bluuebunny/crossref_metadata_2025_split huggingface dataset:
SAT178 EZH2 Upregulation And Lysine 27 Trimethylation at Histone 3 Is Associated With Severe Sporadic Primary Hyperparathyroidism
Authors: Kumari Poonam , Kumar Arya Ashutosh , Dahiya Divya , Sachdeva Naresh , Kaur Jyotdeep , Nahar Saikia Uma , Bhadada Sanjay , Rao Sudhaker D 
Published: October 2023

Abstract
Disclosure: P. Kumari: None. A.K. Arya: None. D. Dahiya: None. N. Sachdeva: None. J. Kaur: None. U.N. Saikia: None. S. Bhadada: None. S.D. Rao: None.
Introduction: The enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase that regulates gene activity through histone modifications of lysine (K) at H3 histone and has a crucial role in tumor development. However, the level of methylation at H3 histone and its association with EZH2 expression in sporadic primary hyperparathyroidism (PHPT) are not known. This study was designed to investigate how global levels of histone methylation were associated with altered expression of EZH2 in promoting parathyroid tumorigenesis. Methodology: A total of 30 parathyroid tumors (15 non-severe, 15 severe, and 5 normal parathyroid tissues) were collected during 2020-2021. The global histone methylation of major methylation sites at lysine (K) K4, K9, K27, K36, and K79 was evaluated from blood and tissue samples using a calorimetric ELISA (H3 global modification kit, Epegentek, USA). Gene and protein expression of EZH2 were performed by quantitative real-time PCR and immunohistochemistry respectively. Histone methylation and expression data were correlated with indices of disease severity. Results: We found that the global levels of H3K27me1 and me3 were significantly upregulated, whereas, H3K4me3 and H3K36me2 were significantly downregulated in tumors from patients with severe PHPT compared to tumors from non-severe PHPT and controls. Moreover, H3K27me3 showed the highest upregulation (8-fold) in severe PHPT. Additionally, EZH2 gene expression was significantly upregulated in severe PHPT [Mean ± S.E; (9.1 ± 1.6 vs. 1.2 ± 0.3, p = 0.005), but not in non-severe (4.2 ± 2.7 vs. 1.2 ± 0.3, p = 0.4) PHPT, compared to normal parathyroid tissues. Furthermore, the protein expression was also consistent with the gene expression, with 86% (n= 13/15) nuclear positivity for EZH2 in tumors from severe PHPT and 40% (6 of 15) in tumors from non-severe PHPT compared to normal parathyroid tissue (negative staining). Correlation analysis revealed that EZH2 gene expression is positively related with S.Ca (r = 0.44, p = 0.003), PTH (r = 0.59, p = 0.000), tumor weight (r = 0.455, p = 0.002), EZH2 protein expression (r = 0.7, p = 0.000), and Ki67 proliferative marker (r = 0.66, p = 0.002). Conclusions: Increased global trimethylation of K27 at histone 3 (H3K27me3) was associated with increased EZH2 expression in sporadic PHPT and was predictive of a more severe clinical phenotype. Sources of research support: (ICMR), New Delhi Extramural Research Grant 2020.
Presentation: Saturday, June 17, 2023
SAT183 What Determines Bone Mineral Density Changes After Successful Parathyroidectomy In Primary Hyperparathyroidism?
Authors: Esteban Mosquera Jorge , Li Xilong , Maalouf Naim 
Published: October 2023

Abstract
Disclosure: J.E. Mosquera: None. X. Li: None. N. Maalouf: None.
