Primary hyperparathyroidism: do perioperative biochemical variables correlate with parathyroid adenoma weight or volume?

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.

Giant Parathyroid Adenoma: A case Report

Giant parathyroid adenoma (GPA) is a large tumor weighing more than 3.5 g but can weigh as much as 110 g as compared to parathyroid adenomas which usually weigh in the vicinity of 1 g and measure around 1-2 cm. These mainly present with primary hyperparathyroidism. We describe an interesting case and clinical course of a young woman with giant parathyroid adenoma. A 30-year-old Indian female presented with acute pancreatitis and acute kidney injury and was found to have hypercalcemia and hyperparathyroidism on further evaluation. Her physical examination revealed firm, non-tender, and mobile swelling of size 5 × 2 cm on the left side of her neck. USG neck showed a large heterogenous hypoechoic lesion in the left lower pole region of the left thyroid gland measuring 50 × 24 × 29 mm with a volume of 18 ccs. A parathyroid scan was performed using 99Tc Sesta MIBI tracer which was suggestive of a large adenoma in relation to the left lobe of the thyroid gland. She underwent minimally invasive parathyroidectomy with excision of left parathyroid adenoma under general anesthesia. Intraoperative frozen section confirmed the specimen to be parathyroid tissue. Her parathyroid hormone (PTH) level decreased from 1900 pg/ml in the pre-operative level to 242 pg/ml in the immediate postoperative period.

The Relationship between Planar and SPECT/CT Parameters and Functional Markers in Primary Hyperparathyroidism

This study aimed to investigate the relationship between quantitative and volumetric parameters of technetium-99-methoxyisobutylisonitrile (99mTc-MIBI) single-photon emission computed tomography/computed tomography (SPECT/CT) imaging and hormonal and biochemical markers in primary hyperparathyroidism (PHPT) patients with single adenoma. In this retrospective study, 70 patients with a single adenoma who underwent 99mTc-MIBI imaging for the diagnosis of PHPT were examined. Early and delayed MIBI lesion/background ratios (eLBR and dLBR), early and delayed lesion/thyroid ratio (eLTR and dLTR), and retention index (RI) were calculated as planar dual-phase scintigraphy parameters. Adenoma volume (Svol) and parathormone (PTH)/Svol ratio were measured as SPECT/CT-derived parameters. Calcium levels exhibited a positive correlation with eLBR (r = 0.33, p < 0.001), dLBR (r = 0.29, p = 0.01), dLTR (r = 0.31, p < 0.001), and PTH/Svol (r = 0.38, p < 0.001). PTH did not correlate with planar parameters and Svol. Among the imaging parameters, only the PTH/Svol ratio showed a negative correlation with phosphorus levels (r = -0.29, p = 0.02). For predicting disease severity, the PTH/Svol ratio exhibited similar diagnostic performance to PTH and phosphorus levels but outperformed the eLBR and dLBR. Both planar and SPECT-derived parameters can provide valuable insights into the functional status of the parathyroid adenoma and the associated disease severity. PTH/Svol ratio, combining imaging and laboratory findings to provide a more comprehensive approach to patient care, could be an exciting new indicator.

A contemporary analysis of the pre- and intraoperative recognition of multigland parathyroid disease

BACKGROUND

Despite advances in biochemical and radiological identification of parathyroid gland enlargement, primary hyperparathyroidism (PHPT) due to sporadic multigland parathyroid disease (MGPD) remains a perioperative diagnostic dilemma. Failure to recognise MGPD pre- or intraoperatively may negatively impact surgical cure rates and result in persistent PHPT and ongoing patient morbidity.

METHODS

We have conducted a comprehensive review of published literature in attempt to determine factors that could aid in reliably diagnosing sporadic MGPD pre- or intraoperatively. We discuss preoperative clinical features and examine pre- and intraoperative biochemical and imaging findings concentrating on those areas that give practicing surgeons and the wider multi-disciplinary endocrine team indications that a patient has MGDP. This could alter surgical strategy.

CONCLUSION

Biochemistry can provide diagnosis of PHPT but cannot reliably discriminate parathyroid pathology. Histopathology can aid diagnosis between MGPD and adenoma, but histological appearance can overlap. Multiple negative imaging modalities indicate that MGPD may be more likely than a single parathyroid adenoma, but the gold standard for diagnosis is still intraoperative identification during BNE. MGPD remains a difficult disease to both diagnose and treat.

Influence of Vitamin D Deficiency on Cyclin D1-Induced Parathyroid Tumorigenesis

Primary hyperparathyroidism (PHPT) is a common endocrinopathy for which several pathogenic mechanisms, including cyclin D1 overexpression, have been identified. Vitamin D nutritional status may influence parathyroid tumorigenesis, but evidence remains circumstantial. To assess the potential influence of vitamin D insufficiency/deficiency on initiation or progression of parathyroid tumorigenesis, we superimposed vitamin D insufficiency or deficiency on parathyroid tumor-prone parathyroid hormone-cyclin D1 transgenic mice. Mice were placed on diets containing either 2.75 IU/g, 0.25 IU/g, or 0.05 IU/g cholecalciferol, either prior to expected onset of PHPT or after onset of biochemical PHPT. When introduced early, superimposed vitamin D insufficiency/deficiency had no effect on serum calcium or on parathyroid gland growth. However, when introduced after the onset of biochemical PHPT, vitamin D deficiency led to larger parathyroid glands without differences in serum biochemical parameters. Our results suggest that low vitamin D status enhances proliferation of parathyroid cells whose growth is already being tumorigenically driven, in contrast to its apparent lack of direct proliferation-initiating action on normally growing parathyroid cells in this model. These results are consistent with the hypothesis that suboptimal vitamin D status may not increase incidence of de novo parathyroid tumorigenesis but may accelerate growth of a preexisting parathyroid tumor.

Correlation between preoperative calcium and parathormone levels with parathyroid gland volume

Objective. Hyperparathyroidism is a prevalent disease with parathyroid adenomas being the most common cause. Surgical excision remains the standard treatment for parathyroid adenoma. Successful preoperative localization of the parathyroid adenoma could facilitate the decision regarding the extent of surgical exploration. The aim of the current study was to assess the correlation between the preoperative values of parathyroid hormone and ionized calcium with the adenoma weight and volume in patient with primary hyperparathyroidism caused by single-gland adenoma. Patients and Methods. We did this retrospective review for all patients who were diagnosed with primary hyperparathyroidism due to a solitary parathyroid adenoma in our general surgery department over 4 years. SPSS software was used to get the correlation coefficient between the peak preoperative levels of calcium and parathyroid hormone with the parathyroid adenoma weight and volume. Results. Ninety-nine patients were included into the study. The average age at surgery was 62.65±12.00 years. The correlation coefficient between the adenoma volume and weight with the preoperative ionized calcium level was weakly positive (r=0.329, p<0.01) and (r=0.281, p=0.019), respectively, while the correlation with the preoperative parathyroid hormone level was stronger (r=0.708, p<0.01) and (r=0.650, p<0.01), respectively. Conclusions. The strong positive relationship between the preoperative parathyroid hormone and calcium levels with the parathyroid adenoma size and weight can help the surgeon to predict the volume of the involved gland and avoid an unnecessary dissection.

