Surgical Treatment Of Primary Hyperparathyroidism Research Articles

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

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

Surgical treatment of primary hyperparathyroidism with ectopic parathyroid adenoma in the mediastinum

The paper presents a rare clinical case of a 36-year-old female patient with primary hyperparathyroidism (PHPT) and an ectopic parathyroid adenoma (EPA) in the mediastinum. Ectopic parathyroid adenoma in the mediastinum is found in 1–2% of cases. This is an extremely rare atypical localization as compared with many other possible uncommon locations. Thoracoscopic resection of the adenoma was performed. Pathohistological examination of the postoperative specimen confirmed the preliminary diagnosis. The specimen revealed typical parathyroid adenoma. On the seventh day after surgical treatment the patient was discharged in satisfactory condition.

Surgical treatment for Primary hyperparathyroidism in ederly patient

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Abstract #1408170: Familial Hypocalciuric Hypercalcemia, Primary Hyperparathyroidism, or Both?

Primary hyperparathyroidism (PHPT) is the leading cause of hypercalcemia, and it is characterized by hypercalcemia and normal or inappropriately high levels of parathyroid hormone (PTH). Familial Hypocalciuric hypercalcemia (FHH) is a rare autosomal dominant benign disease caused by inactivating genetic mutations in the calcium sensing receptor. Genetic analyses are expensive and not widely available, making the differential diagnosis challenging. A 77-year-old male with a past medical history of hypertension and chronic kidney disease was referred to the endocrinology clinic for evaluation of hypercalcemia. Routine tests showed total corrected calcium level of 10.5 mg/dL, hypophosphatemia 2.6 mg/dL and low 24h urinary calcium of 79 mg/24h with calcium creatinine clearance ratio (CCCR) of 0.008. 25 hydroxyvitamin D, 1,25 Dihydroxyvitamin D and magnesium were normal. PTH level was 33 pg/dL (normal 15-65 pg/dL). Patient had no hypercalcemic symptoms, history of nephrolithiasis, or bone fractures. No family history of hypercalcemia. Cancer screening and PTH related peptide were normal. He was not taking hydrochlorothiazide or lithium. Renal ultrasound showed no nephrolithiasis and DXA revealed no osteoporosis. Thyroid ultrasound showed a right 1.2cm thyroid nodule without visualization of parathyroid glands. Fine-needle aspiration biopsy (FNA) of the nodule with PTH washout was benign with PTH<10. The patient was diagnosed with FHH and was monitored semiannually. Four years after the initial evaluation, total corrected calcium level was elevated at 14 mg/dL with PTH of 378 despite 25 hydroxyvitamin D level >40, repeated urinary calcium 90 mg/24h, and CCCR 0.01. His renal function was unchanged. Parathyroid scintigraphy revealed increased uptake in the right upper thyroid lobe, and thyroid ultrasound revealed increased right thyroid nodule volume. Repeat FNA was benign, this time with a PTH washout >200. The patient opted against surgical consultation for parathyroidectomy. He was treated with cinacalcet 30 mg twice daily. The co-existence of FHH and PHPT is rare. The few reported cases include patients who maintained hypercalcemia after surgical treatment of PHPT. The best cost-effective test available is a CCCR < 0.02. Our patient had CCCR measured at different times with values < 0.01 and a PTH level that over time increased by 900%. The overlap of biochemical values in patients with FHH and PHPT contributes to the challenges in the differential diagnosis and highlights the importance of close follow up with a high degree of clinical suspicion.

Comparison of Neck Ultrasonography, Dual Phase 99mTc-Sestamibi with early SPECT-CT & 18F-Fluorocholine PET-CT as First Line Imaging in Patients with Primary Hyperparathyroidism.