Background: Parathyroidectomy (PTX) is the only cure for primary hyperparathyroidism (PHPT). However, the impact of PTX on bone mineral density (BMD) is very variable. Methods: To assess the impact of demographic and clinical characteristics on BMD change post-PTX, we retrospectively reviewed charts of patients with biochemically proven PHPT and successful PTX between 2006 and 2022 at our institution and who had available pre- and post-PTX DXA scans. We extracted available demographic, clinical, and laboratory data including age, gender, race, body mass index, pre-PTX serum parathyroid hormone, calcium, phosphorus, alkaline phosphatase (Alkphos), 25-OH-vitamin D, and creatinine, 24-hour urine calcium, and use of bisphosphonates. The association between these parameters and BMD changes were assessed using univariate and multivariate models. Results: 121 patients (107 women) were included in this analysis. 35% were African American and 50% Hispanic. At PTX, mean (SD) age was 59 (12) years, BMI was 33 (7) kg/m2. 36% had osteopenia and 47% had osteoporosis on pre-PTX DXA. 6% of patients used BP before PTX and 3% used BP within one year of PTX. At year 1 post-PTX, median BMD (25th-75th percentile) change was +2.7% (-0.2% - +6.6%) at the lumbar spine (LS), +2.4% (-0.5% - +5.9%) at the femoral neck (FN), +2.8% (0.7% - +4.7%) at total hip (TH), and +0.1% (-3.6% - +3.0%) at the 1/3 radius. In univariate analyses, 1-year change in FN BMD was positively associated with highest pre-PTX serum calcium, PTH, and Alkphos, and negatively associated with age and serum creatinine. TH BMD change at 1 year was positively associated with highest pre-PTX PTH and Alkphos, and negatively associated with lowest T-score at baseline, age, and pre-PTX serum phosphorus, 25-OH-D and creatinine. LS BMD change at 1 year was positively associated with highest pre-PTX serum calcium and PTH, and negatively associated with lowest phosphorus pre-PTX. In multivariate analyses, younger age, highest pre-PTX serum calcium, and lowest BMD T-score pre-PTX were all independently and significantly associated with greater increase in post-PTX BMD at the FN, TH, and LS. Moreover, pre-PTX Alkphos was associated with greater BMD gain at the FN and TH, while female gender was associated with greater gain in LS BMD. Conclusions: In patients with PHPT who undergo curative PTX, variable BMD changes are observed at 1-year post-PTX. Younger age at PTX, higher serum calcium, and lower BMD pre-PTX are all associated with greater BMD gains post-PTX. These findings should be considered in the counseling of PHPT patients undergoing PTX.
Presentation: Saturday, June 17, 2023
SAT197 A Rare Case Of Infected Parathyroid Cyst Associated With Hyperparathyroidism
Authors: Ataallah Basma , Al Tameemi Mohammed , Orlander Philip R 
Published: October 2023

Abstract
Disclosure: B. Ataallah: None. M. Al Tameemi: None. P.R. Orlander: None.
Introduction: Parathyroid cysts are considered rare lesions compromising 1-5 % of neck masses. Clinical pictures can range from asymptomatic to symptoms and signs of hyperparathyroidism, and it may lead to compressive symptoms as well. Infection of the parathyroid cyst is not reported in literature. We are presenting a patient with parathyroid cyst and was found to be infected with E-coli. Case presentation: A 59-year-old woman presented with neck swelling and ear pain. She was initially diagnosed with otitis externa and was treated with antibiotics. Her neck swelling worsens over a brief period with associated ear drainage and shortness of breath. Computed tomography (CT) scan of the neck revealed a large cystic lesion up to 10 cm in largest diameter in the region of the thyroid gland with inflammatory changes extending to the prevertebral soft tissues. CT scan of the chest showed a mass effect on the trachea and adjacent structures with possible hemorrhage. Eventually the patient was intubated. Laboratory evaluation revealed parathyroid hormone (PTH) at 455 pg/ml, corrected calcium of 11.3 mg/dl, Ionized calcium of 1.41 mMol/L, and phosphorus at 3.0 mg/dl. Aspiration of the cyst was done prior to surgery and the culture grew E-coli. She started on antibiotics, and eventually underwent a total thyroidectomy with excision of the parathyroid cyst and adenoma. Pathology showed a ruptured cyst with marked inflammation and granulation tissue with hypercellular left superior parathyroid gland. Postoperatively, corrected calcium