Clinical and surgical aspects of double adenoma in patients with primary hyperparathyroidism

Bilateral exploration in primary hyperparathyroidism: Double adenoma distribution and biochemical patterns over two decades

BACKGROUND

We investigated if anatomic patterns of abnormal parathyroid glands have ch anged for primary hyperparathyroidism (pHPT) as atypical biochemical presentation (normohormonal and normocalcemic) has increased.

METHODS

Retrospective review of patients with pHPT who underwent routine bilateral neck exploration.

RESULTS

2762 patients were included. The "late" cohort (2014-2020) exhibited lower preoperative calcium (10.8 vs 11.1 ​mg/dL; P ​= ​0.001) and PTH levels (101 vs. 146 ​pg/mL; P ​= ​0.001) compared to the "early" cohort (2000-2006). Patients with atypical biochemical profiles increased from 25.5% to 31.3% (P ​< ​0.001). The prevalence of single adenoma (SA) decreased (66.1% vs 58.9%, P ​= ​0.02) while the proportion of double adenoma (DA) increased (17.3% vs. 22.6%, P ​< ​0.01). Upper parathyroid adenoma(s) remained the most common finding for SA and DA in both time points.

CONCLUSIONS

Despite changes in patient characteristics, single upper adenoma and bilateral double upper adenomas remain the most common findings for patients with pHPT.

Long-term Recurrence Rates After Surgery in Primary Hyperparathyroidism

CONTEXT

Primary hyperparathyroidism (PHPT) is the most common cause of hypercalcemia, yet long-term (5- and 10-year) recurrence rates after curative surgery have been unclear.

OBJECTIVE

To perform the first systematic review and meta-analysis investigating the long-term recurrence rates of sporadic PHPT after successful parathyroidectomy.

METHODS

A comprehensive search of multiple databases (including PubMed, EMBASE, Cochrane, EBSCO-CINHAL, EMBASE, Ovid, Scopus, and Google Scholar) was performed from each database's inception to January 18, 2023. Observational studies reporting at least 5 years of follow-up data after surgical resection were included. Two reviewers independently screened articles for relevance. Of 5769 articles initially identified, 242 were examined in full-text review and 34 were deemed eligible for inclusion. Two authors independently performed data extraction and study appraisal, using the National Institutes of Health study quality assessment tools.

RESULTS

Of 30 658 participants, 350 patients (1.1%) experienced recurrence after resection. A meta-analysis of proportions was performed to obtain the pooled recurrence rates. The pooled estimate for overall recurrence rate was 1.56% (95% CI 0.96-2.28%; I2 = 91%). The pooled estimates for 5- and 10-year recurrence rate after resection were 0.23% (0.04-0.53%, 19 studies; I2 = 66%) and 1.03% (0.45-1.80%, 14 studies; I2 = 89%), respectively. Sensitivity analyses did not find a statistically significant difference when adjusting for study size, diagnosis, or surgical approach.

CONCLUSION

Approximately 1.56% of sporadic PHPT patients eventually develop recurrence following parathyroidectomy. The initial diagnosis and procedure type does not influence recurrence rates. Consistent long-term follow-up is warranted to help identify recurrent disease.

Relative Perfusion Differences between Parathyroid Adenomas and the Thyroid on Multiphase 4DCT

A multiphase 4DCT technique can be useful for the detection of parathyroid adenomas. Up to 16 different phases can be obtained without significant increase of exposure dose using wide beam axial scanning. This technique also allows for the calculation of perfusion parameters in suspected lesions. We present data on 19 patients with histologically proven parathyroid adenomas. We find a strong correlation between 2 perfusion parameters when comparing parathyroid adenomas and thyroid tissue: parathyroid adenomas show a 55% increase in blood flow (BF) (p < 0.001) and a 50% increase in blood volume (BV) (p < 0.001) as compared to normal thyroid tissue. The analysis of the ROC curve for the different perfusion parameters demonstrates a significantly high area under the curve for BF and BV, confirming these two perfusion parameters to be a possible discriminating tool to discern between parathyroid adenomas and thyroid tissue. These findings can help to discern parathyroid from thyroid tissue and may aid in the detection of parathyroid adenomas.

Preoperative Localization of Parathyroid Adenomas with Diffusion MR Imaging: Readout-segmented versus Single-shot Echo-planar Imaging

PURPOSE

To evaluate whether readout-segmented echo-planar imaging (RS-EPI) diffusion-weighted imaging (DWI) can reduce image distortion and improve the lesion identification in parathyroid adenomas (PTAs) compared to single-shot EPI (SS-EPI) DWI, and to determine whether PTAs can be differentiated from other soft tissue structures of the head and neck region by using the apparent diffusion coefficient (ADC) value.