Successful surgical treatment for primary hyperparathyroidism requires accurate localization of abnormal parathyroid tissue in terms of location and number. Imaging is important for localizing the parathyroid adenoma, and there has been significant interest in 18F-fluorocholine (FCH) positron emission tomography/computed tomography (PET/CT) for this purpose. This study attempted to ascertain the utility of 18F-FCH PET/CT as a first-line investigation in preoperative localization of abnormal parathyroid tissue in primary hyperparathyroidism, in comparison with 99mTc-sestamibi dual-phase scintigraphy with early single-photon emission computed tomography (SPECT)/CT and neck ultrasonography. Fifty-five patients with biochemical features of primary hyperparathyroidism were enrolled in this study. They underwent neck ultrasonography, 99mTc-sestamibi dual-phase scintigraphy with early SPECT/CT, and 18F-FCH PET/CT for localization of parathyroid lesions. Thirty-three patients underwent surgical resection of the detected lesions. For two patients, clinical and biochemical follow-up was used as a gold standard. A total of 40 lesions were resected in the 33 patients who underwent surgery. A further two lesions were localized in two patients with clinical and biochemical follow-up as the gold standard. Of these 42 lesions, 41 were detected in preoperative imaging and 1 lesion was noted intraoperatively and resected. 41/42 lesions were detected by 18F-FCH PET/CT (detection rate: 97.6%), 33/42 by 99mTc-sestamibi dual-phase scintigraphy with early SPECT/CT (detection rate: 78.5%), and 30/42 by neck ultrasonography (detection rate: 71.4%). Detection rates on 18F-FCH PET/CT were superior to both 99mTc-sestamibi dual-phase scintigraphy with early SPECT/CT and neck ultrasonography in preoperative localization of parathyroid lesions in patients with primary hyperparathyroidism.

Surgery for primary hyperparathyroidism.

Primary hyperparathyroidism (PHPT) is a hypercalcemic disorder that occurs when one or more parathyroid glands produces excessive parathyroid hormone (PTH). PHPT is typically treated with surgery, and it remains the only definitive therapy, whose techniques have evolved over previous decades. Advances in preoperative localization exams and the intraoperative PTH monitoring have become the cornerstones of recent parathyroidectomy techniques, as minimally invasive techniques are appropriate for most patients. Nevertheless, these techniques, are not suitable for PHPT patients who are at risk for multiglandular disease, especially in those who present with familial forms of PHPT that require bilateral neck exploration. This manuscript also explores other conditions that warrant special consideration during surgical treatment for PHPT: normocalcemic primary hyperparathyroidism, pregnancy, reoperation for persistent or recurrent PHPT, parathyroid carcinoma, and familial and genetic forms of hyperparathyroidism.

Parathormone concentration in the fluid of fine-needle parathyroid biopsy for assessing the effectiveness of surgical treatment of patients with primary hyperparathyroidism.

The aim of the work was to evaluate the usefulness of intraoperative determination of parathyroid hormone (PTH) concentration in the fluid of fine-needle biopsy lesions of pathologically parathyroid glands for their identification and evaluation of the effectiveness of surgical treatment of primary hyperparathyroidism (PHP). The study group comprised 75 patients: 65 women and 10 men, aged 33-78 years (mean 57.5), operated in the years 2019-2020 due to PHP. Seventy-nine biopsies of fine-needle aspiration lesions were assessed intraoperatively as pathological parathyroid glands were collected, and the concentration of PTH was determined in their lavage fluid. The results were compared with a control group of 20 patients operated at that time for various forms of goitre, without concomitant parathyroid disease. In 79 biopsies, the presence of the parathyroid gland was confirmed 72 times. The concentration of PTH in the biopsy fluid exceeded the value of 5000 pg/mL 70 times, 1 was 3733 pg/mL, and 1 was 1985 pg/mL. Seven times (8.9%), the biopsy was for a colloidal nodule instead of the parathyroid gland. The concentration of PTH in the fluids of these biopsies was low and ranged from 5.3 to 500 pg/mL. In the control group, the concentration of PTH in postoperative thyroid biopsies was low and did not exceed the reference value range of up to 64 pg/mL. Comparison of the results of the study group with the control group shows significantly higher PTH values in parathyroid biopsies compared to biopsies of thyroid specimens (p = 0.017), with a sensitivity of 100% and a specificity of nearly 93%. Intraoperative determination of PTH concentration in the fluid of fine-needle biopsy lesions with diseased parathyroid glands allows for their identification and evaluation of the effectiveness of surgical treatment of PHP. Testing the concentration of PTH in the biopsy fluid of dissected parathyroid glands is characterized by high sensitivity and specificity of the method. The value of PTH concentration in fluid from parathyroid biopsies does not depend on the cause of PHP.