Giant parathyroid tumours in primary hyperparathyroidism: a systematic review

PURPOSE

Giant parathyroid adenoma (GPA) can present with severe biochemical derangement similar to the clinical presentation of parathyroid carcinoma (PC). This study aims to present the current evidence on surgical management of GPAs in primary hyperparathyroidism.

METHODS

A systematic review of the literature on GPAs was conducted following the PRISMA guidelines. Data on clinical, biochemical, preoperative diagnostic, and surgical methods were analysed.

RESULTS

Sixty-one eligible studies were included reporting on 65 GPAs in eutopic, ectopic mediastinal, and intrathyroidal locations (61.5%, 30.8%, and 7.7%, respectively). A palpable neck mass was present in 58% of GPAs. A total of 90% of patients had symptoms including fatigue, skeletal pain, pathological fracture, nausea, and abdominal pain. Ninety percent of patients had significant hypercalcaemia (mean 3.51 mmol/L; range: 2.59-5.74 mmol/L) and hyperparathyroidism with PTH levels on average 14 times above the upper limit of the normal reference. There was no correlation between the reported GPA size and PTH nor between GPA weight and PTH (p = 0.892 and p = 0.363, respectively). Twenty-four percent had a concurrent thyroidectomy for suspicious features, intrathyroidal location of GPA, or large goitre. Immunohistochemistry such as Ki-67, parafibromin, and galectin-3 was used in 18.5% of cases with equivocal histology. Ninety-five percent of GPAs were benign with 5% reported as atypical adenomas.

CONCLUSION

The reported data on GPAs are sparse and heterogeneous. In GPAs with suspicious features for malignancy, en bloc resection with concurrent thyroidectomy may be considered. In the presence of equivocal histological features, ancillary immunohistochemistry is advocated to differentiate GPAs from atypical adenomas and PCs.

Distinguishing Parathyromatosis, Atypical Parathyroid Adenomas, and Parathyroid Carcinomas Utilizing Histologic and Clinical Features

Parathyromatosis is displaced parathyroid tissue in the neck and mediastinum related to prior surgery. Parathyromatosis can be difficult to distinguish from atypical adenoma and parathyroid carcinoma. The aim of this study is to evaluate clinical and morphologic features that may differentiate parathyromatosis, atypical adenoma, and parathyroid carcinoma. Cases of parathyromatosis, atypical adenoma, and parathyroid carcinoma were identified. Index cases were reviewed by consensus for histologic features, including stromal, cytologic/architectural, and invasive features. Ki67 was performed on index cases and scored using the Adsay method. Clinical information was gathered from the electronic medical record. 4 parathyromatosis, 17 atypical adenoma, and 6 parathyroid carcinoma were included. Parathyroid carcinomas were more likely to display coarse chromatin with nucleoli (P = 0.04), infiltrative invasion (P < 0.01), and metastasis (P < 0.01). Only parathyromatosis showed circumscribed invasion. Infiltrative invasion was more common in cases with progression (P = 0.046) and metastasis (P < 0.001). Necrosis and perineural invasion were only present in cases with progression and were more frequent in cases with metastasis (P = 0.079 and P = 0.19, respectively). There were no differences in presence of a fibrous capsule, capsular invasion, intralesional fibrous bands, random endocrine atypia, solid growth, Ki67 index, gland size/weight, serum PTH/calcium levels, and locoregional recurrence rates. There is overlap in the histologic features in parathyromatosis, atypical adenoma, and parathyroid carcinoma. While perineural, vascular, and infiltrative soft tissue invasion should remain diagnostic of malignancy, other atypical features such as solid growth, coarse chromatin with nucleoli, and necrosis should raise concern for recurrence and/or metastasis, and can be present in parathyroid lesions with and without recurrence.

Which biochemical and clinical parameters correlate with parathyroid adenoma weight? Turkish-Bulgarian endocrine and breast surgery study group, hyperparathyroidism registry study

BACKGROUND

Primary hyperparathyroidism (pHPT) caused by a single benign parathyroid adenoma is a common endocrine disorder that is affected by regional differences. Living in different geographical regions reveals differences in the laboratory results and pathological findings, but studies on this subject are not sufficient. The article focuses on biochemical and pathological effects of geographical differences in parathyroid adenoma. In addition, the present study seeks to elaborate on treatment methods and effectiveness of screening in geographical area of Bulgaria and Turkey.

METHOD

In this prospective study, 159 patients were included from 16 centres. Demographic characteristics, symptoms, biochemical markers and pathologic characteristics were analysed and compared between 8 different regions.

RESULTS

Patients from Turkish Black Sea had the highest median serum calcium (Ca) level, whereas patients from Eastern Turkey had the lowest median serum phosphorus (P) level. On the other hand, there was no significant difference between Ca, parathormone (PTH) and P levels according to regions. Patients from Eastern Turkey had the highest adenoma weight, while patients from Bulgaria had the lowest adenoma weight. The weight of adenoma showed statistically significant differences between regions (p < 0.001). There was a correlation between adenoma weight and serum PTH level (p = 0.05) and Ca level (p = 0.035).

CONCLUSION

This study has provided a deeper insight into the effect of the regional differences upon clinicopathological changing and biochemical values of pHTP patients with adenoma. Awareness of regional differences will assist in biochemical screening and treatment of this patient group.

Predictors of adenoma size and location in primary hyperparathyroidism

Purpose

In primary hyperparathyroidism (PHPT), intraoperative localization of the parathyroid adenoma can be challenging, especially in cases of negative preoperative imaging. Since a focused unilateral parathyroidectomy has benefits compared to a conventional bilateral neck exploration, the question arises whether adenoma size prediction can facilitate a targeted approach. We investigated whether single parathyroid adenoma size can be estimated using preoperative parathyroid hormone (PTH), calcium, and phosphate in patients with PHPT. Preoperative imaging accuracy was evaluated.

Methods

The data of 156 patients who underwent curative parathyroidectomy for single adenoma PHPT were analyzed retrospectively. Information obtained included laboratory data, imaging results, intraoperative data, and final pathology. Imaging accuracy was analyzed descriptively. The association between preoperative biochemical markers and adenoma dimensions was investigated using Spearman’s correlation coefficient and multivariable regression modeling.