METHODS

We retrospectively analyzed the preoperative MR images including DWI of 24 patients with surgically confirmed PTA. RS-EPI and SS-EPI DWI were evaluated by two independent readers for the identification of the lesions and distortion. The ADC values of the PTAs were compared with those of thyroid glands and cervical lymph nodes.

RESULTS

RS-EPI provided significantly less distortion compared to SS-EPI. RS-EPI tended to have better lesion identification compared with SS-EPI without a statistically significant difference. On SS-EPI, the PTAs had significantly higher ADC values compared with the cervical lymph nodes. On RS-EPI, the PTAs had significantly higher ADC values compared with the thyroid glands and cervical lymph nodes.

CONCLUSION

RS-EPI reduces the DWI distortion in PTAs. The ADC value obtained using RS-EPI enables the differentiation of PTAs from nearby structures, such as thyroid glands and cervical lymph nodes.

High parathyroid hormone levels after parathyroidectomy for parathyroid adenoma are not related to the cellularity of the remaining glands

BACKGROUND

Patients with primary hyperparathyroidism (PHPT) treated surgically occasionally have normalized calcium, but persistently high parathyroid hormone (PTH). We hypothesized that a possible explanation for this phenomenon is an underlying hyperplasia rather than adenoma.

METHODS

Retrospective cohort of patients who underwent parathyroidectomy for PHPT with biopsy of a normal-appearing parathyroid gland were included. Cellularity level of each biopsy and of the adenoma's rim was determined.

RESULTS

Forty-seven patients were included. Of them, 19 (40%) had postoperative normocalcemia but elevated PTH. There was no correlation between cellularity either in the rim or of the normal-appearing parathyroid gland and postoperative PTH. The postoperative high PTH group had higher preoperative PTH (P = 0.001) and larger adenomas (P = 0.025).

CONCLUSIONS

High PTH levels after successful parathyroidectomy in patients with primary hyperparathyroidism do not appear to result from underlying hyperplasia. A possible alternative explanation is that these patients have a higher preoperative burden of disease.

Surgeon-performed Ultrasound for Primary Hyperparathyroidism

The role of preoperative parathyroid imaging continues to evolve. This study evaluated whether surgeon-performed ultrasound (U/S) obviates the need for other imaging studies and leads to a focused exploration with a high degree of surgical success. From July 2010 to February 2012, 200 patients presenting with nonfamilial primary hyperparathyroidism underwent neck U/S in the surgeon's office. The U/S interpretation was classified as Class 1 if an adenoma was identified with high confidence, Class 2 if a possible but not definite enlarged gland was imaged, and Class 0 (zero) if no adenoma was identified. The findings were correlated with subsequent intra-operative findings. There were 144 Class 1 U/Ss (72%); of 132 patients coming to surgery, 96.2 per cent had surgical findings concordant with preoperative U/S and all had apparent surgical cure. Twenty-nine patients (14.5%) had Class 2 U/S; the 31 per cent confirmed false-positives in this group were usually colloid nodules. Fourteen of 27 with Class 0 U/S underwent surgery after being offered dynamically enhanced computed tomography scan. All 200 patients were apparent surgical cures. Surgeon-performed U/S is expedient, convenient, inexpensive, and accurate. A clearly identified adenoma can safely lead to a focused limited exploration and avoid additional imaging 93 per cent of the time.

Role of Venous Sampling in the Diagnosis of Endocrine Disorders

Venous sampling is the gold standard for localizing abnormal hormone secretion in several endocrine disorders. The most common indication for venous sampling is in the workup of primary aldosteronism, adrenocorticotropic hormone-dependent Cushing's syndrome, and hyperparathyroidism. In experienced hands, venous sampling is safe and accurate. This review discusses the role of venous sampling in the workup of endocrine disease, describing the underlying anatomy and pathophysiology, as an understanding of these concepts is essential for technical and clinical success.

A Controversial Problem: Is There a Relationship between Parathyroid Hormone Level and Parathyroid Size in Primary Hyperparathyroidism?

The current study was undertaken with the aim of studying the relationship between parathyroid hormone and hyperfunctioning parathyroids by a sophisticated method of analysis. Our clinical study included 25 patients undergoing surgery for primary hyperparathyroidism. The measurement of basal circulating intact PTH (pg/ml) and the volume (mm3) of the removed gland(s) were recorded. It was essential for the distribution of the sample values to be normal before Pearson's correlation and regression analysis were performed. The Kolmogorov-Smirnov test showed sufficient sample data agreement (p>20%) with normal distribution after their transformation into natural logarithm (ln) and so statistical analysis was performed utilizing ln transformed data. The regression line between basal ln of iPTH levels (x) and ln of tumor volume (y) was highly significant (y=2.3828+1.0424 x, r=.72504, p<.0001). In our opinion, the above is a correct statistical procedure with reliable results.