Role and Recent Trend of Intraoperative Parathyroid Hormone Monitoring During Parathyroidectomy in Patients With Primary Hyperparathyroidism

In the last few decades, the standard surgical treatment for primary hyperparathyroidism (PHPT) has shifted from bilateral neck exploration to focused/minimally invasive parathyroidectomy (FMIP). This shift was accelerated by the introduction of intraoperative parathyroid hormone (IOPTH) monitoring, which can provide intraoperative information regarding the localization and complete excision of the pathological parathyroid gland during FMIP. Since the first clinical application of the IOPTH assay in 1991, IOPTH monitoring has substantially improved to date to increase its performance and availability. In addition, the clinical applications of IOPTH changed with the needs of actual clinical practice, although the fundamental concept and technique remained unchanged. In this review, we discuss the role of IOPTH monitoring in the surgical management of PHPT based on the results of contemporary studies and summarized the major issues regarding IOPTH.

Acromegaly caused by a GHRH-producing pancreatic neuroendocrine tumor: a rare manifestation of MEN1 syndrome.

SummaryMultiple endocrine neoplasia type 1 NM_001370259.2(MEN1):c.466G>C(p.Gly156Arg) is characterized by tumors of various endocrine organs. We report on a rare, growth hormone-releasing hormone (GHRH)-releasing pancreatic tumor in a MEN1 patient with a long-term follow-up after surgery. A 22-year-old male with MEN1 syndrome, primary hyperparathyroidism and an acromegalic habitus was observed to have a pancreatic tumor on abdominal CT scanning, growth hormone (GH) and insulin-like growth factor 1 (IGF1) were elevated and plasma GHRH was exceptionally high. GHRH and GH were measured before the treatment and were followed during the study. During octreotide treatment, IGF1 normalized and the GH curve was near normal. After surgical treatment of primary hyperparathyroidism, a pancreatic tail tumor was enucleated. The tumor cells were positive for GHRH antibody staining. After the operation, acromegaly was cured as judged by laboratory tests. No reactivation of acromegaly has been seen during a 20-year follow-up. In conclusion, an ectopic GHRH-producing, pancreatic endocrine neoplasia may represent a rare manifestation of MEN1 syndrome.Learning pointsClinical suspicion is in a key position in detecting acromegaly.Remember genetic disorders with young individuals having primary hyperparathyroidism.Consider multiple endocrine neoplasia type 1 syndrome when a person has several endocrine neoplasia.Acromegaly may be of ectopic origin with patients showing no abnormalities in radiological imaging of the pituitary gland.

IS CONFIRMATION OF PARATHYROID TISSUE BY FROZEN SECTION SUPERIOR TO LOCALIZATION OF SOLITARY PARATHYROID ADENOMA USING INTRAOPERATIVE GAMMA PROBE SURVEY? A RETROSPECTIVE COHORT STUDY.

In the surgical treatment of primary hyperparathyroidism, intraoperative localization of the diseased glands is an essential issue. We aimed to evaluate the impact of the intraoperative frozen section during radio-guided focused parathyroidectomy and compare its efficiency with intraoperative gamma probe survey and measurement of intraoperative quick parathyroid hormone. All consecutive patients underwent radio-guided focused parathyroidectomy for primary hyperparathyroidism due to solitary parathyroid adenoma. The outcomes of parathyroidectomy were evaluated by serum levels of calcium and parathyroid hormone. The primary outcome was the surgical cure diagnosed by normal serum calcium levels in the sixth postoperative month. A total of 55 patients with a mean age of 54.3±12.2 years were evaluated. The diagnostic accuracy of the preoperative localization tests was calculated as 92.7%. The intraoperative gamma probe survey impacted the operative plans of four patients (7.3%) by localizing the diseased gland in other positions. The accuracy of intraoperative quick parathyroid hormone and frozen section analysis was 100% for both. In all patients, serum calcium and PTH levels dropped to normal in the sixth postoperative month. There were no cases of the persistent or recurrent disease during the follow-up period. The results of the intraoperative gamma probe survey, intraoperative quick parathyroid hormone, and frozen section were concordant with the final pathology in all cases. In four patients (7.3%), intraoperative gamma probe survey impacted the operative plans. The intraoperative gamma probe survey may be used as the sole intraoperative method to locate the correct position of the solitary parathyroid adenoma.