Results

Cervical ultrasound correctly predicted adenoma laterality in 95.5%, sestamibi scintigraphy in 80.6%, both had lower true-positive rates for quadrant prediction. Patients with negative imaging results showed higher thyroid volumes than those with positive results. Adenoma volume was positively correlated with preoperative PTH (p < 0.001) and calcium (p < 0.001) and negatively correlated with preoperative phosphate (p = 0.001). Using these preoperative biochemical markers and patient age and BMI, adenoma volume can be significantly predicted using the multivariable regression algorithm.

Conclusion

Cervical ultrasound is superior to scintigraphy for predicting adenoma location and should be the first-choice imaging method, but both methods may be limited by increased thyroid volume. Large adenomas are more likely with higher PTH, higher calcium, and lower phosphate levels. In cases of undetermined adenoma location, an estimation of adenoma volume via our algorithm could corroborate sonographic volume measurements of the suspected adenoma.

Radioactive Parathyroid Adenomas on Sestamibi Scans: Low Parathyroid Hormone Secretory Potential and Large Volume

BACKGROUND

We investigated the clinical characteristics of parathyroid adenomas according to radioactivity on 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) single-photon emission computed tomography/computed tomography (SPECT/CT) in primary hyperparathyroidism (PHPT) patients.

METHODS

The study included 217 patients diagnosed with PHPT from 2000 to 2019 at Seoul National University Hospital who underwent 99mTc-MIBI SPECT/CT scans. On SPECT/CT, the radioactivity of parathyroid adenomas was measured as the ratio of the mean radioactivity count of the parathyroid adenoma to that of the contralateral thyroid.

RESULTS

Tumors were localized by MIBI scans in 190 patients (MIBI [+] group) and by ultrasound or parathyroid four-dimensional CT in 27 patients (MIBI [-] group). The mean age was 55 years, and mean body mass index was 23.4 kg/m2. Patients in the MIBI (+) group had higher parathyroid hormone (iPTH) and lower 25-hydroxy vitamin D levels than those in the MIBI (-) group (168.0 pg/mL [interquartile range, IQR, 111.0 to 250.7] vs. 134.7 pg/mL [IQR, 98.2 to 191.2], P=0.049; 15.4 ng/mL [IQR, 11.1 to 20.8] vs. 21.2 ng/mL [IQR, 13.9 to 24.8], P=0.012, respectively). Patients in the MIBI (+) group had larger tumor volumes, but lower iPTH/volume ratios than those in the MIBI (-) group (1,216.66 [IQR, 513.40 to 2,663.02], 499.82 mm3 [IQR, 167.77 to 1,229.80], P=0.002; 0.18 [IQR, 0.08 to 0.46], 0.40 pg/mL/mm3 [IQR, 0.16 to 1.29], P=0.016, respectively). Adenoma radioactivity was positively correlated with calcium, iPTH, and volume (r=0.180, P=0.020; r=0.208, P=0.006; r=0.288, P<0.001, respectively), but not with iPTH/volume.

CONCLUSION

Parathyroid adenomas with positive MIBI scans had larger volumes and higher iPTH than adenomas with negative scans, but lower iPTH per unit volume.

Correlation of perioperative biochemical variables with single adenoma weight in patients with primary hyperparathyroidism

BACKGROUND

Single parathyroid adenoma is the main cause of primary hyperparathyroidism (PHPT), with surgery remaining the gold standard for its treatment. The ability to preoperatively predict the parathyroid adenoma size and could facilitate the decision about the extent of surgical exploration. It is reasonable to hypothesize that the perioperative levels of PHPT-related variables (i.e. calcium, parathormone, phosphate) may predict the adenoma weight or/and demonstrate whether the adenoma is successfully removed or not. Aim of this study is to explore the relationship between perioperative biochemical values and adenoma weight. Secondarily, we investigated the relationship between adenoma weight and uni-/bilateral neck exploration.

METHODS

Retrospective study of all patients undergone surgery for primary hyperparathyroidism due to single adenoma in a tertiary university hospital in Germany during a 6-year period. Following variables were analyzed: preoperative serum calcium, phosphorus and parathormone, intraoperative parathormone before and after adenoma excision, intraoperative PTH decrease, postoperative serum calcium and parathormone (PTH_postop-pg/ml), calcium and PTH decrease. Bivariate correlations were calculated by the Spearman's correlation test at the 95% significance level.

RESULTS

A total of 339 patients were included in the study. The median age of the patients was 60 years (range 21-90) and 77% were females. The median adenoma weight was 1 g (range 0.1-11). Adenoma weight correlated strong with maximum adenoma diameter (r = 0.72, p < 0.05), moderate with preoperative parathormone (r = 0.44) and parathormone decrease (r = 0.27), whereas there was no correlation with the intraoperative PTH decrease (r = 0.02). There was also a borderline (moderate to weak) correlation with pre- and postoperative calcium levels (r = 0.21 and r = 0.23 respectively) and a negative borderline correlation with phosphorus (r = - 0.21). Patients who required bilateral neck exploration, had significantly lighter adenomas (median weight 0.8 g vs 1.1 g, p = 0.005).

CONCLUSIONS

We conclude that preoperative PTH levels may only serve as an approximate guide to adenoma weight, as direct preoperative prediction is not possible. Serum calcium levels, PTH and calcium decrease correlate only weak with adenoma weight. Patients who require bilateral neck exploration, have significantly (20-25%) lighter adenomas.

OCCULT PRIMARY HYPERPARATHYROIDISM: A CASE REPORT AND REVIEW OF PARATHYROID ULTRASONOGRAPHY

Objective

To discuss the diagnosis and management of occult primary hyperparathyroidism.

Methods

We present the biochemical and radiologic evaluation, treatment, and outcome of a woman with occult primary hyperparathyroidism which presented as an unusual neck mass on ultrasound. We also present a relevant literature review.

Results

A 52-year-old female presented with Hashimoto thyroiditis and a 1.2-cm, hypoechoic oval nodule in the left upper lateral portion of the thyroid. She returned a decade later with a 2.2-cm, hypervascular mass on ultrasound. Parathyroid hormone was mildly elevated at 90 pg/mL (reference range is 15 to 65 pg/mL), but she had persistently normal levels of total serum calcium at 9.9 mg/dL (reference range is 8.7 to 10.3 mg/dL), phosphorus at 3.5 mg/dL (reference range is 2.1 to 4.5 mg/dL), and albumin at 4.4 g/dL (reference range is 3.6 to 4.8 g/dL). She had elevated ionized calcium of 5.9 mg/dL (reference range is 4.5 to 5.6 mg/dL). Computed tomography with contrast of the neck revealed an enhancing oval lesion abutting the superior pole of the left thyroid with attenuation characteristics similar though slightly different from the thyroid. 99mTc-Sestamibi scan showed increased uptake posterior to the superior aspect of the left thyroid. Bone densitometry showed osteoporosis of the left distal radius and osteopenia of the left femoral neck. Minimally invasive radio-guided parathyroidectomy was performed with normalization of parathyroid hormone. Pathology confirmed a 1.715-g parathyroid adenoma.