How long should we follow patients after apparently curative parathyroidectomy?

BACKGROUND

Little is known about the long-term recurrence risk for primary hyperparathyroidism after immediately "curative" parathyroidectomy. This study aimed to evaluate the risk of recurrent hyperparathyroidism in the 10 years after operation.

METHOD

We retrospectively identified patients with sporadic primary hyperparathyroidism undergoing initial parathyroidectomy between November 1, 2000 and June 30, 2005. Recurrence was defined as serum calcium >10.2 mg/dL after 6 months from operation. Kaplan-Meier estimates and Cox proportional hazards were used to evaluate disease-free survival and predictors of recurrence.

RESULTS

We evaluated 196 patients with a 14.8% 10-year recurrence rate. Median time to recurrence was 6.3 years (interquartile range 3.4-10.8 years), and 34.5% of all recurrences were identified >10 years after operation. There was no difference in recurrence between open and minimally invasive operation (P = .448). Double adenomas (P = .006), intraoperative parathyroid hormone drop <70% (P = .015), and young age (P = .032) were predictive of disease recurrence. Multivariable analysis demonstrated that older age was protective against recurrence (hazard ratio 0.97, 95% confidence interval 0.94-0.99, P = .034), while double adenomas (hazard ratio 3.52, 95% confidence interval 1.23-10.08, P = .019) were an independent predictor for recurrence.

CONCLUSION

The long-term recurrence rate for sporadic primary hyperparathyroidism after "curative" parathyroidectomy is likely greater than reported. With over one-third of our institutional recurrences at >10 years after the initial operation, long-term follow-up is essential.

Parathyroid ultrasonography: the evolving role of the radiologist

Previously, radiologists played a limited role in the treatment of parathyroid disease, primary focusing on the preoperative localization of parathyroid lesions responsible for hyperparathyroidism. But, the widespread use of high-resolution ultrasound has lead to the increasing detection of parathyroid incidentalomas (PTIs). Consequently, radiologists may be required to differentiate PTIs from thyroid lesions, which is most reliably accomplished through the fine needle aspiration-parathyroid hormone analysis. Various nonsurgical treatment modalities for hyperfunctioning parathyroid lesions have been developed with some efficacy. Especially for symptomatic nonfunctioning parathyroid cysts, simple aspiration is a first-line procedure for diagnosis and treatment, while ethanol ablation is a subsequent treatment modality for recurrent cases.

Recurrent and persistence primary hyperparathyroidism occurs more frequently in patients with double adenomas

INTRODUCTION

The incidence of recurrent primary hyperparathyroidism (PHPT) had been reported to be between 1% and 10%. The purpose of this study was to examine if patients with multigland disease have a different recurrence rate.

METHODOLOGY

A retrospective analysis of a prospectively collected database was performed on patients with PHPT who underwent parathyroidectomy at one institution between 2001 and 2013. Patients who underwent initial parathyroidectomy with at least 6 mo of follow-up were included and were divided into three groups according to operative notes: single adenoma (SA), double adenoma (DA), and hyperplasia (HP). An elevated postoperative serum calcium level within 6 mo of surgery was defined as a persistent disease, whereas an elevated calcium after 6 mo was defined as a recurrence.

RESULTS

In total, 1402 patients met inclusion criteria, and the success rate of parathyroidectomy was 98.4%. The mean age was 60±14 y and 78.5% were female. Among them, 1097 patients (78%) had SA, 124 patients (9%) had DA, and 181 patients had HP (13%). The rate of persistent PHPT was higher among patients with DA (4%) versus SA (1.3%) and HP (2.2%) (P=0.0049). Moreover, the recurrence rate was higher among patients with DA (7.3%) versus SA (1.7%) and HP (4.4%) (P=0.0005) with identical median follow-up time. The median of the follow-up was 11 mo for patients with SA, 12.5 for patients with DA, and 12 for patients with HP (P=0.1603).

CONCLUSIONS

Recurrent and persistent PHPT occur more frequently in patients with DA. These data suggest that DA in some cases could represent asymmetric or asynchronous hyperplasia. Therefore, patients with DA may warrant more rigorous intraoperative scrutiny and more vigilant monitoring after parathyroidectomy.

