literature. This study provides significant information about the intellectual structure and global productivity of PHPT to clinicians and other researchers interested on PHPT.

Tissue Parathyroid Hormone Washout: A Reliable Method for the Localization and Exclusion of Parathyroid Adenomas

Background and objective Accurate identification of parathyroid adenoma (PA) is essential for minimally invasive treatment of primary hyperparathyroidism (PHPT). The aim of this study is to evaluate the results of parathyroid hormone (PTH) assay in aspirates of suspicious neck lesions and to clarify its reliability in determining whether the lesion is of parathyroid origin. Methods A total of 134 lesions (104 imaging-suspected PA and 30 concomitant thyroid nodules as a control group) of 101 patients were retrospectively analyzed. Patients with positive, negative, or never scintigraphy were included in our study. Ultrasound (US) was performed again and US-guided tissue fine needle aspiration with PTH washout (PTH-WO) was performed from suspicious lesions. A PTH-WO level higher than the patient's serum PTH levels is proposed for a positive test, and a PTH-WO level lower than the upper limit of the laboratory PTH level is proposed for a negative test. A definitive diagnosis was made postoperatively histopathologically. Results PTH-WO levels (median (IQR)) were significantly higher in the positive group (n = 93, 5000 (1600) ng/L) compared to the negative group (n = 11, 17 (13.1) ng/L) and thyroid nodule aspirate group (n = 30, 14 (4.3) ng/L) (p < 0.001). Among 93 PTH-WO-positive lesions, 42 lesions (45.1%) were not identified by parathyroid scintigraphy (PS), 20 (21.5%) lesions were suspiciously PS, and 33 lesions (35.4%) were negative or suspicious by first US findings. Of the 93 patients localized with PTH-WO, two were cystic PAs ablated by aspiration. The final pathology result of 91 operated patients proved PA. The sensitivity, specificity, negative predictive value, and positive predictive value of the PTH-WO were observed as 1.00, 0.82, 0.09, and 0.91, respectively. Conclusion Comprehensive repeated US and PTH-WO from the lesion increase the accurate localization of PAs. PTH-WO is a highly reliable method for differentiating parathyroid lesions from other cervical lesions.

Primary hyperparathyroidism: clinical manifestations, diagnosis and evaluation according to the Fifth International Workshop guidelines

Primary hyperparathyroidism (PHPT) is a frequent endocrine disease which mainly affects the skeletal system and kidney. Some of its signs and symptoms are similar to those seen in rheumatic diseases such as rheumatoid arthritis, Sjögren's disease, fibromyalgia, polymyalgia rheumatica, gout or systemic lupus erythematosus. Coexistence of primary hyperparathyroidism with those pathologies potentiate their effects on muscles, bones and joints, increasing the risk of complications such as osteoporosis and fractures. Therefore, rheumatologists should be familiar with symptoms and diagnostic criteria of PHPT and consider it in the differential diagnosis of rheumatic diseases. In 2022 the Fifth International Workshop guidelines on the PHPT evaluation and management were published. They are based on a profound analysis of advances in research concerning multiple fields, that include genetics, outcomes and new imaging modalities of PHPT. They have led to revision of previous renal indications for parathyroidectomy in PHPT. There is also more evidence for the other recommendations regarding evaluation of the disease. This article summarizes the most relevant elements of these recommendations and refers them to Polish realities. I focus on the symptoms of primary hyperparathyroidism and its diagnosis as I consider these areas to be the most important for non-endocrinologists.

Robot-Assisted Parathyroidectomy Using Indocyanine Green (ICG) Fluorescence in Primary Hyperparathyroidism

Background and Objectives: Surgical treatment for primary hyperparathyroidism (PHPT) has evolved from bilateral exploration through a long transcervical incision to focused parathyroidectomy with a minimal incision above the pathologic gland. Recently, endoscopic or robot-assisted parathyroid surgery without direct neck incision has been introduced. The aim of this study was to investigate the effectiveness of indocyanine green (ICG) fluorescence as a new method for the visual identification of abnormal hyperfunctioning parathyroid glands in robot-assisted parathyroidectomy using FireflyTM technology. We also aimed to conduct a comparative analysis between robot-assisted parathyroidectomy and conventional focused parathyroidectomy in order to identify clinical differences between the two surgical approaches. Materials and Methods: A total of 37 patients with PHPT underwent parathyroidectomy at a single university hospital between September 2018 and December 2022. Thirty-one patients underwent open focused parathyroidectomy (open group), and six patients underwent robot-assisted parathyroidectomy (robot group). Pre-operative localization via parathyroid SPECT-CT and an intraoperative parathyroid hormone (IOPTH) assay were used to successfully remove the pathologic parathyroid in both groups. ICG was administered only in the robot group. Results: Pathologic parathyroid showed a persistent fluorescence pattern under near-infrared vision. After the removal of the fluorescent parathyroid gland, IOPTH was normalized in all six patients in the robot group. However, the open group showed shorter hospital stays (1.8 ± 1.2 vs. 3.0 ± 0.0 days, p < 0.001) and shorter operation times (91.1 ± 69.1 vs. 152.5 ± 23.6 min, p = 0.001) than the robot group. After 6 months of surgery, PTH, calcium, and ionized calcium levels were all normalized without significant differences between the groups. Conclusions: Robot-assisted parathyroidectomy using ICG is helpful for the visual identification of the pathologic parathyroid gland. The advantage of robot parathyroidectomy is a better cosmetic outcome. However, it still does not show better clinical outcomes than conventional open focused parathyroidectomy.