dropped to 10.1mg/dl and PTH to 38.5 pg/ml. Discussion: Parathyroid cyst (PC) is a relatively rare neck or mediastinal lesion, representing less than 0.5% of parathyroid gland disorders. Most PCs are nonfunctional, but some may produce excess parathyroid hormone or can cause local compressive symptoms like dyspnea, dysphagia, or hoarseness of voice, depending on the size and location of the lesion. There are no distinct clinical or radiological features to differentiate parathyroid cysts, and that makes preoperative diagnosis challenging, and most cases are diagnosed during surgery or postoperatively. Aspiration and fluid analysis can confirm the diagnosis preoperatively, and the treatment can be achieved either by cyst aspiration for small lesions with less than 2.5 cm in diameter, through sclerosing agent injection, or by surgical resection. In this patient, the culture of the aspirated parathyroid cyst surprisingly grew E coli. It is unusual to have an infection with E coli in the neck tissues or the surrounding structures, and it is unknown whether the cyst infection is related to the ear infection that our patient has. Parathyroid cyst infection is not reported in literature reviews, and it is important to consider fluid analysis and culture to confirm the diagnosis preoperatively and to rule out cyst infection
Presentation: Saturday, June 17, 2023
SAT200 A Case Of Ectopic Parathyroid Adenoma With Significantly Improved Renal Function And Insulin Resistance After Parathyroidectomy
Authors: Lee Sihoon , Ppyun Hyewoo , Shin Yoochan , Hong Namki , Seok Choi Han 
Published: October 2023

Abstract
Disclosure: S. Lee: None. H. Ppyun: None. Y. Shin: None. N. Hong: None. H. Choi: None.
Background: It is challenging to treat patients with clinically suspected hyperparathyroidism not localized by conventional imaging methods. Here, we present clinical evidence that supports new modalities for localization and ultimate surgical removal of a lesion. Clinical case: An increase in calcium and PTH was found incidentally in a 59 YO male patient who was followed up for type 2 diabetes mellitus and DMCKD (stage 4). Initial lab tests were as follows: Ca, 11.6 mg/dL (8.2∼10.8); P 3.3 mg/dL (2.5∼4.7); PTH 184.1 pg/mL (18.5∼88.0); BUN/Cr 4.84/3.38 mg/dL (8∼22/0.5∼1.2); protein in random urine 1020.1 mg/dL (6∼20). Suspected of primary hyperparathyroidism, ultrasonography and sestamibi scan were performed, but no parathyroid lesions were found. While only palliative treatment was maintained, parathyroid venous sampling (PVS) (1) and 18-fluorocholine PET/CT (2) were performed, and a mass within 2 cm in diameter was found in the left mediastinum, which was then removed by thoracoscopic robotic excision. Diffuse weak staining for PTH in the removed lesion confirmed that it was a tissue derived from the parathyroid gland. After surgery, lab tests were improved as follows: Ca 9.1 mg/dL; P 3.6 mg/dL; PTH 69 pg/mL. When 90 units of insulin were administered before surgery, HbA1c was 8.7%, but even after insulin was reduced to 15 units post-surgery HbA1c decreased to 7.2%, significantly reducing the need for insulin treatment. Proteinuria also decreased to 123.1 mg/dL, indicating that renal function was also improved. Conclusion: This case highlights the merit of newly introduced 18-fluorocholine PET/CT and PVS to find a parathyroid lesion that could not be found by conventional imaging methods. It is recommended to consider active surgical treatment for hyperparathyroidism, mainly to prevent deterioration of bone health and kidney function. In addition, since concurrent diabetes can be improved by parathyroidectomy (3), this case shows the need to more actively find lesions and take a causal approach. Reference: (1) Yamada T, Ikuno M, Shinjo Y, Hiroishi A, Matsushita S, Morimoto T, et al. Selective venous sampling for primary hyperparathyroidism: how to perform an examination and interpret the results with reference to thyroid vein anatomy. Jpn. J. Radiol. 2017;35:409-16. (2) Marina Orevi 1, Nanette Freedman, Eyal Mishani, Moshe Bocher, Orit Jacobson, Yodphat Krausz. Localization of parathyroid adenoma by ¹¹C-choline PET/CT: preliminary results. Clin. Nucl. Med. 2014;39:1033-8 (3) Noghani SN, Milani N, Afkhamizadeh M, Kabiri M, Bonakdaran S, Vazifeh-Mostaan L, et al. Assessment of insulin resistance in patients with primary hyperparathyroidism before and after Parathyroidectomy. Endocrinol Diab Metab. 2021;4:e00294.
