bluuebunny/crossref_metadata_2025 huggingface dataset:
FRI684 So Strong Yet So Fragile: Bilateral Periprosthetic Fractures On Denosumab
Authors: Syeda Asma , Mirza Faryal Sardar
Published: October 2023

Disclosure: A. Syeda: None. F.S. Mirza: None.

Background: Denosumab (DN) is a potent antiresorptive and has been associated rarely with atypical femoral fractures. We hereby report the first case of simultaneous bilateral femoral periprosthetic fractures (PPF) while on DN therapy (DNT). Clinical Case: A 78-year-old female with severe osteoporosis on DNT presented in January 2023 with bilateral femoral PPF after a mechanical fall whereby she tripped and landed on her knees. The patient had initially presented to us in late 2012. Treatment history included alendronate (ALN) for 5 years, on drug holiday since 2010. She underwent bilateral knee replacement surgeries in 2012 and DNT was started in 2013 after initial evaluation. She also had primary biliary cirrhosis, and although bone density (BD) improved on DNT, she exhibited escape from DN mediated suppression of bone resorption possibly related to the liver disease that was previously reported (1). DNT was stopped 5 years later when spine BD improved to osteopenic range and ALN 70 mg weekly was started. 1 year later, bone resorption markers were still elevated and zoledronic acid was substituted for ALN. She fell and had a pubic ramus fracture 11 months later. BD showed a 6% decrease for mean total hip and baseline forearm BD showed T-score of -3.7 on the right. DNT was restarted in December 2020 and continued every 6 months. Her health continued to deteriorate over next two years, with increase in LFTS, new anemia and thrombocytopenia due to a combination of myelodysplastic syndrome and splenomegaly. She also needed transcatheter aortic valve replacement for worsening CHF. She tripped and fell in January 2023. X-ray showed acute supracondylar bilateral PPF with comminution. She was high risk for anesthesia and anticoagulation was withheld due to a history of thrombocytopenia and gastrointestinal bleeding. Prior to the anticipated orthopaedic procedure, the patient developed severe hypotension and a rapid drop in hematocrit due to hemorrhagic shock. The family had requested DNR due to the multitude of medical issues. Conclusion: Occasional PPF have been reported in the setting of DNT, which may reflect the severity of osteoporosis. Altered stress distribution and decreased tensile strength of the bone secondary to screw/pin placement are thought to contribute to PPF, although the occurrence of PPF as an unusual presentation of an AFF cannot be excluded. Contribution of other comorbidities to poor bone quality may also have contributed to the bilateral PPF with poor outcome in our patient.

1. Vedere, T.R. and Mirza, F.S., 2017, April. Escape from Denosumab Mediated Suppression of Bone Resorption in Primary Biliary Cirrhosis. In 99th Annual Meeting of the Endocrine Society. Endocrine Society.

Presentation: Friday, June 16, 2023
FRI687 Clinical Relevance Of 24-hour Urine Calcium Measurement In Patients With Primary Hyperparathyroidism (PHPT)
Authors: Bhan Arti , Simon Rebecca , Jacobsen Gordon , Yaseen Aseel , Navaratnarajah Preyantha , Sweidan Aroob , Rao Sudhaker D
Published: October 2023

Disclosure: A. Bhan: None. R. Simon: None. G. Jacobsen: None. A. Yaseen: None. P. Navaratnarajah: None. A. Sweidan: None. S.D. Rao: None.