Severe hypercalcemia secondary to parathyroid adenoma: Series of four consecutive cases at a tertiary care hospital in Qatar

INTRODUCTION

In most cases of parathyroid adenoma (PA), it is not palpable and physical examination shows no remarkable findings. Hence diagnosis requires an index of suspicion. The current paper describes four cases of severe hypercalcemia secondary to PA.

PRESENTATION OF CASES

Case 1 - 29 years old Sudanese female with history of nausea/vomiting, fatigue, loss of appetite and bone aches. She had large palpable left lower neck swelling, and high calcium and PTH. Ultrasound (US) neck and SPECT/CT scan after sestamibi injection showed left inferior PA. Case 2-73 years old Sudanese male referred with history of abdominal pain and flatulence. He had severely high calcium, elevated parathormone (PTH), and high 24-hour urine calcium. US and SPECT/CT showed a left inferior PA. Case 3-54 years old Bangladeshi male, referred with history of renal colic/urolithiasis. Laboratory results showed severely high calcium and PTH levels. US and SPECT/CT scan showed right inferior PA. Case 4-35 years old Tunisian female, 12 weeks pregnant, referred with recurrent nausea and vomiting of increasing frequency from the second week of pregnancy. Laboratory tests revealed severe hypercalcemia and high PTH. US showed two parathyroid lesions.

DISCUSSION

The patients were admitted as emergency cases and investigations diagnosed severe hypercalcemia secondary to PA. All patients underwent neck exploration and PA excision. Histology confirmed PA. The four cases were swiftly assessed and treated before progressing into the more serious hypercalcemic crisis which can lead to grave consequences, particularly in the case of the pregnant female. All patients recovered with no complications and were clinically well with normal calcium level on follow up.

CONCLUSION

Severe hypercalcemia must be swiftly and thoroughly assessed to prevent the more serious hypercalcemic crisis. Clinicians need to be suspicious of parathyroid adenoma as a probable cause. Severe hypercalcemia is often accompanied with vomiting, and in pregnant females, this could be mistaken for hyperemesis gravidarum. Excision of the parathyroid adenoma treats the condition and follow up of serum calcium and PTH confirms the favorable outcome of surgery.

Parathyroid carcinoma: Current management and outcomes – A systematic review

OBJECTIVE

Parathyroid carcinoma is rarely encountered in clinical practice. When faced with this clinical challenge, there is currently a paucity of evidence available for the optimal management of patients with parathyroid carcinoma. This systematic review synthesizes the available literature to evaluate the optimal management approach, thus providing guidance for future management.

METHODS

A systematic review was conducted according to PRISMA guidelines using Ovid MEDLINE, EMBASE, and PubMed databases for studies, published in English, reporting on parathyroid carcinoma. Full text of potentially eligible articles were reviewed by two authors independently and eligible studies selected. Treatment options and associated outcomes were evaluated. Descriptive statistics were used to describe pooled patient cohorts.

RESULTS

3203 articles were initially identified using the search criteria with 59 full-text articles then screened for eligibility. Seven articles, all retrospective studies, concerning 2307 patients (median 224/study). Parathyroidectomy alone was the most frequently utilised surgical approach across all studies, followed by en-bloc resection (with adjacent thyroid and/or nodal tissue). There was no difference in post-operative morbidity, mortality or survival between surgical approaches (p < 0.005). Patients who underwent either form of surgery had longer overall survival than those managed non-operatively (p < 0.005).

CONCLUSION

Surgical resection is the optimal treatment of parathyroid carcinoma. However there remains no consensus on the optimal extent of surgery, and as such future randomised prospective studies are necessary to evaluate the effects of different surgical approaches on morbidity, mortality and oncologic outcomes. Following resection, long-term surveillance with PTH is advised.

A parathyroid cancer with soporous state, depression, and severe cognitive decline in acute renal failure

Key Clinical Message

Soporous state in acute renal failure represent an atypical presentation of parathyroid cancer. Complete prompt investigations and diagnosis have a fundamental role in the management of this disease.

Abstract

This report describes a case of parathyroid carcinoma (PC) with an uncommon first clinical presentation: soporous state, depression, and severe cognitive decline in association with acute renal failure. After discovering extremely high serum calcium and parathyroid hormone (PTH) levels, the diagnosis of primary hyperparathyroidism (pHPT) was made and a surgical en bloc resection was performed. After the surgical intervention, the histological examination revealed the presence of a malignant parathyroid disease, thus confirming our first preoperative suspicion.