Involvement of α-klotho, fibroblast growth factor-, vitamin-D- and calcium-sensing receptor in 53 patients with primary hyperparathyroidism

The presentation of patients with primary hyperparathyroidism is often atypical and ranges from normocalcemic, primary hyperparathyroidism to severe, symptomatic hypercalcemia. G-protein-coupled, calcium-sensing receptor (CaSR), vitamin D receptor (VDR), and fibroblast growth factor receptor (FGFR)/klotho complexes seem to be involved in the development of pHPT. Parathyroid glands from 53 patients with pHPT and normal parathyroid tissue from 7 patients were obtained during parathyroidectomy. Conventional detailed morphological and immunohistochemical analyses of parathyroid glands were performed after dividing each slide in a 3 × 3 array. From morphology, the number of lipocytes was significantly lower in parathyroid tissue glands in the pHPT group (p < 0.001). Protein expressions of klotho, CaSR, and VDR were significantly reduced in the pHPT compared with the control group (p = 0.004, p = 0.007, p < 0.001). No differences were seen between the two groups (p = 0.35) regarding expression of FGFR. Correlations between expression showed significant positively correlations between klotho and CaSR and FGFR and VDR. No correlations between klotho expression and serum calcium levels could be detected (R = -0.13, p = 0.66), but there were positive correlations between expressions of CaSR/serum phosphate and klotho/serum phosphate. Impaired protein expression of CaSR and VDR seem to be involved in the development of pHPT. The role of the FGFR/klotho-axis remains still unclear. Correlations between protein expression of CaSR and serum phosphate and klotho and serum phosphate levels could be detected. Whether these findings give new insights into the pathogenesis of the disease is yet unknown and has to be elucidated.

Hormone, relationships of parathyroid gamma counts, and adenoma mass in minimally invasive parathyroidectomy

OBJECTIVE

To better understand relationships of parathyroid hormone (PTH) production, adenoma gamma counts, and adenoma mass in patients undergoing minimally radioguided invasive parathyroidectomy for primary hyperparathyroidism from single-gland disease.

STUDY DESIGN

A prospective review of 104 patients operated on by a single surgeon.

SETTING

University tertiary hospital.

SUBJECTS

Adults who have primary hyperparathyroidism due to a single gland.

RESULTS

There were 23 men and 81 women with an average age of 63 years. The mean (SD) adenoma mass was 0.78 (0.69) g (median, 0.57 g). The mean (SD) percent of background for the adenoma was 120.2 (90.5). Preoperative PTH and percent of background gamma count of the adenoma showed a likely correlation with a Spearman ρ value of 0.2039 and a P value of .037. There were significant correlations between both percent of background of the adenoma and adenoma mass (Spearman ρ = 0.4991 and P < .0001). Preoperative PTH and adenoma mass also showed a significant positive correlation (Spearman ρ = 0.308 and P = .002).

CONCLUSION

There exist correlations between gland mass, radioactivity, and PTH level. Adenoma radiation counts do not appear to be a proxy for changes in PTH levels measured during surgery as has been reported. Intraoperative PTH has been shown by others not to be necessary when doing radioguided parathyroid surgery if the Norman rule is observed. However, a radioguided technique and intraoperative PTH can provide complementary information in making an assessment of completion of parathyroid procedures.

Point-of-care rapid intraoperative parathyroid hormone assay of needle aspirates from parathyroid tissue: a substitute for frozen sections

BACKGROUND

The intraoperative parathyroid hormone (IOPTH) assay is an important tool that facilitates targeted parathyroidectomy and may increase surgical cure rates. We sought to evaluate the utility of a point-of-care assay to distinguish parathyroid adenomas from nonparathyroid tissues, which can sometimes pose a challenge during parathyroidectomy and is commonly achieved with the use of frozen sections. We hypothesized that point-of-care rapid IOPTH assays of needle aspirates from suspected adenomas would be faster and equal in accuracy to frozen sections.

METHODS

Parathyroid and nonparathyroid lesions were excised, and the tissues were needle aspirated, diluted in saline, and submitted to a rapid IOPTH assay located in the operating room. Frozen sections were simultaneously sent for analysis. The time intervals to result availability were tracked and compared using a paired t test.

RESULTS

Point-of-care IOPTH assays of needle aspirates were available in a mean (±SD) of 11.6 ± 1.5 minutes compared to 18.7 ± 4.0 minutes for frozen sections (P = .005). The findings were concordant 100% of the time for both parathyroid (mean parathyroid hormone [PTH] > 3338.9 pg/mL) and parathyroid tissues (mean PTH = 8.7 pg/mL).

CONCLUSION

Point-of-care IOPTH assay of needle aspirates is an accurate method of distinguishing parathyroid from nonparathyroid tissues. It is suggested that this would be particularly useful in instances where use of IOPTH is planned for assessment of a drop in serum PTH.