Conclusion

Despite normal total calcium levels, clinically significant primary hyperparathyroidism may present as a large adenoma which could appear as a hypervascular neck mass on ultrasound. A high index of suspicion based on ultrasound features and measurement of ionized calcium may be helpful in diagnosing occult, but clinically relevant primary hyperparathyroidism.

Predictors of early postoperative hypocalcemia after total parathyroidectomy in renal hyperparathyroidism

Purpose

Patients with secondary hyperparathyroidism are at high risk for developing postoperative hypocalcemia. However, there are limited data regarding predictors of postoperative hypocalcemia in renal failure patient with secondary hyperparathyroidism. This study aimed to determine the clinical presentations of renal hyperparathyroidism and the predictors of early postoperative hypocalcemia after total parathyroidectomy.

Methods

Data of patients with renal hyperparathyroidism who underwent total parathyroidectomy between January 2007 to December 2014 were reviewed retrospectively. Patients were divided into 2 cohort groups according to their serum calcium levels within 24 hours of parathyroidectomy: the hypocalcemia group (calcium levels of 2 mmol/L or less), and the normocalcemia group (calcium levels more than 2 mmol/L). With the use of multivariable logistic regression analyses, the predictors of early postoperative hypocalcemia after total parathyroidectomy in patients with renal hyperparathyroidism were investigated.

Results

Among 68 patients, 56 patients (82.4%) were symptomatic preoperatively. Fifty patients (73.5%) presented with bone pain and 14 patients (20.6%) had muscle weakness. Early postoperative hypocalcemia occurred in 25 patients (36.8%). Preoperative alkaline phosphatase level was the predictor of early postoperative hypocalcemia (adjusted odds ratio, 1.004; 95% confidence interval, 1.001–1.006; P = 0.002).

Conclusion

Results from our study show that most of the patients with renal hyperparathyroidism were symptomatic preoperatively and the most common clinical presentations were bone pain and muscle weakness. The significant predictor of early postoperative hypocalcemia after total parathyroidectomy was the preoperative alkaline phosphatase levels.

Can we predict expected adenoma weight preoperatively with reference to the correlation of preoperative biochemical tests with parathyroid adenoma weight?

BACKGROUND

Primary hyperparathyroidism is a prevalent disease with proven benefits for appropriately selected patients who undergo parathyroidectomy. The ability to accurately predict expected single adenoma gland weight as the cause based on preoperative biochemical tests could improve cure rates in a minimally invasive approach.

OBJECTIVE

To assess the correlation between parathyroid weight and preoperative parathyroid hormone and calcium levels in patients with primary hyperparathyroidism with a solitary adenoma and determine if these could be used to predict expected parathyroid weight.

METHODS

Patients with primary hyperparathyroidism who underwent curative parathyroidectomy from 2013 to 2018 was retrospectively analysed.

RESULTS

There is a strong positive correlation r = 0.602 between preoperative PTH levels with respect to parathyroid weight (p < 0.001). There was a moderate correlation r = 0.474 between preoperative adjusted Calcium and PTH weight (p < 0.001). An algorithm was developed to calculate predicted weight of a single adenoma but when tested against cases with hyperplasia and double adenomas during the period, the variability of predicted weight meant it was impossible to differentiate between the causes. Hyperplasia was excluded and 95% of double adenomas excluded however, when parathyroid weight exceeded 1200 mg CONCLUSION: There is a strong correlation between preoperative PTH levels and calcium levels with parathyroid weight. The large variability of predicted parathyroid weight however, precludes the use of biochemical tests alone preoperatively in being able to differentiate between a single adenoma, double adenoma or hyperplasia as the cause in primary hyperparathyroidism. At parathyroid predicted weights above 1200 mg however, all cases of hyperplasia, and 95% of double adenomas excluded.

Dwarfs and Giants of Parathyroid Adenomas-No Difference in Outcome After Parathyroidectomy

BACKGROUD

This study compares the outcome of parathyroidectomy for primary hyperparathyroidism (PHPT) in patients whose adenomas' weights were at the extremes of the distribution curve. As the size of parathyroid adenomas influences the success rate of localization studies for PHPT, it is possible that a difference in cure rate could be observed between subgroups of patients.

MATERIALS AND METHODS

Data were retrieved from a prospective database maintained in a large university hospital.

RESULTS

From a cohort of 519 patients who underwent parathyroidectomy for PHPT, two subgroups of patients were identified based on the extreme 10% of the distribution curve for adenomas' weight: adenomas <300 mg ("dwarfs", n = 100, median 200 mg) and >3000 mg ("giants", n = 56, median 4300 mg). In comparison with giant adenomas, dwarf adenomas were associated with less severe hypercalcemia (median 2.84 versus 3.00 mmol/L, P < 0.001) and lower PTH (median 11.7 versus 25.6 pmol/L, P < 0.001). The occurrence of dwarf adenomas showed no trend during the study period (23/173 [13%] in 2000-2004 versus 36/217 [17%] in 2007-2011). Scan-directed parathyroidectomy was feasible in more patients with giant adenomas (59% versus 38%). Persistent disease was diagnosed in three patients with dwarf adenomas. Patients with giant adenomas had no recurrence during a follow-up of 40 mo even though eight patients had histological features suggestive of atypical/malignant tumors.

CONCLUSIONS

Preoperative biochemistry is a poor predictor of adenomas' size even at the extremes of the distribution curve. Cure can be achieved in all patients with "dwarf" adenomas. Even in the presence of suspicious histological features, "giant" adenomas did not show malignant behavior.

Presentation, diagnostic assessment and surgical outcomes in primary hyperparathyroidism: a single centre's experience

OBJECTIVE

Primary hyperparathyroidism (PHPT) is a common reason for referral to endocrinology but the evidence base guiding assessment is limited. We evaluated the clinical presentation, assessment and subsequent management in PHPT.

DESIGN

Retrospective cohort study.

PATIENTS

PHPT assessed between 2006 - 2014 (n = 611) in a university hospital.

MEASUREMENTS

Symptoms, clinical features, biochemistry, neck radiology and surgical outcomes.

RESULTS

Fatigue (23.8%), polyuria (15.6%) and polydipsia (14.9%) were associated with PHPT biochemistry. Bone fracture was present in 16.4% but was not associated with biochemistry. A history of nephrolithiasis (10.0%) was associated only with younger age (P = 0.006) and male gender (P = 0.037). Thiazide diuretic discontinuation was not associated with any subsequent change in calcium (P = 0.514). Urine calcium creatinine clearance ratio (CCCR) was <0.01 in 18.2% of patients with confirmed PHPT. Older age (P < 0.001) and lower PTH (P = 0.043) were associated with failure to locate an adenoma on ultrasound (44.0% of scans). When an adenoma was identified on ultrasound the lateralization was correct in 94.5%. Non-curative surgery occurred in 8.2% and was greater in those requiring more than one neck imaging modality (OR 2.42, P = 0.035).