Mediastinal Intrathymic Parathyroid Adenoma: A Case Report and Review of the Literature

The classic clinical vignette of primary hyperparathyroidism is well described as "bones, stones, abdominal moans, and psychiatric overtones" to reflect the effects of excess parathyroid hormone (PTH) and calcium. Most commonly, primary hyperparathyroidism is due to a functional parathyroid adenoma situated by the thyroid gland. Rarely, the primary focus of autonomously produced PTH is located ectopically within the mediastinum. A 19-year-old Caucasian female with no relevant past medical history presented to the emergency department with tachycardia, nausea, vomiting, and a five-day history of vague, mid-abdominal pain. Initial computed tomography (CT) with contrast of the abdomen and pelvis was negative for acute findings, and she subsequently underwent biochemical screening. The patient was found to have elevated serum calcium and PTH, raising suspicion for the diagnosis of primary hyperparathyroidism. Further evaluation for a parathyroid adenoma was negative by a CT scan of the neck and thyroid ultrasound. A nuclear medicine parathyroid single-photon emission computed tomography (SPECT)/CT with technetium (Tc) 99m sestamibi found an abnormal nodular uptake within the left prevascular mediastinum suggestive of an ectopic parathyroid adenoma. A left-sided, video-assisted thoracoscopic surgery (VATS) with successful excision of the ectopic mediastinal parathyroid adenoma was performed. Surgical pathology revealed that the parathyroid adenoma was completely excised and surrounded by thymus and adipose tissue. The patient tolerated the procedure well and was discharged without further complications. The rarity of mediastinal, intrathymic parathyroid adenomas resulted in delayed diagnosis in this patient, understandably so as errant embryogenesis does not occur commonly. Visualization with SPECT/CT and successful specimen excision by minimally invasive VATS resulted in the accurate diagnosis and ultimate cure of this patient's primary hyperparathyroidism.

Feasibility and Performance of Free-Hand Single-Photon Computed Tomography/Ultrasonography for Preoperative Parathyroid Adenoma Localization: A Pilot Study

The aim of this prospective pilot study was to evaluate the feasibility of a new hybrid imaging modality, free-hand single-photon computed tomography/ultrasonography (fhSPECT/US), for preoperative localization of parathyroid adenomas and to compare its performance with conventional ultrasonography and SPECT/CT. Twelve patients diagnosed with primary hyperparathyroidism underwent sequentially US and parathyroid scintigraphy, including SPECT/CT, followed by fhSPECT/US, allowing for real-time fusion between US and freehand-generated gamma-camera images. The fhSPECT/US detection rates were correlated with histopathology, when available, or with the imaging modality showing the most lesions. Based on a per patient analysis, the detection rate was significantly different when comparing SPECT/CT to fhSPECT/US (p = 0.03), and not significantly different when comparing SPECT/CT to US (p = 0.16) and US to fhSPECT/US (p = 0.08). Based on a per-lesion analysis, the detection rate of SPECT/CT was significantly higher than that of US (p = 0.01) and fhSEPCT/US (p = 0.003), and there was no significant difference in detection rate when comparing US to fhSPECT/US (p = 0.08). The main perceived limitations of fhSPECT/US in lesion detection were: (i) lesions localized at a depth ≥4.5 cm; (ii) imperfect image fusion due to tissue compression; (iii) limited spatial manipulation ability of the SPECT mobile camera handheld probe; and (iv) a wide spread of detected activity. In conclusion, clinical use of fhSPECT/US for localization of parathyroid adenomas is feasible, but shows lower sensitivity than conventional modalities and requires technical improvements.

Mediastinal parathyroid carcinoma: a case report and review of the literature

BACKGROUND

Parathyroid carcinoma (PC) is an uncommon cause of primary hyperparathyroidism (PHPT) and particularly rare in the mediastinum. Herein, we present a case of mediastinal PC and conduct a related literature review.

CASE PRESENTATION

We described a case of a 50-year-old female patient with PHPT due to mediastinal PC. She was initially admitted to a local hospital in her hometown with hypercalcemia and high blood concentrations of PTH (parathyroid hormone). The patient underwent neck parathyroidectomy and pathological examination suggested parathyroid adenoma. Although the overproduction of serum calcium and PTH declined after the surgery, calcium and PTH increased again one month later, so the patient was transferred to our hospital. A 99^mTc-sestamibi scan revealed an ectopic finding in the mediastinum, which was also indicated on the CT image. After removing the mediastinal mass, the metabolism of calcium and PTH quickly reverted to normal and the pathologic features of the mass were consistent with PC. By reviewing the related literature, we noticed that only scattered reports were published before 1982, and those were not included in the present review due to their differences with current radiological examination and treatment methods. After excluding outdated studies, we summarized and analyzed 20 reports of isolated mediastinal PC and concluded that. Parathyroidectomy remains the only curative treatment for the disease. Furthermore, the success of treatment directly depends on accurate preoperative localization.