Primary hyperparathyroidism: Skeletal and non-skeletal effects, diagnosis and management

Primary hyperparathyroidism (PHPT) is the third most common endocrinopathy seen today, and is most frequently found in the 6th to 7th decade of life. PHPT can present with various degrees of symptoms, and can affect many organ systems, including the skeletal, renal, central nervous system and cardiovascular system. Despite this, the most common presentation of hyperparathyroidism is "asymptomatic" with the diagnosis being made incidentally with the initial finding of hypercalcemia on routine laboratory studies, leading to further investigation. Surgical versus medical management is usually based on factors such as age and complications related to hyperparathyroidism (i.e. the presence of renal stones, renal insufficiency and bone loss and significant increases in serum calcium). Treatment options include parathyroidectomy, bisphosphonates, calcitonin and calcimimetics. In this review, we discuss primary hyperparathyroidism in detail with a focus on clinical manifestations particularly in the elderly population. We highlight the indications for surgical versus medical management and compare some of the uses of newer therapeutic agents relative to traditional ones.

Normal PTH levels in primary hyperparathyroidism: still the same disease?

PURPOSE

Previous studies have suggested that primary hyperparathyroidism (pHPT) with only normal parathyroid hormone (PTH) levels is a milder, less symptomatic form of pHPT. This study investigates symptoms, laboratory values, imaging, and outcomes of sporadic pHPT patients with normal PTH values.

METHODS

We reviewed our prospectively collected database of 861 patients with sporadic pHPT who underwent parathyroidectomy between December 1999 and June 2010. Patients with only normal PTH values for 6 months before surgery were compared to a randomized control group of sporadic pHPT patients with elevated PTH, matched 1:2 for age and gender.

RESULTS

Fifty-eight (7%) patients had only normal PTH values within 6 months of surgery. The mean PTH was 55.1 pg/ml in the normal PTH group and 151.3 pg/ml in the control group (n=116). There was no difference in preoperative calcium values, subjective symptoms, bone health, or the frequency of single-gland disease (SGD; 88% vs. 91%) between the two groups, but the normal PTH group had higher preoperative vitamin D values (30.8 vs. 21.4 ng/ml; P<0.001), smaller adenomas (405 vs. 978 mg, P<0.001), and more frequently underwent bilateral neck exploration (57% vs. 49%). There was a trend toward lower sensitivity of preoperative imaging in the normal PTH group.

CONCLUSIONS

Patients with pHPT and either elevated or normal PTH levels present with similar symptoms and calcium levels. The majority of patients with normal PTH have SGD, although adenomas are smaller. This may explain why patients with normal PTH values have less sensitive imaging and more frequently require four-gland exploration.

Weight difference between double parathyroid adenomas is the cause of false-positive IOPTH test after resection of the first lesion

BACKGROUND

Some patients with double parathyroid adenoma show a greater than 50% decline in intraoperative parathyroid hormone (IOPTH) after resection of the first lesion. The present study was designed to test the hypothesis that significant adenoma weight differences may explain this inappropriate decline of IOPTH.

METHODS

We reviewed prospective database records at two tertiary institutions. Patients with a histopathologic diagnosis of double adenoma and no familial history of hyperparathyroidism were included. Diagnosis of double adenoma was confirmed either preoperatively (double uptake), intraoperatively (bilateral exploration), or at reintervention. IOPTH was determined following the Miami protocol. The 10-min postexcision sample was considered as the 0-min sample for IOPTH determinations at the time of resection of the second lesion.

RESULTS

Thirteen patients met the inclusion criteria. After resection of the first lesion, IOPTH failed to decline in four patients and a second adenoma was removed. They had similar weight (404 vs. 598 mg). In nine patients IOPTH showed a false greater than 50% decline. These patients had the largest adenoma removed first (846 +/- 226 mg), and only two had normal PTH serum concentrations 10 min after resection. The second adenoma was always smaller (284 +/- 177 mg; P = 0.02) and its resection either during the same operation (7 cases) or at reoperation (2 cases) led to normalization of IOPTH at 10 min in all cases.

CONCLUSIONS

Two-thirds of patients with double parathyroid adenoma show a false-positive decline of IOPTH after resection of the first adenoma. This appears to be due to the initial removal of the larger lesion.

Twice-Recurrent Primary Hyperparathyroidism Due to Parathyroid Hyperplasia in an Ectopic Supernumerary Gland

OBJECTIVE

To describe a patient with multiple recurrences of primary hyperparathyroidism during a 24-year period.

METHODS

We present the long-term history, including clinical and laboratory evaluations as well as findings on surgical interventions, in a 42-year-old man with recurrent hyperparathyroidism. In addition, the relevant literature is briefly reviewed.