Introduction: PHPT is the third most common endocrine disease and the most common cause of hypercalcemia in outpatient setting, presents with mild to moderate hypercalcemia with unsuppressed or elevated serum PTH levels, and most patients are asymptomatic. A 24-hour urine Ca measurement to exclude both hypo- and hypercalciuria is used to recommend parathyroidectomy. The purpose of our study is to evaluate the clinical relevance of urine Ca measurement in evaluating patients with PHPT. Methods: A retrospective electronic medical record review was performed on all adult patients with PHPT in whom a 24-hour urine Ca was measured between 2015-2019. Patients with secondary HPT, those without a 24-hour urine Ca measurement, and patients with serum Cr >1.5 mg/dl were excluded. Results: 393 patients met inclusion criteria for subsequent analyses. For the entire cohort, mean serum Ca was 10.9 ± 0.6 mg/dl, Cr 0.9 ± 0.2 mg/dl and PTH 111± 65 pg/ml with no significant difference between groups by gender, race, or stone history. Mean urine Ca for the entire cohort was 254 ± 170 mg/day. 46% and 35% had urine Ca >250 or >300 mg/d respectively. Multiple linear regression results indicated that higher serum Ca (p=0.004), lower serum Cr (p<0.001), white race (p<0.001), and higher urine sodium (p<0.001) were all significantly predictive of higher UCa. However, the mean urine Ca did not differ between patients with and without nephrolithiasis (276 ± 182 Vs. 280 ± 247 mg/d; p=0.174). Discussion: The most recent guidelines for the management of asymptomatic PHPT recommend measurement of 24-hour urine Ca in all PHPT patients. However, the validity, sensitivity and specificity of such an approach has never been formally evaluated, considering wide variability of urine Ca excretion in the population and lack of difference in urine Ca between patients with and without nephrolithiasis. Previous guidelines discussed this issue and determined that measurement of a 24-hour urine collection is cumbersome and adds very little to patient management. Our study questions the clinical relevance of re-including 24-hour urine Ca in the latest guidelines. Conclusions: Our study suggests that measurement of 24-hour urine Ca in the routine evaluation of patients with PHPT is unhelpful.

Presentation: Friday, June 16, 2023
FRI693 Pthrp Mediated Hypercalcemia In A Patient With Recurrent Hepatocellular Carcinoma
Authors: Bondarenko Darya , Ahmad Mobeen , Mack Margaret , Ucciferro Peter
Published: October 2023

Disclosure: D. Bondarenko: None. M. Ahmad: None. M. Mack: None. P. Ucciferro: None.

Background: Humoral hypercalcemia is seen in 30 percent of cancer patients, most commonly driven by parathyroid hormone related peptide (PTHrP) production, osteolytic cytokine production, and 1,25-OH vitamin D production. The most common malignancies associated with PTHrP mediated hypercalcemia are squamous cell carcinomas and breast cancer. Less often hepatocellular cancer presents with hypercalcemia. We describe the case of a patient presenting with hepatocellular carcinoma presenting with recurrent episodes of severe hypercalcemia due to excessive PTHrP production. Clinical Case: The patient was a 68-year-old male with a past medical history of recurrent hepatocellular carcinoma with liver transplant in the past and type 2 diabetes mellitus who presented to the emergency department (ED) for one day of altered mental status. The patient was noted to be extremely agitated and confused by his home health aide and EMS was called. In the ED the patient’s vital signs were as follows: blood pressure of 196/80 mmHg, heart rate of 82 beats per minute, respiratory rate of 18 breaths per minute and temperature of 36.6 degrees Celsius. Initial lab work showed: calcium 13.5 mg/dL, albumin 4.2 g/dL, ionized calcium of 1.63 mmol/L, creatinine 0.99 mg/dL (baseline 0.5 mg/dL), glucose of 438 mg/dL, bicarbonate 23 mmol/L, anion gap 19, and beta hydroxybutyrate 51 mg/dL. Hypercalcemia workup revealed a suppressed PTH of 5 pg/mL (normal 11-67 pg), normal 25-OH vitamin D 43.6 ng/ml (normal 30-100 ng/ml), normal 1,25-OH vitamin D 38 pg/ml (normal 18-72 pg/ml), and elevated PTHrp 36 pg/ml (normal 11-20 pg/ml). The patient was started on aggressive IV fluid resuscitation with normal saline, administered a one-time dose of zoledronic acid and administered a three-day course of calcitonin. For his significant hyperglycemia the patient was started on an insulin infusion and was eventually transitioned to his home basal bolus insulin regimen. On discharge, the patient was scheduled with his oncologist to begin denosumab as an outpatient; however, he chose a palliative approach due to the terminal nature of his disease and recurrent hospitalizations for hypercalcemia. Conclusion: Hypercalcemia of malignancy is common in many different carcinomas with squamous cell cancer, renal cell cancer, breast cancer and multiple myeloma being commonly associated with this phenomenon. Reports of hepatocellular carcinoma associated with hypercalcemia are less common and occur in only 4-8 % of cases. With this case report, we hope to highlight PTHrP as a potential mechanism of humoral hypercalcemia in patients with hepatocellular carcinoma and propose denosumab as a possible treatment for patients with refractory hypercalcemia of malignancy.