CONCLUSIONS

Clinical features associated with PHPT are not strongly related to biochemistry. Thiazide cessation does not appear to attenuate hypercalcaemia. PHPT remains the likeliest diagnosis in the presence of low CCCR. Ultrasound is highly discriminant when an adenoma is identified but surgical failure is more likely when more than one imaging modality is required.

Management and outcomes of hyperparathyroidism: a case series from a single institution over two decades

Background

Hyperparathyroidism is a frequent endocrine disorder with variable clinical manifestations and outcomes. We aimed to evaluate clinical presentations, management and outcomes of hyperparathyroidism.

Methods

A retrospective study was conducted to include all patients presented with hyperparathyroidism between 1995 and 2014 at a single tertiary hospital with an average follow-up period of 46 months. Data were reviewed for clinical presentations, diagnostic work-up, intraoperative findings, management, and outcomes.

Result

We identified 161 patients with hyperparathyroidism; 69% were females and the mean age was 49.4±15 years. Patients presented mainly with musculoskeletal (65.8%), renal (37.3%), gastrointestinal tract (53.8%) and neuropsychiatric (8.8%) manifestations. At presentation, mean serum calcium and parathyroid hormone levels were elevated while mean vitamin D level was lower. Sestamibi-^99mTc (MIBI) scintigraphy was done for 134 patients (83.2%) and was positive in 94 (70%). Primary hyperparathyroidism (67.7%) was the most frequent diagnosis followed by secondary (29.8%) and tertiary hyperparathyroidism (2.5%). The frequent indication for surgery was hypercalcemia (67.3%), bone disease (35.6%) and renal calculi (28.9%). The main postoperative pathology was parathyroid adenoma (63.1%) followed by hyperplasia (37.3%). Fourteen (8.9%) and 18 (11.4%) patients had persistent and recurrent hyperparathyroidism, respectively. Autotransplantation of parathyroid tissue was done in 36 cases.

Conclusion

Primary hyperparathyroidism is the most frequent cause of the parathyroid disease. Parathyroidectomy is the effective surgical approach in symptomatic patients. Further studies are needed to establish the association between vitamin D levels, renal disorders and persistent or recurrent hyperparathyroidism.

Imaging of the thyroid and parathyroid using a cardiac cadmium zinc telluride camera: Phantom studies

Purpose: Cadmium zinc telluride (CZT) detectors have recently been introduced to the field of clinical nuclear cardiology. However, the feasibility of using them for organs other than the heart remains unclear. The aim of this study was to evaluate the potential of a cardiac CZT camera to acquire thyroid and parathyroid images. We used custom-made phantoms and the currently available standard protocols for CZT, instead of a sodium-iodine scintillation (NaI) camera. Materials and Methods: Thyroid phantoms with or without parathyroid adenomas were made from agar using radiopharmaceuticals (99mTc or 123I) and imaged using CZT and NaI cameras. Using the CZT camera data, we prepared maximum intensity projection (MIP) images and planar equivalent (PE) images. Image counts were compared to those from the NaI camera, and the radioactivity of the phantoms was measured. For parathyroid imaging, three different protocols with the NaI camera were tested using MIP images. Results: For thyroid imaging, MIP could provide images as clear as those obtained from the NaI camera. The radioactivity and image counts correlated better for the PE images than the MIP images, especially for 123I images. We succeeded in obtaining clear parathyroid adenoma images from MIP images using all three protocols. Conclusion: A cardiac CZT camera can effectively perform qualitative and quantitative assessments of the thyroid and parathyroid organs.

Regional Clinical and Biochemical Differences among Patients with Primary Hyperparathyroidism

Background:

Environmental habitat may play a role in clinical disparities of primary hyperparathyroidism (pHPT) patients.

Aims:

To compare preoperative clinical symptoms and associated conditions and surgical findings in patients with pHPT, living in different geographical regions from the Black Sea, Mediterranean and Anatolia regions.

Study Design:

Retrospective, clinical-based multi-centric study of 694 patients with pHPT.

Methods:

Patients from 23 centers and 8 different geographical regions were included. Data related to baseline demographics, clinical, pathologic and treatment characteristics of 8 regions were collected and included age, gender, residential data, symptoms, history of fracture, existence of brown tumor, serum total Ca and p levels, serum parathormone (PTH) levels, serum 25-OH vitamin D levels, bone mineral density, size of the resected abnormal parathyroid gland(s), histology, as well as the presence of ectopia, presence of dual adenoma, and multiple endocrine neoplasia (MEN)- or familial-related disease.

Results:

The median age was 54. Asymptomatic patient rate was 25%. The median PTH level was 232 pg/mL and serum total Ca was 11.4 mg/dL. Eighty-seven percent of patients had an adenoma and 90% of these had a single adenoma. Hyperplasia was detected in 79 patients and cancer in 9 patients. The median adenoma size was 16 mm. Significant parameters differing between regions were preoperative symptoms, serum Ca and p levels, and adenoma size. All patients from South-East Anatolia were symptomatic, while the lowest p values were reported from East Anatolia and the largest adenoma size, as well as highest Ca levels, were from Bulgaria.

Conclusion:

Habitat conditions vary between geographical regions. This affects the clinicopathological features of patients with pHPT.

Molecular Characteristics of Large Parathyroid Adenomas

INTRODUCTION

The clinical entity of large parathyroid adenomas (LPTAs) has not been well defined. It is speculated that LPTAs would have biochemical, histological, and molecular characteristics different from small adenomas. Our study aimed to find out occurrence of atypia and carcinomas in large parathyroid lesions and the presence of distinct molecular abnormalities in LPTAs.

MATERIALS AND METHODS

We divided the parathyroid lesions into large (>7 g, i.e., LPTAs) and small (<7 g) adenomas. We performed parafibromin, APC (adenomatous polyposis coli), galectin 3, and PGP9.5 (protein gene product 9.5) analysis by immunohistochemistry in adenomas without atypia, atypical adenomas, and carcinomas.