RESULTS

At initial surgical exploration when the patient was 18 years old, a single enlarged parathyroid gland and a normal-appearing ipsilateral gland were found. After more than a decade without symptoms, the patient experienced recurrent symptomatic hypercalcemia. Surgical exploration revealed symmetric multiglandular disease that was treated by resection of 3 enlarged parathyroid glands and implantation of a portion of 1 gland in the forearm. After another 6-year asymptomatic period, the patient had recurrent symptoms and was found to have recurrent hypercalcemia. Surgical intervention revealed an enlarged supernumerary gland in an ectopic location. A preoperative technetium Tc 99m sestamibi scan and intravenous administration of methylene blue were helpful in identifying the ectopic parathyroid gland in the left carotid sheath.

CONCLUSION

This case illustrates the difficulty of determining which of a patient's parathyroid glands may become hyperfunctioning and the importance of considering whether supernumerary glands may be present. The case also demonstrates the need for long-term follow-up before a patient is considered "cured" of hyperparathyroidism.

Existence and Anatomic Distribution of Double Parathyroid Adenoma

BACKGROUND

Double parathyroid adenomas occur in 2% to 15% of primary hyperparathyroidism cases, but the very existence of double adenomas has been controversial. This study was conducted to evaluate the clinical significance and anatomic distribution of parathyroid double adenomas.

STUDY DESIGN

Mono-institutional retrospective study of the medical records of 183 unselected consecutive patients who underwent intervention for primary hyperparathyroidism between 1996 and 2003.

RESULTS

A total of 14 (7.65%) patients were found to have double parathyroid adenomas. Intraoperative parathyroid hormone (PTH) levels were measured in every case. Two enlarged parathyroid glands were identified in four possible configurations: two both superior, one both inferior, two both right, three both left, two right superior and left inferior, and three left superior and right inferior. There was a preferential crossed bilateral distribution of double adenomas. In all patients, intraoperative PTH levels dropped by at least 50% from baseline after removal of both abnormal parathyroid glands. In this series, no patient developed persistent hypoparathyroidism or had recurrent laryngeal nerve injuries or neck hematoma. All patients remained normocalcemic 9 to 96 months postoperatively. One patient had persistently elevated PTH values with normal serum calcium levels.

CONCLUSION

The drop in intraoperative PTH levels and maintenance of normocalcemia postoperatively confirm previous reports that double adenomas do exist and are not simply missed cases of four-gland hyperplasia. There was a preferential crossed bilateral distribution of double adenomas in this series.

Re-operation for hyperparathyroidism

INTRODUCTION

Re-operation for hyperparathyroidism (HPT) represents a challenge for experienced endocrine surgeons. The present study reviews the technical and pathological factors for failure of initial surgery and identifies strategies to approach re-operative parathyroidectomy.

METHODS

Clinical details, operation notes, pathology, localization studies and complications for re-operative cases performed by three surgeons were reviewed.

RESULTS

Over a 10-year period there were 40 re-operative cases with a 98% success rate. There were 31 patients with primary HPT, 21 with persistent primary (PP) and 10 with recurrent primary (RP). Multigland disease (MGD) was present in 19 of the 31 (61%) primary HPT cases. The culprit gland was ectopic in 14 cases, at a normal location in 10 and there was regrowth at previously excised sites or remnant disease in 10. There were nine patients with secondary HPT, four with persistent secondary (PS) and five with recurrent secondary (RS). The culprit gland was ectopic in five, at a normal location in four and regrowth at a previously excised site in two. Pre-operative investigations were employed in all cases and the most helpful were sestamibi scan (S) and selective venous sampling (SVS) for parathyroid hormone (PTH) concentration. True positive localizations for S was in 20 of 34 cases (59%), SVS in seven of nine (78%), computed tomography (CT) in seven of 17 (41%) and ultrasound scan (USS) in 10 of 28 (36%).

CONCLUSIONS

Re-operative parathyroidectomy can be performed by experienced surgeons with a very high success rate and minimal complications.

Primary, secondary, and tertiary hyperparathyroidism

Primary, secondary, and tertiary hyperparathyroidism have evolved since their original description. What was once a debilitating disease has now become one with few symptoms on initial presentation. Complications from these disorders have decreased significantly because of earlier detection. Improved management of patients with chronic renal disease has also limited complications among those with secondary and tertiary hyperparathyroidism. Appropriate management is essential even in the early phase of the disorder to minimize the morbidities that may result if left untreated.