CONCLUSION

With this study, we emphasize the importance of accurate preoperative diagnosis of mediastinal PC and improve clinicians' understanding of the disease.

Evaluation of Surgeon-Performed Ultrasonography With or Without Contrast Enhancement vs Scintigraphy in Patients With Primary Hyperparathyroidism

Importance

Scintigraphy and ultrasonography are common imaging modalities for the preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism. When comparing the 2 modalities, the benefits of ultrasonography in terms of convenience, patient comfort, duration, cost, and lack of radiation should be taken into account.

Objective

To investigate whether surgeon-performed ultrasonography, with or without contrast-enhanced ultrasonography (CEUS), is noninferior to scintigraphy for localizing pathological parathyroid glands in patients with primary hyperparathyroidism.

Design, Setting, and Participants

Prospective, paired, noninferiority cohort study performed at a high-volume tertiary referral center for parathyroidectomy with blinded examiners and a 6-month follow-up. Participants were adults (age ≥18 years) referred for parathyroidectomy due to primary hyperparathyroidism. Of 207 eligible patients, 35 were excluded, leaving 172 enrolled in the study. Inclusion lasted from September 2019 until February 2021. Follow-up ended in December 2021.

Exposures

99mTechnetium-pertechnetate/99mtechnetium-sestamibi subtraction scintigraphy with 99mtechnetium-sestamibi single-photon emission computed tomography/computed tomography, followed by surgeon-performed ultrasonography and CEUS.

Main Outcomes and Measures

The sensitivity of each imaging modality in localizing pathological parathyroid glands, calculated on a per-quadrant and a per-patient basis, respectively. The a priori noninferiority margin was a lower 95% confidence limit for the difference in sensitivity not falling below -10%.

Results

Out of 172 participants, 139 (80.8%) were women, the median (range) age was 65 (24-87) years, and the median (IQR) follow-up was 200.5 (181-280.25) days. Quadrant sensitivity (95% CI) was 70.9% (63.2%-78.5%) for ultrasonography, 68.4% (60.4%-76.5%) for ultrasonography plus CEUS, and 67.0% (60.0%-74.0%) for scintigraphy. The sensitivity difference (95% CI) compared with scintigraphy was 3.9% (-4.1% to 11.8%) for ultrasonography and 1.5% (-6.4% to 9.3%) for ultrasonography plus CEUS, establishing noninferiority for both modalities. Per-patient sensitivity was 81.4% (74.8%-86.9%) for ultrasonography and 79.1% (72.2%-84.9%) for both scintigraphy and ultrasonography plus CEUS. The sensitivity difference compared with scintigraphy was 2.3% (-6.8% to 11.4%) for ultrasonography and 0.0% (-9.1% to 9.1%) for ultrasonography plus CEUS, establishing noninferiority for both modalities.

Conclusions and Relevance

In this cohort study, conventional ultrasonography by an experienced parathyroid surgeon-sonographer was noninferior to scintigraphy and may constitute a valid first-line imaging modality in patients with primary hyperparathyroidism, even without the addition of CEUS. Further imaging should be reserved for cases that are equivocal or nonlocalizing on ultrasonography.

Submandibular Ectopic Parathyroid Adenoma: A Case Report

Primary hyperparathyroidism (PHPT) is a common endocrine disorder characterized by hypercalcemia and elevated or abnormally normal parathyroid hormone (PTH) levels, due to excessive secretion of PTH by 1 or more parathyroid glands. In this report, we discuss the diagnostic and therapeutic challenges posed by ectopic parathyroid adenomas, a rare but atypical presentation of PHPT. We present the case of a 36-year-old female with PHPT due to an ectopic parathyroid adenoma located in the submandibular region. The patient presented with bone pain and was initially evaluated with routine imaging studies, which were negative. [18F] F-choline positron emission tomography (PET)/Computed tomography revealed the ectopic adenoma, leading to successful surgical management. Ectopic parathyroid adenomas are rare but can occur in various locations, and functional imaging modalities such as choline PET can aid in their detection. Surgical resection remains the definitive treatment for parathyroid adenomas, with intraoperative PTH monitoring guiding the extent of resection. Proper evaluation and management of PHPT is essential to avoid significant morbidity. Our case adds to the growing body of literature on the importance of considering ectopic locations of parathyroid adenomas in patients with PHPT.

Does 18F-Fluorocholine PET/CT add value to positive parathyroid scintigraphy in the presurgical assessment of primary hyperparathyroidism?

Introduction

To investigate the value of presurgical 18F-FCH PET/CT in detecting additional hyperfunctioning parathyroids despite a positive 99mTc-sestamibi parathyroid scintigraphy in patients with primary hyperparathyroidism (pHPT).