Analysis of the cause and management of persistent laboratory abnormalities occurring after the surgical treatment of primary hyperparathyroidism.

PurposeThe surgical success rate for primary hyperparathyroidism (PHPT) is currently 95%–98%. However, 3%–24% of patients show persistently elevated (Pe) parathyroid hormone (PTH) levels after parathyroidectomy (PTX). This single-center retrospective study aimed to compare the outcomes of patients with normal PTH and PePTH levels after successful PTX and to identify the factors associated with PePTH.MethodsThe normal group, defined as patients with normal serum calcium and PTH levels immediately after PTX, was compared with the PePTH group (patients with normal or low serum calcium and increased serum PTH levels up to 6 months postoperatively) to determine the causes of disease in the PePTH group.ResultsThere were no significant differences in age, sex, or preoperative estimated glomerular filtration rate between the normal PTH group (333 of 364, 91.5%) and the PePTH group (31 of 364, 8.5%). However, there were significant differences in preoperative 25-hydroxyvitamin D (17.9 and 11.8 ng/mL, respectively; P = 0.003) and PTH levels (125.5 and 212.4 pg/mL, respectively; P < 0.001) between the 2 groups. Among the 31 cases of the PePTH group, 18 were attributed to vitamin D deficiency.ConclusionPreoperative vitamin D deficiency is a predictive factor for PePTH. Therefore, preoperative administration of vitamin D supplements may reduce the probability of postoperative disease persistence. Patients with temporary laboratory abnormalities within 6 months after successful PTX should be monitored, and appropriate vitamin D and calcium supplementation may reduce the effort and cost of various examinations or reoperations.

ПРОГНОЗИРОВАНИЕ И ДИАГНОСТИКА МНОЖЕСТВЕННОГО ПОРАЖЕНИЯ ОКОЛОЩИТОВИДНЫХ ЖЕЛЕЗ ПРИ ПЕРВИЧНОМ ГИПЕРПАРАТИРЕОЗЕ МЕТОДОМ МАТЕМАТИЧЕСКОГО АНАЛИЗА

Background. Multigland parathyroid disease remains an unresolved problem in endocrine surgery. This is caused by the complexity of clinical and laboratory prediction, insufficient sensitivity of imaging methods and intraoperative monitoring of intact parathyroid hormone. The aim. To develop a predictive scale for multigland parathyroid disease in primary hyperparathyroidism. Materials and methods. We conducted a single-center prospective study which included 126 cases of surgical treat-ment of primary hyperparathyroidism (2019–2021). The main objective of the study was to develop a scale for predicting multigland parathyroid disease in primary hyperparathyroidism using the method of mathematical analysis. Results. The developed scale includes determination of serum levels of albumin-corrected calcium and parathy-roid hormone, glomerular filtration rate, measurement of parathyroid glands parameters according to ultrasound and/or scintigraphy and assessment of the consistency of these results and determination of the KIB coefficient. The results are appraised by points. If the total score is less than 2 points, multigland parathyroid disease is diagnosed; if the total score equals to or more than 2 points – single-gland parathyroid disease. Conclusion. Mathematical prediction of multigland parathyroid disease allows us to clarify the preoperative diagnosis and to plan the scope of surgical treatment.

