Intraoperative Parathyroid Hormone Levels Research Articles

1053 Parathyroid Phenomenon Causing Primary Hyperparathyroidism: A Case for Surgeons, Radiologists and Pathologists

Abstract Background Parathyroid lipoadenomas are a rare parathyroid phenomenon and an unusual cause of primary hyperparathyroidism. The histological composition of these neoplasms makes them a diagnostic challenge, as their high adipose content leads to difficulty localising them on imaging and can lead pathologists towards a wrong diagnosis. There are less than 100 cases in the literature since they were first described in 1958, and to our knowledge this is the largest parathyroid lipoadenoma to be reported. Method A minimally invasive parathyroidectomy with intraoperative parathyroid hormone monitoring was performed in the case of a male with a large neck mass and symptomatic primary hyperparathyroidism. Results A giant parathyroid lipoadenoma was excised, with an appropriate decrease in intraoperative parathyroid hormone level observed. The patient has been cured of his primary hyperparathyroidism, with no issues following his discharge from our institution. Conclusions We highlight the importance of having the parathyroid lipoadenoma as a differential diagnosis for patients who develop primary hyperparathyroidism.

Evaluation of Focused Mini-Incision Parathyroidectomy in Primary Hyperparathyroidism

Abstract Background In the era of effective preoperative localization and availability of intraoperative parathyroid hormone (IOPTH) assay, the trend now in parathyroidectomy is shifting from bilateral neck exploration (BNE) into minimal invasive parathyroidectomy (MIP). The concept of MIP is based on the fact that 85% of cases have single adenoma. This study highlights the outcomes of focused mini- incision parathyroidectomy (FMIP) for the treatment of selected cases of primary hyperparathyroidism. Aim of study: To evaluate and assess the outcome and advantages of focused mini-incision parathyroidectomy in parathyroid adenoma of primary hyperparathyroidism. Patients and Methods This cohort study was conducted at endocrine surgery unit, Ain Shams University Hospital, and Sohag Cancer Institute including 22 patients with benign solitary parathyroid adenoma; 17 retrospective cases & 5 prospective cases. These included patients had been operated with focused mini-incision parathyroidectomy within the time period from January 2018 to December 2020 as retrospective cases and from January 2021 to December 2021 as prospective cases. Results In this study, age ranged from 30 to 70 years with mean age 50.23 ± 10.71 years. The preoperative serum calcium level ranged from 10.8 to 14.2 mg/dl (mean 12.28 ± 1.16 mg/dl). The preoperative parathyroid hormone level was elevated ranging from 256 to 2090 pg/mL (mean 970.68 ± 563.97 pg/mL). In this study, the operative time ranged from 55 to 75 minutes with mean 64.36 ± 6.33 minutes, percentage of IOPTH decrease level ranged from 75-95 % with mean percentage 85.72 ± 6.28 %. There were no cases with intraoperative bleeding or recurrent laryngeal nerve (RLN) injury. Hospital stay ranged from 6-16 days with mean 10.77 ± 3.10 days. There is no wound infection in all cases. All cases reached a success rate up to 100% (decrease the IOPTH level ≥ 75 %, and resolution of preoperative hypercalcemic manifestations). Conclusion Depending to the high successful rate, very low intraoperative morbidity and better postoperative recovery and cosmoses of FMIP technique, it should be the first choice for pHPT cases with solitary parathyroid adenoma, provided by the concordance localization study of U/S and MIBI scan preoperative.

Clinical protocol using calcium and calcitriol after paediatric total thyroidectomy decreases postoperative hypocalcaemia and inpatient blood tests.

Clinical protocol using calcium and calcitriol after paediatric total thyroidectomy decreases postoperative hypocalcaemia and inpatient blood tests.