Presentation: Saturday, June 17, 2023
SAT204 Parafibromin: Key To The Diagnosis Of Atypical Parathyroid Adenoma In A Patient With Suspected Carcinoma
Authors: Anunobi Vanessa , Fernandez-Lopez Kristel , Clement Cecilia , Shah Nisarg , Belalcazar L Maria 
Published: October 2023

Abstract
Disclosure: V. Anunobi: None. K. Fernandez-Lopez: None. C. Clement: None. N. Shah: None. L. Belalcazar: None.
Introduction: Parathyroid carcinoma (PTCa), although a rare endocrine malignancy, should be considered in the differential diagnosis of severe parathyroid (PTH)-mediated hypercalcemia. We present the case of a patient in whom clinical presentation suggested a PTCa, but histological analysis with the use of a parafibromin (PF) stain helped identify the patient’s parathyroid mass as an atypical parathyroid adenoma (APTa). PF stain is now in the World Health Organization (WHO) guidelines for the differentiation of PTCa and APTa. Case Presentation: A 71-year-old woman was admitted to the hospital for an incidental finding of hypercalcemia and complaints of fatigue, myalgias, constipation and generalized weakness. On exam, the patient was alert and oriented; she had a palpable right neck nodule. Laboratory testing included serum calcium of 13.9 mg/dL (8.6-10.6mg/dL) and phosphorus of 2.4 mg/dL (2.5-5.0 mg/dL). PTH level was 3,547.4 pg/mL (12-88 pg/mL) and eGFR was 67ml/min/1.73m2. Patient had undergone a neck ultrasound prior to admission that described a 2.6 cm right thyroid nodule, however fine needle aspiration revealed that the nodule was a parathyroid mass. Further imaging, including a sestamibi nuclear scan and a neck tomography, confirmed the presence of a large right inferior parathyroid adenoma. After correction of hypercalcemia, the patient underwent a right parathyroidectomy and right hemithyroidectomy. Pathology identified a 7.7 g mass, 3 cm. on its greatest diameter. There was no evidence of lymphovascular or perineural invasion, or extension into the parathyroid capsule or thyroid gland. The mass was strongly positive for PF staining in more than 50 % of tumor cells and was categorized as an APTa. Discussion: Differentiating APTa from PTca is challenging. Preserved PF tumor expression in parathyroid tumors makes PTca unlikely and is linked with a low risk of tumor recurrence. Endocrinologists need to be aware of the utility of the PF stain when evaluating patients suspected to have a PTca. The WHO now recommends that a PF stain be included in the pathological evaluation of these tumors.
Presentation: Saturday, June 17, 2023
SAT213 Post-parathyroidectomy Acute Pseudogout Flare-up; A Case Report
Authors: Rabiei Samaneh , Kantorovich Vitaly 
Published: October 2023

Abstract
Disclosure: S. Rabiei: None. V. Kantorovich: None.