RESULTS

Mean serum calcium, alkaline phosphatase, and intact PTH were significantly higher in large parathyroid tumor group. The presence of both atypical adenoma and carcinoma was higher in large parathyroid tumor group. There was higher percentage of atypia in patients with LPTAs >10 g (33%), and 68% of tumors showed at least one marker suggestive of malignancy in this group. Detailed analysis of immunohistochemical features of LPTA >10 g revealed that six patients showed complete loss of parafibromin immunoreactivity (out of these four showed atypia), while seven showed partial loss. In histopathologically proven malignancy (n = 9), six patients showed complete loss of parafibromin staining, 5 (55%) APC negativity, and 45% showed both galectin 3 and PGP9.5 positivity. Three out of these showed all IHC markers s/o malignancy, and all of them had evidence of metastases or recurrence. 32% of atypical adenoma and 13% of atypical adenoma showed complete loss of parafibromin staining, however none developed metastases or recurrence in follow-up (median follow-up 40 months). Loss of parafibromin staining (complete or partial) was higher in LPTA group (56%) than that in small adenoma (39%); however, it was not statistically significant. APC, galectin 3, and PGP9.5 markers suggestive were higher in LPTA group but were not significant.

CONCLUSION

LPTAs may show some morphological and immunohistochemical features suggestive of malignancy and can be considered a separate entity. However, the immunohistochemical markers are unable to clearly segregate those LPTAs that may show premalignant potential. Further, we would like to recommend that LPTAs showing complete parafibromin loss together with atypia should be kept under close follow-up.

Surgery for parathyroid microadenomas: patient characteristics, localization success and operative cures

BACKGROUND

In recent years, patients with primary hyperparathyroidism (PHPT) are being diagnosed earlier, with milder elevations in parathyroid hormone (PTH) and serum calcium. We aimed to investigate whether adenoma size reflects biochemical severity of presentation and influences localization of pre-operative scans.

METHODS

A total of 630 consecutive patients undergoing parathyroidectomy for PHPT were recruited into either the microadenoma (≤200 mg) or macroadenoma (>200 mg) group. Pre-operative serum calcium, PTH, rates of minimally invasive parathyroidectomy and bilateral neck exploration, localization of adenomas with pre-operative ultrasound and sestamibi (MIBI) scans, cure rates and other demographic parameters were compared. The data were analysed using Student's t-test, Chi-squared test, linear and multiple regression analyses.

RESULTS

Patients in the microadenoma group had significantly lower pre-operative serum calcium (P < 0.001) and PTH (P < 0.001), less accurate MIBI (P < 0.001) and ultrasound (P < 0.001), lower cure rates (P = 0.04) and were more likely to undergo bilateral neck exploration (P = 0.001). However, multivariate analysis revealed that microadenomas are most strongly associated with the findings of less accurate MIBI (P = 0.03) and lower pre-operative calcium (P = 0.04).

CONCLUSION

In conclusion, smaller adenomas are strongly associated with biochemically milder PHPT and less accurate localization studies. Therefore, microadenomas continue to present as a challenge in both diagnosis and management.

Parathyroid 4D CT and Scintigraphy

Objective

To determine the prevalence of missed lesions for parathyroid 4-dimensional computed tomography (4D CT) and scintigraphy and to describe the factors leading to missed lesions for both modalities.

Study Design

Case series with chart review.

Setting

Single center, hospital based.

Subjects and Methods

Forty patients undergoing 4D CT and scintigraphy before parathyroidectomy between July 2009 and October 2013 were included. Radiology reports and imaging were reviewed and correlated with operative notes to identify cases with missed lesions and the reasons for those misses. All lesions were then classified according to the following factors: multigland disease, lesion size, patient body weight, and multinodular goiter.

Results

Of the 40 patients, 6 had multigland disease, resulting in 51 lesions; 12 and 29 lesions were missed on 4D CT and scintigraphy, respectively. The sensitivity for detection of all lesions was 76% for 4D CT and 43% for scintigraphy. Sensitivities for single-gland disease were 88% for 4D CT and 50% for scintigraphy. Sensitivities for multigland disease were 53% for 4D CT and 24% for scintigraphy. Rates of multigland disease in patients with missed lesions were 75% on 4D CT and 48% on scintigraphy, as compared with patients with detected lesions, 23% and 18%, respectively ( P ≤ .04). Mean weight of lesions missed on 4D CT was 0.3 and 0.6 g in detected lesions ( P = .15). Mean weight of lesions missed on scintigraphy was 0.4 and 0.8 g in detected lesions ( P = .03).

Conclusion

4D CT has higher sensitivity than scintigraphy. Missed lesions are more likely to occur with multigland disease for both modalities and in smaller lesions for scintigraphy.

Parathyroid Hormone as a Marker for Predicting the Severity of Hypocalcaemia Following Parathyroidectomy

The purpose of this study is to determine preoperative predictors of the severity of the hypocalcaemia following parathyroidectomy. The case records of 70 patients who underwent parathyroidectomy for primary hyperparathyroidism from 2000 to 2013 was retrospectively studied. Their symptoms at presentation, biochemical parameters serum calcium, parathyroid hormone, alkaline phosphatase and parathyroid size on ultrasound were compared with their serial post-operative serum calcium levels at 24, 48, 72 and 96 h. For the purpose of analysis, patients were divided into three groups. Group 1-asymptomatic, biochemically normal (serum calcium always ≥8.5 mgs%); Group 2-asymptomatic, biochemically below normal (at least one reading <8.5, but none <8.0); Group 3-symptomatic (any one reading <8.0). No correlation was found between the severity of the presenting symptoms, pre-operative serum calcium levels or the parathyroid size with the post-operative calcium levels in the three groups. Though preoperative serum alkaline phosphatase levels were higher in Group 3, it was not statistically significant (p = 0.069). However, preoperative serum parathyroid hormone levels significantly correlated with postoperative serum calcium levels in all three groups (p = 0.006). Pre-operative serum parathyroid hormone levels may serve as a marker for severe post-operative hypocalcaemia and thus identify patients requiring closer monitoring and longer hospitalization following parathyroidectomy.

Ultrasonographic evaluation of parathyroid hyperplasia in multiple endocrine neoplasia type 1: Positive correlation between parathyroid volume and circulating parathyroid hormone concentration

There are few reports on parathyroid ultrasonography of multiple endocrine neoplasia type 1 (MEN1). This study investigated the ultrasonographic features of parathyroid glands in 10 patients with MEN1 who underwent preoperative neck ultrasonography and parathyroidectomy between 2006 and 2010 at Toranomon Hospital. We retrospectively analyzed clinical features, laboratory and ultrasonographic data, and pathological diagnosis. A total of 38 parathyroid glands were surgically removed (three to five glands from each patient). All removed parathyroids were pathologically diagnosed as hyperplasia. Seven cases (70.0 %) had adenomatous thyroid nodules. Twenty-five enlarged parathyroid glands (65.8 %) were detected by preoperative ultrasonography with a detection rate of 81.8 % (9/11) and 59.3 % (16/27) for patients without and with adenomatous nodules, respectively. Total parathyroid gland weight and potentially predictable total parathyroid volume by preoperative ultrasonography were significantly correlated with preoperative serum intact parathyroid hormone (iPTH) concentration (R = 0.97, P < 0.001 and R = 0.96, P < 0.001, respectively). The equation used for prediction of the total volume by ultrasonography was 15 × iPTH (pg/ml) - 1,000 and that for total weight was 20 × iPTH (pg/ml) - 1,400. Although adenomatous nodules often coexisted with MEN1 and made identification of enlarged parathyroid glands by ultrasonography difficult, the positive correlation between the predictable parathyroid volume by ultrasonography and serum iPTH suggests that their measurement is useful in the preoperative detection and localization of enlarged parathyroid glands in patients with MEN1. Furthermore, the presence of parathyroid glands that should be resected can be predicted before surgery using the equation proposed here.