Presentation: Friday, June 16, 2023
FRI697 Severe Hypocalcemia Due To Idiopathic Hypoparathyroidism In An Elderly Female
Authors: Chopra Karishma A.
Published: October 2023

Disclosure: K.A. Chopra: None.

Most cases of acquired hypoparathyroidism in adulthood occur after neck surgery or radiation. However, idiopathic cases, although rare, do occur in elderly patients and should be a diagnosis of exclusion after thorough investigation. 76-year-old female with a history of chronic kidney disease, anemia of chronic disease, and hypertension presented with fatigue. Labs showed calcium (Ca) 5.7(RR 8.4-10.2 mg/dL), albumin 3.5(RR 3.5-5 g/dL), magnesium 2(RR 1.6-2.5 mg/dL), phosphorus 7.8(RR 2.5-4.4 mg/dL), parathyroid hormone 9(RR 15-75 pg/mL), 25-hydroxyvitamin D 32(RR 12-99 ng/mL). Patient denied history of neck surgery or radiation. Patient denied nephrolithiasis, perioral numbness, paresthesias, family history of hypoparathyroidism. Physical exam notable for positive Chvostek sign. Neck ultrasound unremarkable, no evidence of infiltrative disease. Urine Ca was low at 6 mg/24 hour(RR 100-300 mg/24hr). ACE level 10 nmol/ml/min(RR<40 nmol/ml/min) and 1,25 dihydroxyvitamin D level 12(RR 18-78 pg/mL) making sarcoidosis or granulomatous disease unlikely. HIV screen negative and interferon gamma response to mycobacterium tuberculosis antigens was not detected. Ferritin elevated at 300(RR 12-150 ng/mL) but transferrin saturation was 15%(RR 15-55%), not consistent with hemochromatosis. Antiparathyroid antibodies were negative. Patient denied mucocutaneous candidiasis, however testing for underlying autoimmune polyglandular syndrome type 1 (APS type 1) and adrenal insufficiency was completed with cosyntropin stimulation test. Patient had normal response to cosyntropin with baseline cortisol 20.1 (RR 6-18.4 ug/dL) and ACTH 37.7(RR<52 pg/mL), 30 minute cortisol 27(RR 6-18.4 ug/dL) and 60 minute cortisol 37(RR 6-18.4 ug/dL). Patient was treated with Ca gluconate infusion (100 ml of 10% Ca gluconate in 1000 mL of normal saline) at 30 ml/hr and Ca level gradually improved. Once Ca level was greater than 8.0(RR 8.4-10.2 mg/dL), Ca drip was discontinued. Due to patient’s lack of prior neck surgery history, lack of evidence of infiltrative conditions, negative antiparathyroid antibodies, normal adrenal function (unlikely APS type 1), lack of family history, and low urine Ca (unlikely activating mutation of Ca sensing receptor), patient’s hypoparathyroidism was considered idiopathic. Patient was discharged on oral Ca carbonate, Ca acetate, and calcitriol tablets. On follow up, patient had Ca 8.5(RR 8.4-10.2 mg/dL) with symptom improvement. Although hypocalcemia is commonly encountered, it is rare to see severe hypocalcemia in an elderly patient due to hypoparathyroidism without a history of neck surgery or radiation. Therefore, it is vitally important to conduct a thorough investigation to rule out underlying causes before diagnosing idiopathic hypoparathyroidism as highlighted in our case to guide future treatment and optimize patient health.