Methods

This is a retrospective study involving patients with pHPT, positive parathyroid scintigraphy performed before 18F-FCH PET/CT, and parathyroid surgery achieved after PET/CT. Imaging procedures were performed according to the EANM practice guidelines. Images were qualitatively interpreted as positive or negative. The number of pathological findings, their topography, and ectopic location were recorded. Histopathology, Miami criterion, and biological follow-up were considered to ensure effective parathyroidectomy confirming the complete excision of all hyperfunctioning glands. The impact of 18F-FCH PET/CT on therapeutic strategy was recorded.

Results

64/632 scanned pHPT patients (10%) were included in the analysis. According to a per lesion-based analysis, sensitivity, specificity, positive predictive value, and negative predictive value of 99mTc-sestamibi scintigraphy were 82, 95, 87, and 93%, respectively. The same values for 18F-FCH PET/CT were 93, 99, 99, and 97%, respectively. 18F-FCH PET/CT showed a significantly higher global accuracy than 99mTc-sestamibi scintigraphy: 98% (CI: 95-99) vs. 91% (CI: 87-94%). Youden Index was 0.79 and 0.92 for 99mTc-sestamibi scintigraphy and 18F-FCH PET/CT, respectively. Scintigraphy and PET/CT were discordant in 13/64 (20%) patients (49 glands). 18F-FCH PET/CT identified nine pathologic parathyroids not detected by 99mTc-sestamibi scintigraphy in 8 patients (12.5%). Moreover, 18F-FCH PET/CT allowed the reconsideration of false-positive scintigraphic diagnosis (scinti+/PET-) for 8 parathyroids in 7 patients (11%). The 18F-FCH PET/CT influenced the surgical strategy in 7 cases (11% of the study population).

Conclusion

In a preoperative setting, 18F-FCH PET/CT seems more accurate and useful than 99mTc-sestamibi scan in pHPT patients with positive scintigraphic results. Positive parathyroid scintigraphy could be not satisfactory before neck surgery particularly in patients with multiglandular disease, suggesting a need to evolve the practice and define new preoperative imaging algorithms including 18F-FCH PET/CT at the fore-front in pHPT patients.

18F-fluorocholine PET/MRI versus ultrasound and sestamibi for the localization of parathyroid adenomas

PURPOSE

Accurate preoperative localization is imperative to facilitate a minimally invasive parathyroidectomy (MIP) in primary hyperparathyroidism (pHPT). This study aims to compare the diagnostic value of standard-of-care localization techniques (ultrasound [US] and 99mTechnetium (99mTc) -sestamibi scintigraphy) to [F-18]-fluorocholine positron emission tomography/magnetic resonance imaging (FCH-PET/MRI) to determine the additional clinical usefulness of PET/MRI in a Canadian cohort.

METHODS

We conducted a prospective, appropriately powered, study to compare the diagnostic value of -FCH PET/MRI to that of the US and 99mTc-sestamibi scintigraphy for localization of parathyroid adenomas in a patient with pHPT. The primary outcome was the per-lesion sensitivity and positive predictive value (PPV) of FCH-PET/MRI, US, and 99mTc-sestamibi scintigraphy. Intraoperative surgeon localization, parathormone levels, and histopathological findings were used as reference standards.

RESULTS

Forty-one patients underwent FCH-PET/MRI of which 36 patients had parathyroidectomy. In these 36 patients, 41 parathyroid lesions were histologically confirmed as adenomas or hyperplastic glands. Per-lesion sensitivity of FCH-PET/MRI was 82.9% and of US and 99mTc-sestamibi scintigraphy combined at 50.0%, respectively. The sensitivity of FCH-PET/MRI was superior to that of US and 99mTc-sestamibi scintigraphy (p = 0.002). In the 19 patients in whom both US and 99mTc-sestamibi scintigraphy were negative, PET/MRI correctly identified the parathyroid adenoma in 13 patients (68%).

CONCLUSIONS

FCH-PET/MRI is a highly accurate imaging modality for localization of parathyroid adenomas in a tertiary center in North America. It is a superior functional imaging modality to 99mTc-sestamibi scintigraphy alone and more sensitive for localization of parathyroid lesions than US and 99mTc-sestamibi scintigraphy combined. This imaging modality could become the most valuable preoperative localization study given its superior performance in localizing parathyroid adenomas.