R35 Early Experiences of Thoracoscopic Parathyroid Gland Resection in New Zealand

Surgical treatment of primary hyperparathyroidism can be complicated by the presence of ectopic mediastinal parathyroid adenomas, which occurs in up to 25% of cases. The majority of mediastinal parathyroid glands can be removed through a cervical incision. However, when this approach is inadequate for access to deeper glands, traditional approaches such as mediastinoscopy, sternotomy or thoracotomy are required. Historically, extracervical approaches to ectopic glands can be associated with increased surgical risk and complications.

Molecular profile of parathyroid tissues and tumours: a heterogeneous landscape.

Advances in laboratory diagnostics and surgical treatment ofprimary hyperparathyroidism have ensured solid basis for research in parathyroid pathology in order to specify key molecules in pathogenesis and morphological diagnostics ofdifficult cases. Theaim ofthis study was to assess themolecular landscape and its heterogeneity in primary parathyroid hyperplasia (PPH) and adenoma, compared to carcinoma and normal glands. In aretrospective analysis of179 surgically removed parathyroid glands (102 adenomas; 27 PPH; 45 normal glands; 5 carcinomas), expression ofKi-67, p21, p27, p53, cyclin D1, Bcl-2 protein, vimentin, cytokeratin (CK) 19, E-cadherin, CD56, CD44 and parafibromin was detected by immunohistochemistry, followed by computer-assisted assessment ofmean values and heterogeneity measures. Descriptive statistics and Kruskal-Wallis test were applied. Significant differences were disclosed regarding themean and highest fraction ofKi-67 (both p < 0.001), p21 (both p < 0.001), cyclin D1 (p = 0.002) and p27-expressing cells (p = 0.010). Proliferative lesions (PPH, adenoma and carcinoma) showed statistically significantly up-regulated CK19 (p = 0.012), decreased E-cadherin levels and distinctive patterns ofvimentin. CD44, CD56 and p53 were almost absent from parathyroid tissues. All carcinomas lacked parafibromin contrasting with invariable positivity in adenomas. Remarkable heterogeneity ofcell cycle markers and intermediate filaments must be accounted for in scientific studies and elaboration ofdiagnostic cut-offs.

Selective venous sampling in primary hyperparathyroidism: Is it worth doing?

Accurate preoperative localization of the culprit gland is the key point for the surgical treatment of primary hyperparathyroidism. Conventional imaging techniques (ultrasound and Tc99m sestamibi scintigraphy) are usually adequate for preoperative localization. However, in some patient groups, additional imaging modalities may be required since noninvasive techniques may fail. In this study, we aimed to evaluate the diagnostic value of selective parathyroid venous sampling in patients with unclear noninvasive localization tests. Among 513 cases who underwent parathyroidectomy due to primary hyperparathyroidism, twelve cases (2.3%) were undergone selective parathyroid venous sampling and were included in the study. Age, sex, presenting symptom, presence of a genetic disease, medical and surgical history, serum calcium (Ca)-parathormone (PTH) levels (preoperative, intraoperative, and postoperative), imaging reports (US, SM, and SVS), surgery reports, pathology reports, and complications were retrospectively reviewed. Seven cases (58.3%) had persistent primary hyperparathyroidism and one patient (8.3%) had past surgical history of total thyroidectomy. The remaining four patients (33.3%) had no previous neck surgery. T he sensitivity of selective venous sampling was 75%. According to the medical history, accurate localization was achieved in 85.7% of persistent cases and 60% of primary cases. Eight cases (66.6%) underwent unilateral neck exploration and four cases (33.3%) underwent four gland exploration. A single adenoma was detected in ten cases (90.9%) while one patient (9.1%) had double adenoma.

Maternal and foetal outcomes associated with medical and surgical treatment of primary hyperparathyroidism in Pregnancy

Maternal and foetal outcomes associated with medical and surgical treatment of primary hyperparathyroidism in Pregnancy

Surgical treatment in patients with single and multiple gland primary hyperparathyroidism with the use of intraoperative parathyroid hormone monitoring: extensive single-center experience.