Presentation: Friday, June 16, 2023
FRI698 Hypoparathyroidism Secondary To Covid-19
Authors: Hussain Mariam , Reddy Tina K , Mohiuddin Arianna , Lovre Dragana , Galagan Robert
Published: October 2023

Disclosure: M. Hussain: None. T.K. Reddy: None. A. Mohiuddin: None. D. Lovre: None. R. Galagan: None.

Introduction: New onset adult hypoparathyroidism is most often caused by thyroid surgery or autoimmune illness. To date, little is known about the effect of the novel coronavirus (SARS-CoV-2) on parathyroid glands. Most recent hypotheses are that Covid-19 might affect the parathyroid glands directly through invasion of parathyroid gland tissues by SARS-CoV-2 virus or indirectly secondary to respiratory failure and chronic respiratory alkalosis.

Case Report: We report the case of a 32-year-old male with post-viral hypoparathyroidism secondary to COVID-19.Only a few cases of COVID-19 induced hypoparathyroidism have been reported in the literature. Our patient was admitted to the hospital for severe and symptomatic hypocalcemia three weeks after a viral-like upper respiratory tract infection and diarrhea. He complained of paresthesias, muscle cramps and muscle weakness. He had no autoimmune or neck surgical history. Initial lab test results revealed a corrected calcium of 4.5 mg/dL (8.4-10.3 mg/dL), ionized calcium 2.4 mg/dL (4.5-5.3 mg/dL), PTH < 1.0 pg/mL (12-65 pg/mL), phosphorus 6.2 mg/dL (2.5-4.7 mg/dL), magnesium 1.6 mg/dL (1.5-2.6 mg/dL), Vit D, 25-hydroxy 17.3 ng/mL (30-100 ng/mL), and creatinine 1.13 mg/dL (0.7-1.4 mg/dL), consistent with hypoparathyroidism. An ECG showed QTc prolongation to 506 msec. SARS-coV-2/flu/RSV cepheid multiplex was negative, SARS-CoV-2 Spike Ab was positive. He had never received a COVID vaccine. The patient was admitted to ICU for IV calcium drip, oral calcium and calcitriol supplementation. He was transitioned to a medical ward when his severe hypocalcemia was corrected and he was ultimately discharged on oral calcitriol 1 mcg BID and calcium carbonate 1000 mg po TID. A thorough workup for a cause of the hypoparathyroidism was performed, including anti-PTH antibody, 21-hydroxylase antibody, TSI, and TPO antibody, all of which were negative. Genetic testing was performed, including CASR gene sequencing analysis and AIRE DNA sequencing, both of which were negative. After other causes of hypoparathyroidism were excluded, COVID-19 was reasoned to be the etiology of this patient’s hypoparathyroidism. Our case highlights a post-viral hypoparathyroidism secondary to COVID-19. Further studies are needed to elucidate the mechanistic relationship between COVID-19 and hypoparathyroidism.

Presentation: Friday, June 16, 2023
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

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

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
SAT196 COVID-19 Pneumonia And Primary Hyperparathyroidism Exacerbation
Authors: Khan Anum , Rimal Priya , Biggs Megan , Ahmed Ammar , Musurakis Clio , Gilden Janice L , Moid Alvia
Published: October 2023

Disclosure: A. Khan: None. P. Rimal: None. M. Biggs: None. A. Ahmed: None. C. Musurakis: None. J.L. Gilden: None. A. Moid: None.