18F-Fluorocholine PET/CT Compared with Current Imaging Procedures for Preoperative Localization of Hyperfunctioning Parathyroids in Patients with Chronic Kidney Disease

Hyperparathyroidism (HPT) in patients with chronic kidney disease (CKD) includes secondary (sHPT) and tertiary hyperparathyroidism (tHPT). Considering that the role of preoperative imaging in the clinical setting is controversial, in the present study we have retrospectively compared pre-surgical diagnostic performances of ¹⁸F-Fluorocholine (¹⁸F-FCH) PET/CT, cervical ultrasonography (US), parathyroid scintigraphy, and 4D-CT in a group of 30 patients with CKD and HPT (18/12 sHPT/tHPT), 21 CKD G5 including 18 in dialysis, and 9 kidney transplant recipients. All patients underwent ¹⁸F-FCH, and 22 had cervical US, 12 had parathyroid scintigraphy, and 11 had 4D-CT. Histopathology was the gold standard. Seventy-four parathyroids were removed: 65 hyperplasia, 6 adenomas, and 3 normal glands. In the whole population, in a per gland analysis, ¹⁸F-FCH PET/CT was significantly more sensitive and accurate (72%, 71%) than neck US (25%, 43%), parathyroid scintigraphy (35%, 47%), and 4D-CT (40%, 47%). The specificity of ¹⁸F-FCH PET/CT (69%) was lower than that of neck US (95%) and parathyroid scintigraphy (90%), without, however, achieving significance. ¹⁸F-FCH PET/CT was more accurate than all other diagnostic techniques when sHPT and tHPT patients were considered separately. ¹⁸F-FCH PET/CT sensitivity was significantly higher in tHPT (88%) than in sHPT (66%). Three ectopic hyperfunctioning glands (in three different patients) were all detected by ¹⁸F-FCH PET/CT, two by parathyroid scintigraphy, and none by cervical US and 4D-CT. Our study confirms that ¹⁸F-FCH PET/CT is an effective preoperative imaging option in patients with CKD and HPT. These findings may be of greater importance in patients with tHPT (who could benefit from minimally invasive parathyroidectomy) than in patients with sHPT, who often undergo bilateral cervicotomy. In these cases, preoperative ¹⁸F-FCH PET/CT may be helpful in locating ectopic glands and may guide the surgical choice for gland preservation.

Update on the current management of persistent and recurrent primary hyperparathyroidism after parathyroidectomy

Primary hyperparathyroidism (pHPT) is the third most common endocrine disease. The surgical procedure aims for permanent cure, but recurrence has been reported in 4%-10% of pHPT patients. Preoperative localization imaging is highly valuable. It includes ultrasound, computed tomography (CT), single-photon-emission CT, sestamibi scintigraphy and magnetic resonance imaging. The operation has been defined as successful when postoperative continuous eucalcemia exists for more than the first six months. Ongoing hypercalcemia during this period is defined as persistence, and recurrence is defined as hypercalcemia after six months of normocalcemia. Vitamin D is a crucial factor for a good outcome. Intraoperative parathyroid hormone (PTH) monitoring can safely predict the outcomes and should be suggested. PTH ≤ 40 pg/mL or the traditional decrease ≥ 50% from baseline minimizes the likelihood of persistence. Risk factors for persistence are hyperplasia and normal parathyroid tissue on histopathology. Risk factors for recurrence are cardiac history, obesity, endoscopic approach and low-volume center (at least 31 cases/year). Cases with double adenomas or four-gland hyperplasia have a greater likelihood of persistence/ recurrence. A 6-mo calcium > 9.7 mg/dL and eucalcemic parathyroid hormone elevation at 6 mo may be associated with recurrence necessitating long-term follow-up. 18F-fluorocholine positron emission tomography and 4-dimensional CT in persistent and recurrent cases can be valuable before reoperation. With these novel advances in preoperative imaging and localization as well as intraoperative PTH measurement, the recurrence rate has dropped to 2.5%-5%. Six-month serum calcium ≥ 9.8 mg/dL and parathyroid hormone ≥ 80 pg/mL indicate a risk of recurrence. Negative sestamibi scintigraphy, diabetes and elevated osteocalcin levels are predictors of multiglandular disease, which brings an increased risk of persistence and recurrence. Bilateral neck exploration was considered the gold-standard diagnostic method. Minimally invasive parathyroidectomy and neck exploration are both effective surgical techniques. Multidisciplinary diagnostic and surgical management is required to prevent persistence and recurrence. Long-term follow-up, even up to 10 years, is necessary.

Multi-modality parathyroid imaging: A shifting paradigm

The goal of parathyroid imaging in hyperparathyroidism is not diagnosis, rather it is the localization of the cause of hyperparathyroidism for planning the best therapeutic approach. Hence, the role of imaging to accurately and precisely localize the abnormal parathyroid tissue is more important than ever to facilitate minimally invasive parathyroidectomy over bilateral neck exploration. The common causes include solitary parathyroid adenoma, multiple parathyroid adenomas, parathyroid hyperplasia and parathyroid carcinoma. It is highly imperative for the radiologist to be cautious of the mimics of parathyroid lesions like thyroid nodules and lymph nodes and be able to differentiate them on imaging. The various imaging modalities available include high resolution ultrasound of the neck, nuclear imaging studies, four-dimensional computed tomography (4D CT) and magnetic resonance imaging. Contrast enhanced ultrasound is a novel technique which has been recently added to the armamentarium to differentiate between parathyroid adenomas and its mimics. Through this review article we wish to review the imaging features of parathyroid lesions on various imaging modalities and present an algorithm to guide their radiological differentiation from mimics.