The value of intraoperative PTH measurements in patients with mild primary hyperparathyroidism

PURPOSE

Intraoperative parathyroid hormone (ioPTH) measurement has facilitated a move to minimally invasive parathyroidectomy. Patients are referred for surgery earlier with milder hypercalcaemia and smaller tumours. Whilst previous research has shown that glands size can affect ioPTH kinetics in patients with multiple gland disease, the dynamics of ioPTH in patients with mild hyperparathyroidism (HPT) has not been studied. We therefore investigated the relationship between biochemical parameters and parathyroid adenoma weight, and determined the dynamics and accuracy of ioPTH assay in patients with milder hypercalcaemia undergoing parathyroidectomy.

METHODS

Patients undergoing parathyroidectomy for single gland disease from January 2004 to March 2011 were divided prospectively into two groups according to preoperative serum calcium: patients with a preoperative calcium ≥ 2.85 mmol/L (11.4 mg/dL) and <2.85 mmol/L were grouped as severe and mild hypercalcaemia, respectively. Correlation coefficients were calculated to assess the relationship between biochemical markers of calcium homeostasis and ioPTH measurements with respect to parathyroid gland weight.

RESULTS

There was a weak correlation of preoperative serum calcium (r = 0.248, r = 0.207), PTH (r = 0.392, r = 0.275), and baseline ioPTH (r = 0.516, r = 0.244) with parathyroid gland weight in severe (n = 113) and mild groups (n = 190), respectively. No correlation between the magnitude in ioPTH drop with parathyroid gland weight at 5 or 10 min post-excision for either group was observed. Success rates (post-operative normocalcaemia) were similar for each group (99.1 % severe, 98.9 % mild).

CONCLUSION

This prospective study provides evidence that ioPTH assay is a valuable tool in predicting adequate tissue removal in patients with milder and more severe hypercalcaemia due to single gland primary HPT.

Correlation of biochemical markers of primary hyperparathyroidism with single adenoma weight and volume

Preoperative laboratory markers of primary hyperparathyroidism including serum parathormone (PTH), calcium and phosphate level may have some predictive value about the size and volume of the abnormal parathyroid gland tissue which needs to be resected in primary hyperparathyroidism. In a Prospective study from 2003 to 2010, 69 patients with parathyroid adenoma were enrolled. The correlation between preoperative serum PTH, calcium and phosphate level with adenoma's weight and volume was analyzed separately. Adenoma volume was calculated via an equation for the volume of a spheroid object. The data were analyzed via a multiple analysis of variance, and a correlation coefficient was calculated. The level of significance was set at p _ .05. There was a significant correlation between adenoma weight and serum calcium and parathormone levels (p = .0001 and p = .0001, respectively). There was no significant correlation between adenoma weight and serum phosphate. With respect to adenoma weight, there was a significant relationship with parathormone levels and serum calcium (p = .0001 and p = .0001, respectively). There was no significant relationship between serum phosphate and aden2oma weight. Preoperative serum PTH and calcium levels may be valuable in predicting parathyroid adenoma volume and weight in primary hyperparathyroidism for a single adenoma.

Preoperative predictive factors for parathyroid carcinoma in patients with primary hyperparathyroidism

This study was conducted to review the clinical characteristics of parathyroid carcinoma (PC) and to evaluate potential preoperative predictive factors for PC in patients with primary hyperparathyroidism (PHPT). We performed a retrospective review of electronic medical records of 194 patients with pathologically confirmed PHPT in affiliated teaching hospitals of Seoul National University from January 2000 to March 2011. Adenoma was diagnosed in 171 patients, hyperplasia in 12, and carcinoma in 11. Several biochemical measurements were higher in patients with PC than in patients with benign disease, including serum total calcium (P < 0.001), intact parathyroid hormone (P = 0.003), and alkaline phosphatase (ALP) (P < 0.001). Tumors were larger in PC than in benign disease (P < 0.001). Multivariate analysis revealed that serum ALP level (P < 0.001) and tumor size were associated with PC (P = 0.03). Tumor size and serum ALP level were evaluated as preoperative predictive factors for PC using ROC analyses: a tumor size of 3.0 cm (sensitivity 90.9%, specificity 92.1%) and serum ALP level of 285 IU/L (83.3%, 97.0%) had predictive value for the diagnosis of PC in patients with PHPT. In conclusion, elevated serum ALP and a large parathyroid mass at the time of diagnosis can be helpful to predict PC in patients with PHPT.

Genetic characterization of large parathyroid adenomas

In this study, we genetically characterized parathyroid adenomas with large glandular weights, for which independent observations suggest pronounced clinical manifestations. Large parathyroid adenomas (LPTAs) were defined as the 5% largest sporadic parathyroid adenomas identified among the 590 cases operated in our institution during 2005-2009. The LPTA group showed a higher relative number of male cases and significantly higher levels of total plasma and ionized serum calcium (P<0.001). Further analysis of 21 LPTAs revealed low MIB1 proliferation index (0.1-1.5%), MEN1 mutations in five cases, and one HRPT2 (CDC73) mutation. Total or partial loss of parafibromin expression was observed in ten tumors, two of which also showed loss of APC expression. Using array CGH, we demonstrated recurrent copy number alterations most frequently involving loss in 1p (29%), gain in 5 (38%), and loss in 11q (33%). Totally, 21 minimal overlapping regions were defined for losses in 1p, 7q, 9p, 11, and 15q and gains in 3q, 5, 7p, 8p, 16q, 17p, and 19q. In addition, 12 tumors showed gross alterations of entire or almost entire chromosomes most frequently gain of 5 and loss of chromosome 11. While gain of 5 was the most frequent alteration observed in LPTAs, it was only detected in a small proportion (4/58 cases, 7%) of parathyroid adenomas. A significant positive correlation was observed between parathyroid hormone level and total copy number gain (r=0.48, P=0.031). These results support that LPTAs represent a group of patients with pronounced parathyroid hyperfunction and associated with specific genomic features.

Large parathyroid tumors have an increased risk of atypia and carcinoma

BACKGROUND

Risk for atypia and carcinoma in large parathyroid tumors is not known. Atypia and carcinoma were determined in small (<2 g) and large (≥2 g) tumors in patients undergoing parathyroidectomy for primary hyperparathyroidism.