Introduction: Acute post-parathyroidectomy pseudogout has been reported in the early post-operative. Although the exact mechanism is unknown, accepted theories include decreased solubility of calcium pyrophosphate and unbalanced equilibrium between production and hydrolysis of inorganic phosphate. We present a patient who developed an acute pseudogout attack after parathyroidectomy. The Case: Patient is a 45-year-old male with a history of nephrolithiasis who presented to outpatient clinic with a right-sided neck mass that has been present for several years with recent increase in size. He reported unintentional weight loss (25 pounds) and night sweats. On physical examination, a right lateral neck mass measuring 6 x 4 cm was noted. CT scan of the neck demonstrated a complex mass with calcification. Serum calcium (Ca), phosphorus (P), potassium (K), and alkaline phosphatase levels were 17.2 mg/dL, 1.8 mg/dL, 2.6 mmol/L, and 1,782 U/L, respectively. Serum intact parathyroid hormone (iPTH) was 3,341 pg/mL. The patient was then admitted. He received intravenous fluid, zolindronic acid, and started on vitamin D supplementation in preparation for surgery. Pre-operative CT scan of the chest, abdomen, and pelvis was concerning for metastatic disease (retroperitoneal lymphadenopathy, multiple bilateral lung solid nodules, liver, kidney and bone lesions). The patient underwent complete resection of the tumor. Intra-operative frozen section confirmed parathyroid tumor with atypia. Twenty-minute post-excision iPTH was 476 pg/mL. In the early post-operative period, serum Ca level was reduced to 7.5-8.5 mg/dL and oral Ca and calcitriol supplementation were administered. However, serum PTH reached levels as high as 900 pg/mL. Post-operative MRI demonstrated benign liver and kidney lesion with non-visualization of the previously reported retroperitoneal lymph nodes and pulmonary nodules on the CT.A few days later, the patient complained of bilateral knee pain. Serum Ca, P, and PTH levels were 7.9 mg/dL, 3.0 mg/dL, and 861 pg/mL, respectively. The skeletal survey revealed diffuse osseous metabolic process with scattered lucent osseous lesions compatible with osteitis fibrosa cystica/brown tumors as well as chondrocalcinosis of knees and hand joints. Prednisone was started for treatment of presumed acute CPPD attack with subsequent significant resolution of patient’s joint pain. Discussion: This case demonstrated the importance of thorough evaluation of musculoskeletal complaints in patients with hyperparathyroidism. Bone and joint pain in patients with hyperparathyroidism is common and is most often the result of high bone turnover. However, other etiologies including acute pseudogout should be contemplated in order to provide the appropriate treatment. Post-parathyroidectomy acute pseudogout attack should generally be treated in the same way as in the general population.
Presentation: Saturday, June 17, 2023
SAT223 Persistent Hypocalcemia After Thyroidectomy
Authors: Subramani Rashmi , Manas F N U , Kauser Asnia , Yavuz Sahzene 
Published: October 2023

Abstract
Disclosure: R. Subramani: None. F. Manas: None. A. Kauser: None. S. Yavuz: None.
Introduction: Hypocalcemia is one of the serious complications after total thyroidectomy with a reported incidence of 27.4% (transient)and 12.1% (permanent) probably related to iatrogenic parathyroidectomy. Here we report a case of hypocalcemia after thyroidectomy in the setting of normal parathyroid hormone levels. Summary: A 42-year-old female with medical history of multinodular goiter s/p thyroidectomy 2019 on thyroid hormone replacement presented with hypocalcemia since 2021. During the first-year post thyroidectomy, patient was doing well until she acquired COVID-19 in 2020 and started developing symptoms of paresthesia, and muscle spasms. Other parameters such as phosphorus, and 25 OH vitamin D were normal. Despite being on a high-dose calcium supplement 1200 mg every hour for 10 times daily and calcitriol 0.75 mg twice daily, her calcium levels were persistently low ranging between 7.1 to 8 mg/dl and normal albumin levels of 3.9 and 4.3, but parathyroid level (PTH) remained normal (27.7-37.5). The patient was also symptomatic. She was later switched to liquid calcium 1000 mg 6 times daily for better absorption. It is noted that she had recurrent symptomatic hypocalcemia episodes requiring multiple emergency room (ER) visits during times of stress such as viral illness. The patient was treated with a trial of teriparatide, after which her symptoms improved and there were no further ER visits. Her calcium level increased from 7.4 to 8.4 and calcium supplement requirement reduced to 1200 mg daily. During recent outpatient visit, the patient had hypocalcemia episodes after missing teriparatide doses as expected. Conclusion: Despite our patient had normal PTH levels, the parathyroids glands did not respond appropriately to hypocalcemia. Promberger et al studied a case of eight patients with hypocalcemia with normal PTH following thyroidectomy. All these patients had normal PTH levels during post-op period, but persistently low and ionized calcium levels 12 months after surgery. This suggests during persistent hypocalcemia normal parathyroid levels may indicate an inadequate PTH response. In our case, developing hypocalcemia long after surgery and relation to COVID-19 infection may suggest autoimmune phenomenon as developing PTH-antibodies or receptor malfunction, theory yet to be investigated. In cases of severe symptomatic hypocalcemia requiring significant amount of calcium supplement PTH analogs are very effective treatment.