The Dark Side of Ultrasound Imaging in Parathyroid Disease

The diagnosis of parathyroid diseases by imaging still has some intrinsic technical limitations due to the differential diagnosis of different structures of the neck that mimic the parathyroid glands. In this view, ultrasound (US) is an established, low-cost, and non-invasive imaging technique that still represents the first-line approach for evaluating patients with parathyroid disease. The objective of this article is to provide a comprehensive review of the applications of USs in clinical practice, discussing the histopathological and US characteristics of the parathyroid glands in normal and pathological conditions, the advantages of preoperative imaging, and novel updates on the most useful and currently available multiparameter US techniques.

Evolution of the Diagnosis and Treatment of Primary Hyperparathyroidism

This study aims to present the evolution of our center's approach to treating primary hyperparathyroidism (PHPT) from diagnosis to intraoperative interventions. We have also evaluated the intraoperative localization benefits of indocyanine green fluorescence angiography. This retrospective single-center study involved 296 patients who underwent parathyroidectomy for PHPT between January 2010 and December 2022. The preoperative diagnostic procedure included neck ultrasonography in all patients, [99mTc]Tc-MIBI scintigraphy in 278 patients, and, in 20 doubtful cases, [18F] fluorocholine positron emission tomography (PET) computed tomography (CT) was performed. Intraoperative PTH was measured in all cases. Indocyanine green has been administered intravenously since 2020 to guide surgical navigation using a fluorescence imaging system. The development of high precision diagnostic tools that can localize an abnormal parathyroid gland in combination with intra-operative PTH assay (ioPTH) enables the surgical treatment of PHPT patients with focused approaches and excellent results that are stackable with bilateral neck exploration (98% of surgical success). Indocyanine green angiography has the potential to assist surgeons in identifying parathyroid glands rapidly and with minimal risk, especially when pre-operative localization has failed. When everything else fails, it is only an experienced surgeon who can resolve the situation.

Localization Strategy Prior to Radiofrequency Ablation for Primary and Secondary Hyperparathyroidism

Objective: Preoperative localization in patients with primary or secondary hyperparathyroidism before radiofrequency ablation (RFA) is crucial. There is currently a lack of consensus regarding imaging protocol. Evaluating the diagnostic performance of ultrasound, four-dimensional computed tomography (4D-CT), and technetium 99m-sestamibi single-photon-emission-computed tomography/computed tomography (SPECT/CT) is necessary for RFA of hyperparathyroidism. Methods: This retrospective study recruited patients with primary or secondary hyperparathyroidism who underwent ultrasound, 4D-CT, and SPECT/CT before RFA at a single institution. The sensitivity, accuracy, and receiver operating characteristic curve analysis were used to evaluate the diagnostic performance of the imaging modalities. Results: A total of 33 patients underwent RFA for hyperparathyroidism (8 patients with primary hyperparathyroidism, 25 patients with secondary hyperparathyroidism). Ultrasound had the highest sensitivity (0.953) and accuracy (0.943), while 4D-CT had higher sensitivity and accuracy than SPECT/CT (sensitivity/accuracy, 4D-CT vs. SPECT/CT: 0.929/0.920 vs. 0.741/0.716). Combined ultrasound with 4D-CT and the three combined modalities achieved equivalent, and the highest, diagnostic performance (sensitivity 1.000, accuracy 0.989). The lesion length and volume were important predictors of the diagnostic performance of 4D-CT and SPECT/CT (area under curve of length in 4D-CT/volume in 4D-CT/length in SPECT/volume in SPECT: 0.895/0.834/0.767/0.761). Conclusion: Combined ultrasound with 4D-CT provides optimal preoperative localization prior to RFA in patients with primary or secondary hyperparathyroidism. The length and volume of parathyroid lesions are determinative of the diagnostic performance of 4D-CT and SPECT/CT.

The relationship between 18F-FCH uptake intensity and cell content in parathyroid lesions

PURPOSE

To investigate the relationship between cell content and histopathological features of parathyroid lesions and 18F-FCH uptake intensity on PET/CT images.

METHODS

Patients with primary hyperparathyroidism (age > 18) who were referred to 18F-FCH PET/CT were involved. All patients underwent parathyroidectomy. Correlation of SUVmax with following factors were statistically analysed: serum PTH, Ca, P levels and histopathological parameters, total absolute amounts of chief cell, oxyphyllic cell and clear cell components calculated by the multiplication of the volume of the parathyroid lesion and the percentage of each type of cell content (called as Absolute_chief, Absolute_oxyphyllic and Absolute_clear reflecting the total amount of each cell group).