Post-Parathyroidectomy Hypocalcemia: Incidence, Risk Factors, and Management

The purpose of this study was to evaluate the incidence and severity of hypocalcemia after parathyroidectomy and delineate its risk factors. Data was retrieved from a prospective database. Patients with postoperative hypocalcemia were identified and risk factors were investigated including primary versus renal hyperparathyroidism (HPT), preoperative calcium, parathyroid hormone (PTH) and alkaline phosphatase levels, gland weight, pathology, extent of surgery, and reoperative surgery. Of the 162 patients who underwent parathyroidectomy, 84 (52%) were hypocalcemic postoperatively: 55 (42%) of 132 patients with primary and 29 (97%) of 30 patients with renal HPT ( P = 0.0001). Patients with renal HPT had more profound hypocalcemia with a mean ± SD calcium of 7.34 mg/dL ± 1.07 versus 7.76 mg/dL ± 0.59 for patients with primary HPT ( P < 0.05). Symptoms were present in 28 (51%) of 55 patients with primary and 13 (45%) of 29 patients with renal HPT. Only three (2%) patients with primary compared to 29 (97%) with renal HPT were treated with intravenous calcium. The average length of stay for hypocalcemic patients was 0.7 days for primary HPT versus 4.7 days for renal HPT ( P < 0.0005). Patients with primary HPT who underwent subtotal parathyroidectomy had significantly lower postoperative calcium levels (7.95 mg/dL ± 0.64) than patients who had a single or double adenoma removed (8.49 mg/dL ± 0.79) ( P = 0.036). No other factor was predictive of postoperative hypocalcemia. Patients with renal HPT develop profound postoperative hypocalcemia requiring intravenous calcium and vitamin D therapy. Hypocalcemia in patients with primary HPT develop less severe hypocalcemia that is amenable to outpatient oral calcium therapy and should be routinely initiated following subtotal parathyroidectomy.

Double adenomas revisited: nonuniform distribution favors enlarged superior parathyroids (fourth pouch disease)

BACKGROUND

A double adenoma (DA) is a recognized clinical entity of primary hyperparathyroidism (HPT) and is presumed to have uniform location distribution. We reviewed our experience with 2-gland parathyroid disease to identify anatomic patterns and implications for surgical management.

METHODS

Clinical characteristics were reviewed for 828 consecutive patients with HPT at 2 endocrine referral centers that practice bilateral neck exploration with intraoperative parathyroid hormone (IOPTH) measurement.

RESULTS

Fifteen percent (127 of 828) of HPT patients demonstrated 2 enlarged glands; 13% (107 of 828), 3- or 4-gland hyperplasia; and 71% (592 of 828), single adenomas. DAs in superior parathyroids affected 57 of 127 (45%) patients, an observed frequency 3-fold higher than expected (P<.001, chi-square test). DAs were larger than normal glands (240+/-575 mg vs 28+/-23 mg, P<.001), and superior parathyroid adenomas were larger than adenomas at other sites (421+/-983 mg vs 202+/-353 mg, P=.002). Technetium 99 metastable (Tc99m)-sestamibi imaging and IOPTH identified DAs correctly in only 5 of 84 (6%) and 19 of 75 (25%) of patients tested, respectively.

CONCLUSIONS

DAs have nonuniform anatomic distribution with predilection for abnormal growth in bilateral superior parathyroids-embryologic remnants of the fourth branchial pouch. Since additional abnormal glands were detected by observation with technetium 99 metastable (Tc99m)-sestamibi imaging and IOPTH rarely aiding detection, unilateral neck exploration may predispose to persistent or recurrent HPT.

Metachronous Double Parathyroid Adenomas Involving Two Different Cell Types: Chief Cell and Oxyphil Cell

OBJECTIVE

To describe a patient with the rare occurrence of metachronous double parathyroid adenomas involving two different cell types.

METHODS

We present a case report and a summary of the related literature.

RESULTS

Double parathyroid adenomas are rare, occurring in 1.7 to 9% of patients with primary hyperparathyroidism. Most double parathyroid adenomas are synchronous lesions; few metachronous double parathyroid adenomas have previously been reported. Most parathyroid adenomas are of the chief cell variety, with oxyphil cell adenomas occurring in less than 1% of cases. In a 73-year-old man with no prior history or known family history of endocrine disease, primary hyperparathyroidism developed, and cervical ultrasonography demonstrated a mass in the right side of the neck. Subsequent parathyroidectomy revealed a right superior chief cell adenoma. Postoperatively, the patient's parathyroid hormone and serum calcium levels returned to normal and remained so for at least 9 years. Twelve years after the first operation, recurrent hyperparathyroidism prompted repeated surgical exploration of the neck, which disclosed a large left superior parathyroid mass. Surgical excision and histologic examination revealed the lesion to be an oxyphil cell adenoma.

CONCLUSION

To our knowledge, this is the first reported case of metachronous double parathyroid adenomas involving two different cell types: chief cell and oxyphil cell.

Intraoperative parathyroid hormone monitoring fails to detect double parathyroid adenomas: a 2-institution experience

BACKGROUND

We hypothesized that intraoperative parathyroid hormone monitoring (IOPTH) reliably would detect double parathyroid adenomas.