To evaluate a single-center extensive experience and effectiveness in surgical treatment of primary hyperparathyroidism (pHPT) with the use of rapid intraoperative parathyroid hormone (ioPTH) monitoring in patients with single gland (SGpH) or multiple gland (MGpH) disease. This retrospective, single-center cohort study included 214 patients with pHPT treated from January 2010 to June 2017. In total, 172 patients fulfilled the inclusion criteria having at least one preoperative localization image study and measurement of ioPTH. Statistical analysis was made by the chi-square test and Student's t tests. Of the 172 patients, 146 were women (85%) and 26 men (15%), with a mean age of 56.9years; 153 (89%) had SGpH and 19 (11%) MGpH. The mean follow-up was 41.8months. A total of 153 surgical procedures were performed as minimal invasive parathyroidectomy (MIP) based on a SGpH diagnosis; operative success was achieved in 150 cases (98%), according to ioPTH concentrations. The remainder (19 procedures) were performed as bilateral neck exploration (BNE) based on a MGpH diagnosis; operative success was achieved in 16 cases (84%). ioPTH correctly modified the initially planned operation in 26.3% of patients with MGpH. ioPTH enables the surgical treatment of patients with pHPT with focused approaches and excellent results, as it helps the surgeon to identify cases of MGpH. ioPTH adds value to cases where preoperative imaging failed to detect the affected gland or the results are inconclusive. According to the literature, its application seems to be of marginal benefit in cases in which there are two concordant preoperative imaging studies.

Transoral Endoscopic Parathyroidectomy Vestibular Approach (TOEPVA)—Choosing the Right Patient

Parathyroidectomy is the surgical treatment for primary hyperparathyroidism. A single parathyroid adenoma is the most common cause of primary hyperparathyroidism (PHPT) making it amenable to a focused surgery whereby the putative hyperfunctional parathyroid gland is excised. Parathyroid surgery, like thyroid surgery, is typically performed through a cervical incision usually measuring 4–5 cm. Though most surgical scars heal well over time, the presence of a scar may affect a patient’s quality of life (Goldfarb and Casillas, Thyroid. 26(7):923–32, 2016; Choi et al., Ann Dermatol. 26(6):693–9, 2014). Surgeons may perceive scars differently and more favorably than patients. Variables such as scar length do not always correlate with patient satisfaction (Arora et al., Int J Surg. 25:38–43, 2016; Toll et al., Eur Arch Otorhinolaryngol. 269(1):309–13, 2012; Linos et al., Surgery 153(3):400–7, 2013). Remote access approach to the parathyroid: Remote access approaches such as transoral and axillo-bilateral-breast approaches have been proposed to access the suspected hyperfunctional parathyroid gland similar to the thyroid to avoid a scar in the neck (He et al., J Laparoendosc Adv Surg Tech. 25(4):311–3, 2015). Transoral endoscopic thyroidectomy vestibular approach (TOETVA) for thyroidectomy introduced by Anuwong is gaining popularity as a remote access approach with feasibility demonstrated by several groups (Dionigi et al., J Endocrinol Invest. 40(11):1259–63, 2017; Russell et al., Thyroid. 28(7):825–829, 2018; Anuwong et al., Surg Endosc. 32(1):456–65, 2018). Focused parathyroid surgery may also be completed via this approach (TOEPVA) (Sasanakietkul et al., Surg Endosc. 31(9):3755–63, 2017).

Persistently Elevated PTH After Parathyroidectomy at One Year: Experience in a Tertiary Referral Center.