RESULTS

A total of 34 samples from 34 patients (6M, 28F, mean age: 53.32 ± 15.15, min: 14, max: 84) who had a positive 18F-FCH PET/CT localizing at least one parathyroid lesion were involved. In the whole study group, SUVmax was found to be correlated with the greatest diameter and volume of the lesion and Absolute_chief (p = 0.004, p = 0.002 and p = 0.035, respectively). In the subgroup analysis of 28 samples with longest diameter > 1 cm, the correlation between SUVmax and Absolute_chief remained significant (p = 0.036) and correlation between SUVmax and volume and longest diameter became stronger (p = 0.011 and p > 0.001, respectively). No correlation was found between SUVmax and Absolute_oxyphyllic or Absolute_clear.

CONCLUSIONS

There might be a relationship between 18F-FCH uptake intensity and chief cell content in patients with parathyroid adenoma. Further studies with larger patient groups would be beneficial to support the data.

Parathyroidectomy for primary hyperparathyroidism: A retrospective analysis of localization, surgical characteristics, and treatment outcomes

OBJECTIVE

To evaluate parathyroidectomy for primary hyperparathyroidism (PHPT) regarding localization, surgical characteristics, and treatment outcomes.

METHODS

Seventy-eight patients who underwent parathyroidectomy for PHPT were retrospectively reviewed. The results were analyzed according to intraoperative localization technique (IOLT), intraoperative parathyroid hormone (IOPTH) monitoring, and intraoperative nerve monitoring (IONM). The localization accuracy of ultrasonography (US), computed tomography (CT), and single-photon emission computed tomography (SPECT)-CT with sestamibi Tc99m was evaluated.

RESULTS

Parathyroidectomy was successfully completed in all 78 patients, achieving 100% surgical cure. For 60 patients with IOPTH monitoring, 10-min IOPTH decreased >50% from baseline in 57 (95.0%), and they achieved surgical cure. In the remaining three (5.0%) patients with ≤50% decrease in 10-min IOPTH, 20-min IOPTH decreased >50% from baseline in two (3.3%) patients, achieving surgical cure without additional neck exploration. There were no differences in surgical cure and complications as a function of IOLT use or IOPTH monitoring. Operating time was significantly shorter with IOLT and IOPTH monitoring than without (IOLT: 70.9 min vs. 88.0 min, p = 0.013; IOPTH: 74.9 min vs. 91.9 min, p = 0.037). All 78 patients had adenoma including one patient with a double adenoma. Vocal cord paralysis was not observed in our series, regardless of IONM. US, CT, and SPECT-CT localized the pathological parathyroid gland accurately in 88.1%, 85.5%, and 86.8% of patients, respectively (p = 0.894).

CONCLUSION

The surgical outcomes of parathyroidectomy for PHPT were excellent regardless of IOLT and IOPTH monitoring. However, these techniques can maximize the performance of parathyroid surgery by reducing operating time and rescuing challenging cases.

The Diagnostic Value of Contrast Enhanced Ultrasound for Localization of Parathyroid Lesions in Primary Hyperparathyroidism: Comparison With Color Doppler Ultrasound: Comparison With Color Doppler Ultrasound

OBJECTIVES

Preoperative localization of pathological parathyroid glands with imaging is essential for focused unilateral neck exploration and minimally invasive techniques. Recently published studies suggested that contrast-enhanced ultrasonography (CEUS) had high accuracy in the localization of hyperfunctioning parathyroid glands, with a general increase in the sensitivity as compared to conventional sonography. The purpose of this study was to determine the usefulness of CEUS in the localization of parathyroid lesions relating to surgical and histopathological data, in comparison to color Doppler ultrasound (CDUS), in the same series of patients.

METHODS

Records of 142 patients who underwent parathyroidectomy were retrospectively examined comparing imaging and intraoperative/histopathologic findings.

RESULTS

The overall sensitivity of CEUS was 77.6% compared with 74.6% for CDUS, although no significative differences were found (P = .516). Conversely, CDUS has shown higher sensitivity than CEUS in the group of patients with associated thyroid pathology but there was no statistical difference (P = .529). The sensitivity for detection of multiple adenomas was the same for both procedures.

CONCLUSIONS

We found no significative superior sensitivity of CEUS also in case of concomitant thyroid pathology and multiple glands disease.

An Unusual Case of Primary Hyperparathyroidism: Case Report of a Bifocal Intrathyroidal Parathyroid Carcinoma

Intrathyroidal parathyroid carcinoma is an extremely rare cause of primary hyperparathyroidism. We reported a 51-year old woman who presented symptoms of hypercalcemia. 99mTc sestamibi single-photon emission computed tomography/computed tomography (CT) revealed a large hypermetabolic nodule in the left thyroid lobe suggestive of hyperfunctioning parathyroid tissue. 11C-methionine positron emission tomography/computed tomography (PET/CT) and 18F-fluorocholine PET/CT confirmed the nodule in the left thyroid lobe and also revealed a hypermetabolic activity on the posterior surface of the lower left pole. The patient underwent a total thyroidectomy and parathyroidectomy, and a diagnosis of bifocal intrathyroidal parathyroid carcinoma was confirmed. We present the first reported case of bifocal intrathyroidal carcinoma and discuss the discordant imaging results.