METHODS

The study was a retrospective analysis of a 5-year prospective database. Tumor weight, histopathology, age, gender, calcium, and parathyroid hormone levels were registered. Patients with 4-gland disease were not included.

RESULTS

Among 353 parathyroid tumors, 313 weighed <2 g and 40 weighed ≥2 g. There was no difference in age between groups. Patients with large tumors were more frequently men and had higher calcium and parathyroid hormone levels. Atypia was found in 4 of 313 (1.3%) and 7 of 40 (17.5%) small and large tumors, respectively (P < .05). Corresponding figures for carcinoma were 1 of 313 (.3%) and 2 of 40 (5.0%) (P < .05).

CONCLUSIONS

Large parathyroid tumors have increased risk for atypia and carcinoma. Even so, most large parathyroid tumors are benign.

Predictors of early postoperative hypocalcemia in hemodialysis patients with secondary hyperparathyroidism

We sought to investigate predictors of early development of postoperative hypocalcemia in secondary hyperparathyroidism. Thirty-six hemodialysis patients (21 men, 15 women; mean age, 39.6 +/- 13.2 years; mean hemodialysis duration, 77.9 +/- 47.1 months) underwent parathyroidectomy. We recorded preoperative adjusted serum calcium (Ca(+2)), phosphate, alkaline phosphatase, intact parathyroid hormone, and hemoglobin levels; mean systolic and diastolic blood pressure levels; parathyroid ultrasonography and scintigraphic data; and number and weight of the resected adenomas. Patients were divided into two groups based on Ca(+2) levels within 24 hours of parathyroidectomy: the hypocalcemia group (serum Ca(+2) levels < or = 8 mg/dL; n = 26 patients) and the normocalcemia group (>8 mg/dL; n = 10 patients). A total parathyroidectomy with autotransplant was performed in 23 patients and a subtotal parathyroidectomy in 13 patients. Age (36.0 +/- 9.7 vs 49.2 +/- 16.6 years; P = .006); levels of preoperative serum Ca(+2) (9.6 +/- 0.7 vs 10.4 +/- 1.1 mg/dL; P = .01), alkaline phosphatase (346.7 +/- 354.7 vs 653.3 +/- 553.7 mg/dL; P = .05), and hemoglobin (10.5 +/- 1.4 vs 12.3 +/- 2.5 g/dL; P = .009); and number (2.0 +/- 1.3 vs 2.9 +/- 0.9; P = .04) and weight (1.9 +/- 2.1 vs 3.2 +/- 1.7; P = .01) of excised parathyroid adenomas were significantly lower among the hypocalcemia than the normocalcemia group. Among hemodialysis patients with secondary hyperparathyroidism, age, levels of preoperative serum Ca(+2) and alkaline phosphatase, and number and weight of adenomas were associated with early development of postoperative hypocalcemia.

Utility of intraoperative PTH for primary hyperparathyroidism due to multigland disease

BACKGROUND

Surgical resection is the only curative therapy for patients with primary hyperparathyroidism (1HPT). Although cure rates of parathyroidectomy are generally high, failure is most often due to unrecognized multigland disease (MGD), which compromises 15-20% of patients with 1HPT. The use of intraoperative PTH (ioPTH) monitoring is well established for single-gland disease. Controversy remains over the utility of ioPTH in MGD, with concern for false-positive results leading to prematurely concluding the operation and leaving behind abnormal parathyroid tissue, risking future recurrence. The aim of this study was to determine the utility of ioPTH monitoring for MGD.

METHODS

Between November 2000 and March 2008, data were prospectively collected on 755 patients with 1HPT who underwent parathyroidectomy. PTH samples were collected pre-incision, and then at 5, 10, and 15 min after excision of suspected abnormal parathyroid gland(s). Surgical cure was defined as a drop of greater than 50% in PTH level. Patients were clinically cured if they became normocalcemic postoperatively and remained so for 6 months. The data were analyzed to determine how accurately ioPTH predicted success or failure of parathyroidectomy.

RESULTS

Of the 755 patients, 163 (21.5%) were found to have MGD on pathology. Intraoperative PTH monitoring was used in 161 of these cases. In 146/161 cases (90.7%), the ioPTH level fell by at least 50% after removal of all suspected abnormal glands. All of these patients (100%) remained normocalcemic postoperatively. In 15/161 cases (9.3%), the PTH level did not fall by >50%. For 11/15 cases (73%), patients remained hypercalcemic postoperatively or had recurrence. However, in the remaining four cases, the patients became normocalcemic postoperatively despite failure of the PTH to fall by >50%. In each of these patients, PTH levels fell by 40-50%.

CONCLUSIONS

ioPTH monitoring accurately predicted success or failure of parathyroidectomy in 97.5% (157/161) of patients with MGD. A fall of ioPTH by >50% can be used as a highly accurate predictor of cure in patients with MGD. Therefore, ioPTH monitoring is a very useful tool in patients with 1HPT and MGD.

Predictors of intra-operative parathyroid hormone decline in subjects operated for primary hyperparathyroidism by minimally invasive parathyroidectomy

BACKGROUND

The predictors of intra-operative PTH (IOPTH) decline during minimally invasive parathyroidectomy (MIP) for primary hyperparathyroidism have been but poorly studied.

MATERIALS AND METHODS

This retrospective study included 108 patients who underwent MIP for a single adenoma. Serum calcium and phosphorus were measured before surgery and 1 day post-operatively. IOPTH was measured before (intra-operative preincision or PTHt0) and 10 min after removal of the adenoma (PTHt10). The Modification of Diet in Renal Disease (MDRD) equation was used to estimate the glomerular filtration rate. The weight of the adenoma was assessed in all the subjects.

RESULTS

The sex ratio female/male was 5.37 with a mean age of 57.3 yr. The mean pre- and postoperative values were for calcium 2.80 and 2.19 mmol/l, respectively (p<0.0001) and for phosphorus 0.90 and 1.16 mmol/l, respectively (p<0.0001). The PTH dropped from a mean value of 184.8 to 50.8 pg/ml 10 min after adenoma resection with a mean drop of 69.7%. Thirteen patients (12%) did not achieve a PTH fall of more than 50%. In a bivariate analysis, age, an MDRD<60 ml/min and weight of adenoma were inversely associated with IOPTH fall (p=0.009, p=0.004, and p<0.001, respectively) while gender, body mass index, hypertension, diabetes, pre-operative phosphorus and calcium had no significant effects. In the multivariate analysis, age, weight of adenoma, and MDRD were still independent negative predictors of the IOPTH fall (p=0.01, p=0.018, and p<0.001, respectively).

CONCLUSION

Our results suggest that during MIP the presence of a parathyroid adenoma with a high weight, in an elderly subject or in a subject with altered renal function, will result in a lesser degree of IOPTH fall.