METHODS

This was a retrospective study of 20 patients undergoing conventional parathyroidectomy with resection of exactly 2 abnormal glands. Full exploration was performed regardless of IOPTH values, which were measured after anesthetic induction and 5 and 10 minutes following removal of the first abnormal parathyroid gland. Failure to fall below 50% of baseline value by 10 minutes following resection of the first gland indicated the presence of multiglandular disease.

RESULTS

All patients were cured. All excised glands were hypercellular on histology. Mean IOPTH values in 9 of the 20 patients with true negative results (noncurative decrease, another gland present) were 66% +/- 7% at 5 minutes and 83% +/- 15% at 10 minutes. The IOPTH values in 11 of the 20 patients with false positive results (curative decrease, another gland present) were 28% +/- 4% at 5 minutes and 18% +/- 2% at 10 minutes. The false positive rate of IOPTH was 55%.

CONCLUSIONS

We found that IOPTH failed to reliably detect the presence of double parathyroid adenomas. These data suggest that caution should be exercised when terminating limited parathyroid exploration based on a curative fall in IOPTH values.

Parathyroid imaging with Tc-99m sestamibi planar and SPECT scintigraphy

Technetium-99m sestamibi planar and single-photon-emission computed tomographic scintigraphy is useful in the diagnosis of parathyroid gland disease. To understand the various patterns of parathyroid disease, it is important to understand parathyroid embryology and anatomy. The spectrum of parathyroid disease demonstrated with Tc-99m sestamibi scintigraphy includes eutopic disease, ectopic disease, solitary adenoma, double or multiple adenomas, cystic adenoma, lipoadenoma, multiple endocrine neoplasia, hyperfunctioning parathyroid transplant, entities with atypical washout, and nonparathyroid entities that take up Tc-99m sestamibi. The diagnosis of parathyroid tumors with Tc-99m sestamibi scintigraphy is based on the difference in clearance rates between the thyroid and diseased parathyroid glands, and any condition that interferes with radiotracer clearance will limit the effectiveness of the study. The technique is most clearly indicated for the preoperative evaluation of recurrent or persistent hyperparathyroidism, but it is increasingly being used before the initial surgical exploration as well. Subtraction Tc-99m sestamibi and iodine-123 scintigraphy may be helpful in difficult cases. Parathyroid hyperplasia, multisite parathyroid disease, and concomitant thyroid and parathyroid disease remain potential hurdles for this scintigraphic technique, and optimal handling of these problems still relies heavily on the skill and experience of the endocrine surgeon.

Heterogeneous gland size in sporadic multiple gland parathyroid hyperplasia

BACKGROUND

The success rate for bilateral exploration in patients with primary hyperparathyroidism approaches 95%. Multiglandular parathyroid hyperplasia accounts for approximately 10% to 30% of primary hyperparathyroidism. The incidence of recurrent or persistent hyperparathyroidism is highest in familial forms of the disease, in which multiglandular disease is more common; this may be due to asymmetric enlargement of parathyroid glands. Because of improvements in tumor-imaging capability, some surgeons are now advocating unilateral exploration for primary hyperparathyroidism, but there is limited experience concerning how often these imaging methods fail.

STUDY DESIGN

The outcomes of 7 patients who had sporadic primary hyperparathyroidism with multigland hyperplasia were reviewed. We gathered demographic data and laboratory values and reviewed radiologic tests, surgical findings, pathologic findings, and postoperative followup.

RESULTS

All patients underwent preoperative localization with ultrasonography and technetium/sestamibi scans. The sensitivity of these two tests for the dominantly enlarged gland was 100% for both, but dropped to 0% and 5%, respectively, for all other enlarged glands. The sensitivity of CT and MRI for the dominant tumor was 67% (2 of 3) and 50% (1 of 2), respectively. Six of 7 patients underwent subtotal (3(1/2) gland) parathyroidectomy. The mean volume of all glands was 1.51+/-5.89 cm3 compared with a mean of 5.66+/-11.4 cm3 for all dominant glands and 0.123+/-0.1 cm3 for all nondominant hyperplastic glands. There was a large amount of variability between the volumes of dominant and other glands as demonstrated by large SDs from the mean.

CONCLUSIONS

There is a marked heterogeneity in gland size in patients with sporadic multigland hyperplasia, which is similar to that found in multiple endocrine neoplasia type I. This heterogeneity may result in failure to recognize multigland disease if a unilateral neck exploration is performed. Intraoperative parathyroid hormone assay may prove to be an important adjunct in this population of patients who have unsuspected multigland disease.

Non-synchronous double adenoma of the parathyroid gland

A 46-year-old female underwent an excision of a parathyroid adenoma diagnosed as recurrent primary hyperparathyroidism 24 years after the initial excision of a parathyroid adenoma. We report a case of non-synchronous double adenomas of the parathyroid glands documented histopathologically.