Increased PTH after successful parathyroid surgery represents a clinical conundrum. We aimed to determine the prevalence of persistently elevated PTH (PePTH) postsurgery, along with predisposing factors. and Setting: Patients ≥ age 18 with parathyroidectomy performed at University of North Carolina Hospitals for primary hyperparathyroidism (PHPT) over a 12-year period were identified from the Carolina Data Warehouse. Clinical and demographic characteristics were collected, transformed, and analyzed. Five hundred seventy patients met initial criteria for PHPT, and of those 407 had postoperative values. One hundred forty-four had laboratory results within 3 to 18 months post operatively. There was no clinical difference between those with and without long-term laboratory follow-up. Presurgery, patients had average calcium of 11 mg/dL and PTH 125.4 pg/mL. Ninety-seven percent of patients had normalized calcium after surgery, but 30% had PePTH, which can be predicted at 3 months. Patients with PePTH (persistent elevation of PTH) after surgery did not differ from those with normalized PTH in terms of sex, age, body mass index, or excised gland weight; presurgery 25-vitamin D was slightly lower, but not abnormal (26 ± 15 vs 36 ± 11). The presurgical PTH was significantly higher (P < 0.001) in those with PePTH (156.5 pg/mL compared with presurgical level of 102.5 in those whose PTH normalized). Nearly one-third of PHPT patients have elevated PTH levels postsurgery in a tertiary hospital setting. At presentation, patients with PePTH tend to have higher PTH relative to calcium levels. Whether PePTH after surgical treatment of PHPT has pathological consequences is unknown.

SAT-504 Role of Genetic Screening for FHH in a Patient with Hypercalcemia and Hyperparathyroidism

Background The estimated prevalence of primary hyperparathyroidism (PHPT) is one per 1000 whereas familial hypocalciuric hypercalcemia (FHH) is one per 78,000. Distinguishing between PHPT and FHH can be challenging due to the similarity in biochemical picture. PTH can be normal in 48% of patients with PHPT and 80% of patients with FHH. PHPT patients are generally older and has a history of normal serum calcium with a new onset hypercalcemia. Endocrine society guideline suggests using 24h-CCCR (calcium-to-creatinine clearance ratio) to differentiate with 24h-CCCR <1% as an indicator for FHH and >2% as an indicator for PHPT. Case A 28 years-old African American lady with bipolar disorder is noted to have asymptomatic hypercalcemia in the range of 11.1 to 12.2 mg/dl (ref: 8.4-10.3) by routine lab since 2012 with PTH level of 14 to 155 pg/ml (ref: 12-88). She has never been treated with Lithium. Vitamin D was 25-32 ng/ml (ref: 30-100). Phosphorous was 2-2.4 mg/dl (ref: 2.4-4.5). Magnesium was normal. She has no history of fracture nor renal stone. She has no family history of hypercalcemia. She had a decline in creatine clearance from 96 ml/min to 67 ml/min over a year. 24h-CCCR was < 1% and remained low even after calcium supplementation. No parathyroid adenoma was localized on imaging. Plasma metanephrine was normal. Due to 24h-CCCR <1%, a genetic panel for FHH was performed. She has FHH1 with heterozygous mutation at CASR (c.1972C>T). Discussion FHH is an autosomal-dominant disease with a loss of function mutation at CASR (FHH1), GNA11 (FHH2) or AP2S1 (FHH3). FHH1 is the most common and constitutes 65-90% of FHH. It has a high degree of penetrance. Loss-of-function mutation in CASR causes reduced sensitivity of calcium sensing in parathyroid chief cells resulting in PTH secretion, increased reabsorption of calcium in renal tubule and increased serum calcium. Family history of hypercalcemia and 24h-CCCR <1% suggest FHH. However, the urinary calcium excretion in patients with PHPT and FHH can also be overlapped. In the study reported by Bertocchio et al, 2% of FHH had 24h-CCCR values over 2% and 26% PHPT patients had 24h-CCCR <1%. Concomitant vitamin D deficiency and very low dietary calcium intake may lower 24h-CCCR. In addition, a patient may have coexisting FHH and PHPT or FHH and MEN. Genetic screening for FHH may not feasible or cost-effective in every case of hypercalcemia and hyperparathyroidism with 24h-CCCR <1%. Untreated PHPT increases the risk of renal stones, renal failure, osteoporosis and fracture. Surgical treatment of primary hyperparathyroidism is curative. However, differentiating PHPT from FHH is paramount to avoid unnecessary surgery in a patient with FHH. Clinical Lesson The biochemical picture of PHPT and FHH can be overlapped including 24h-CCCR value. Hence, genetic screening for FHH should be considered routinely in a patient with 24h-CCCR < 1% before considering a parathyroid surgery.