Introduction: It is well known that COVID-19 virus damages the body by either inflicting the injury directly, or by initiating a systemic immune response, resulting in inflammation. Our case report explores how parathyroid glandular dysfunction and calcium levels (Ca) can be affected in a patient with active COVID-19 pneumonia. Clinical Case: A 58-year-old male, unvaccinated for COVID-19, with COPD, primary hyperparathyroidism (PHPT), chronic kidney disease, and ethanol use presented to the emergency room with confusion, vomiting, and lethargy. Preadmission medications included hydrochlorothiazide. Following a positive COVID-19 test, he was diagnosed with acute hypoxic respiratory failure secondary to COVID-19 pneumonia. After emergent treatment with BiPAP and IV steroids, he was transferred to the ICU, where he completed treatment with remdesivir, dexamethasone, and baricitinib. He was also treated for ethanol withdrawal. Notably, this patient had a history of chronic asymptomatic hypercalcemia secondary to PHPT with Ca prior to admission ranging from 10.9-13.6 mg/dl (nl=8.5-10.1mg/dl), PTH range 145-345 pg/ml (nl=14-65 pg/ml), creatinine (Cr) 1.2-1.4 mg/dl (nl= 0.67-1.17 mg/dl). On this admission, Ca was 12.2mg/dl, albumin 2.4 g/dl (3.4-5.0 g/dl), PTH 531 pg/ml, Cr 3.4 mg/dl, 25OH vitamin D 29.3 ng/mL (nl= 30-100 ng/mL). After fluids, Ca initially improved to 10.9mg/dl and Cr soon after normalized. Mental status also improved after hydration. However, Ca then rose significantly to 14.1mg/dl with mental status decline. IV zoledronic acid was administered, resulting in lowering serum calcium and improvement of mental status. Conclusion: This patient’s clinical course was notable for the improvement of Ca initially with hydration. However, a significant rise in Ca approaching parathyroid crisis range was seen shortly thereafter, despite normalization of Cr. Whereas hypocalcemia has been noted in most cases of Ca dysfunction associated with COVID-19 infection, in this case, we postulate that the COVID-19 infection may have triggered parathyroiditis, thus exacerbating the underlying PHPT. One such mechanism is the use of receptors like angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) by COVID-19 virus, which are found on endocrine glands including the parathyroid. Similarly, COVID-19 virus exerts its inflammatory effects using IL-6, which is also a key cytokine that causes hypercalcemia by stimulating bone resorption. Furthermore, COVID-19 infection is notorious for causing nausea/vomiting, and diarrhea, culminating in dehydration which worsens hypercalcemia. It is therefore necessary that physicians foresee impending complications of COVID-19 infection with concurrent parathyroid disease and take early steps to prevent and treat them.

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

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

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

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

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

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

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
SAT239 Deceased Donor Parathyroid Allotransplant For Sever Refractory Iatrogenic Hypoparathyroidism
Authors: Devon Karen M , Zahedi Afshan , Madani Amin , Pasternak Jesse D , Saravana-Bawan Bianka , Humar Atul , Kathryn Tinckam
Published: October 2023

Disclosure: K.M. Devon: None. A. Zahedi: None. A. Madani: None. J.D. Pasternak: None. B. Saravana-Bawan: None. A. Humar: None. T. Kathryn: None.