Presentation: Saturday, June 17, 2023
SAT224 Nonsurgical Hypoparathyroidism: 40 Years After Diagnosis
Authors: Ilyse Kaplan Leah , Yuen Alexa , Dale Greenberg Pietra 
Published: October 2023

Abstract
Disclosure: L.I. Kaplan: None. A. Yuen: None. P.D. Greenberg: None.
Background: The majority of cases of hypoparathyroidism occur after neck surgery. The most common nonsurgical cause is autoimmune, either in isolation or part of Autoimmune Polyglandular Syndrome Type 1. Hypomagnesemia is a functional cause. Hypoparathyroidism can occur as part of genetic syndromes that include congenital anomalies, short stature and developmental delay. Non-syndromic genetic etiologies including Autosomal Dominant Hypocalcemia type 1 (ADH1), a gain of function mutation in the calcium sensing receptor (CaSR) that can present in infancy, childhood or adulthood with hypocalcemia (50% symptomatic), hypercalcuria (10%) and basal ganglia calcification (35%). For ADH1, targeted therapies are being developed. Clinical Case: A 90-year-old male was diagnosed with hypoparathyroidism at age 50 when he presented with hand cramping and was found to have hypocalcemia with low PTH. He was started on calcitriol and calcium supplementation. Many years later he started following at our endocrine clinic. Past medical history includes prostate cancer treated with radiation and androgen deprivation therapy, HTN, and pre-diabetes. He has no history of neck surgery, other endocrinopathies, candidiasis, vitiligo or congenital anomalies. He has no family history of hypocalcemia and has two children without calcium abnormalities. His DEXA shows stable +T scores in LS spine and bilateral hips. He has not had brain imaging. Nephrocalcinosis was not reported on renal ultrasound. More than 10 years ago, he presented with severe hypercalcemia, acute renal failure (Ca 13.5 mg/dl, Cr 6.0mg/dl, Phos 5.5mg/dl) and ureteral stones after taking over the counter calcium supplements in excess. He underwent stone removal with return to baseline renal function. Subsequently, he underwent knee replacement surgeries and required IV calcium until he was able to swallow pills. Since this time, he has been managed on calcitriol, calcium carbonate, vitamin D3, and chlorthalidone with close follow up for adjustment of regimen to target Ca 8.0-8.5 mg/dl. He has not had a recurrence of severe hypercalcemia, hyperphosphatemia or nephrolithiasis. He feels well and lives at home with his wife. Lab values over the past 10 years are as follows: Ca 8.1-10.6 mg/dl (8.5-10.5), Alb 4.0-4.6 g/dl (3.5-5.4), Phos 4.3-5.5 mg/dl (2.8-4.5), Mg 1.7-1.9 mg/dl (1.3-2.1), K 3.7-4.4 mEq/L (3.6-5.2), Cr 1.0-1.5 mg/dl (0.5-1.3), PTH 0.00-1.4 pg/ml (10-55), 25 OH Vit D 18-58 ng/ml (32-100), 1,25 OH Vit D3 25.5-37.2 pg/ml (19.9-79.3), 24hr Urine Ca 162- 384 mg/24 hrs (50-400). Clinical lessons: Chronic hypoparathyroidism can be well managed with close follow up and frequent lab monitoring. This patient should be referred for genetic testing, particularly to look for ADH1 mutation in the CaSR gene as targeted treatments are being developed. His children should be tested for any mutations found in him.
Presentation: Saturday, June 17, 2023