While Halstead experimented with dog parathyroid transplantation, the first reported human parathyroid allotransplant appeared in the Annals of Surgery in 1911. Efforts of varying success in restoring calcium homeostasis in patients with refractory hypoparathyroidism after thyroidectomy have included parathyroid transplantation(tx), mainly in immunosuppressed kidney transplant recipients, using cryopreserved, cultured, or hypercellular tissues. Recently, cases of living-donor parathyroid allotransplants have been reported. We present a 46 year-old woman who developed hypoparathyroidism following total thyroidectomy 9 years prior. Treatment included two years of continuous teriparatide via CAD pump. Complications of portacath sepsis and pulmonary emboli, required intensive care. At the time of transplantation, our patient was taking elemental calcium 16 grams daily, magnesium 12 grams daily, calcitriol 8 ug daily, hydroochlorothiazide 25 mg twice daily, and nonetheless requiring biweekly intravenous calcium for symptoms and Calcium levels of 1.6 mmol/l (2.2-2.6 mmol/L). PTH ranged between 0.6- 1.2 pmol/l with poor quality of life. A medically suitable neurologically deceased donor was identified through the provincial organ donation organization. Her cumulative cPRA was 98% (Class I-95%/II-81%). Virtual crossmatch only positive for DQ2 specificity with weak positive B-cell flow crossmatch. Four healthy parathyroids were retrieved. The tissue was minced and placed into pockets in the recipient’s right brachioradialis muscle, under local anaesthesia with sedation. Ischemic time was 2.5 hours. She was induced with basiliximab and received tacrolimus, mycophenolate, and prednisone as immunotherapy. Evidence of biochemical parathyroid function was present post-tx day 9, and she was weaned off all calcium homeostatic medications by day 35, remaining asymptomatic at 7 months at the time of writing, with no calcium infusions. Self-reported quality of life is significantly improved. PTH 0.8-2.8 pmol/L and Calcium 2.06-2.37 mmol/l. To our knowledge this is the first successful fresh normal tissue deceased donor parathyroid transplant in a non-transplant recipient in North America. One study suggests that despite immunosuppression risks, 14 percent of patients would entertain parathyroid allotransplantation. We are currently recruiting additional patients with the aim of demonstrating that deceased donor parathyroid allotransplant using fresh tissue and immunosuppression is a novel viable and curative approach to treat permanent severe hypoparathyroidism.

Presentation: Saturday, June 17, 2023
SAT241 Severe Hypercalcemia Secondary To Likely Sarcoidosis
Authors: Nair Nirmal
Published: October 2023

Disclosure: N. Nair: None.

A 42 year old gentleman with no known past medical history initially presented to the Endocrinology office referred from his primary care provider for the evaluation of severe hypercalcemia. He initially presented to his PCP with 8 months of progressive tachycardia, shortness of breath and persistently elevated blood pressures but was noted with a serum calcium of 14.9. On my initial evaluation, patient was well appearing, tachycardic with normal rate and rhythm with otherwise no abnormal findings. His blood pressure was elevated to 150s systolic from a baseline of less than 120. Based on the severity of the initial hypercalcemia, an extensive workup was sent to rule out potential etiologies for his hypercalcemia including Vitamin D, PTH, PTHrp, serum free and light chains, CMP, ionized calcium, and serum protein electrophoresis. The initial workup revealed a calcium improved to 12.1 from the initial 14.9, with significant elevation in ionized calcium. PTH and 25 hydroxyvitamin D were suppressed, ruling out primary hyperparathyroidism. Interestingly, 1,25 dihyroxyvitamin D levels were within the upper limit of normal, raising the possibility of granulomatous disease. PTHrp was elevated. Serum protein electrophoresis had revealed mild elevations in beta immunoglobulins. Based on the findings of the initial workup, concern remained for granulomatous disease and malignancy, and a CT of the chest, abdomen and pelvis was ordered. CT showed bilateral perihilar interstitial nodules, mildly enlarged mediastinal and hilar lymph nodes, and splenomegaly with ill defined splenic lesions. No mass or tumor was identified in this study. Although the potential for monoclonal gammopathies and malignancy remain in the differential diagnosis, his presentation, CT scan, and lab findings may be explained by sarcoidosis. While the normal 1,25 Vitamin D levels in the setting of suppressed PTH and 25 Vitamin D may be more classically associated with granulomatous disease, significant renal impairment, elevations in PTHrp and immunoglobulins are not uncommon, making sarcoidosis a likely explanation for his symptoms short of obtaining a biopsy. He was subsequently referred to pulmonology to evaluate for sarcoidosis and to oncology to evaluate further the elevations in serum immunoglobulins. This patient presentation is unique as it is not common to encounter cases of severe hypercalcemia in the outpatient setting. Here, it is important to note that PTHrp elevations and elevations in light chains may be seen in sarcoidosis as well as malignancy. This case illustrates the importance of a wide differential diagnosis in order to avoid the pitfall of prematurely determining a working diagnosis.

Presentation: Saturday, June 17, 2023