The Importance of Level of Drop of Intra-operative Parathyroid Hormone in Predicting Recurrence After Parathyroidectomy for Primary Hyperparathyroidism

Background: During parathyroidectomy for hyperparathyroidism, intraoperative parathyroid hormone (IOPTH) levels are used to confirm excision of parathyroid adenoma. A drop in IOPTH level of 50% or drop to a normal level is associated with a high cure rate. However, there are still a number of patients who fit this criterion who have recurrent hyperparathyroidism. The authors hypothesize that a drop in PTH to a level below 4 pmol/l (37.72 pg/mL) rather than just a 50% drop would decrease the rate of recurrence disease. Methods: The authors conducted a retrospective review of consecutive patients who underwent surgery for parathyroid adenoma between March 2015 and December 2018. Parathyroidectomy was performed with curative parathyroidectomy defined as drop in IOPTH below 4 pmol/l (37.72 pg/mL) after 10-15minutes from excision (2-3 half-life periods of PTH) of abnormal Parathyroid gland. Results: 72 patients were identified who underwent Parathyroidectomy for primary hyperparathyroidism during the study period. Post resection IOPTH levels below 4 pmol/l correctly predicted an operative success rate near 100% in the cohort. Contrarily IOPTH level drop more than 50% but above a level of 4 pmol/l (9 cases) was associated with an additional unidentified Parathyroid adenoma in 7 cases. Conclusions: Post parathyroidectomy drop in IOPTH level below 4 pmol/l appears to be more predictive of successful treatment for primary hyperparathyroidism related to parathyroid adenoma compared to standard criteria.

An individual approach to intraoperative parathyroid hormone measurement during total thyroidectomy

PurposeHypocalcemia is a common complication of thyroidectomy. Measurement of the intraoperative serum parathyroid hormone (PTH) levels became an established technique but it requires further improvements. We aimed to assess intraoperative PTH level testing results against the hypothesis that the PTH assay may be performed almost immediately after thyroid gland removal. MethodsA retrospective cohort study. During total thyroidectomy surgery, the patients had PTH levels measured at the cutting time and again immediately after the thyroid gland is removed. Post-operatively, serial total blood calcium levels were obtained twice daily and recorded. ResultsAmong 63 enrolled patients, 39 had multinodular goiter, 15 thyroid carcinoma, and nine had Graves' disease. The mean age was 59.8 ± 15.3 years, 43 females. The mean PTH level before surgery was 45.8 ± 22.0 pg/mL. Post-operatively, 11/63 patients developed hypocalcemia with serum calcium levels <8 mg/dL. Four patients with ≥50 % decrease in PTH concentration were normocalcemic a day after surgery and were discharged early. Four patients with ≥70 % PTH decrease were treated accordingly during prolonged hospitalization and did not suffer from permanent hypocalcemia. The cut-off value of 70 % decrease after the gland removal was able to predict postoperative hypocalcemia with a sensitivity of 100 %, specificity 82.9 %, PPV 60.0 % and NPV 100 %. ConclusionMeasurements of intraoperative PTH may not be performed at fixed time intervals but after 1–2 min after removal of the thyroid gland. Defining those not at risk would allow the majority of patients to be waived from post-operative blood calcium testing and safely discharged early after surgery.

A >50% Intraoperative Parathyroid Hormone Level Decrease Into Normal Reference Range Predicts Complete Excision of Malignancy in Patients With Parathyroid Carcinoma

IntroductionThe mainstay of successful treatment for parathyroid carcinoma remains complete surgical excision. Although intraoperative parathyroid hormone (ioPTH) monitoring is a useful adjunct during parathyroidectomy for benign primary hyperparathyroidism, its utility for parathyroid carcinoma remains unclear. MethodsA retrospective review of 796 patients who underwent parathyroidectomy with ioPTH monitoring for primary hyperparathyroidism revealed 13 patients with parathyroid carcinoma on final pathology from two academic institutions. A systematic review yielded 5 additional parathyroid carcinoma patients. Complete excision of malignancy, or operative success (eucalcemia ≥6 mo. after parathyroidectomy); operative failure (persistent hypercalcemia <6 mo. after parathyroidectomy); and perioperative complications were evaluated. Comparison of the >50% ioPTH decrease alone to >50% ioPTH decrease into normal reference range was analyzed using Chi-squared, Kolmogorov–Smirnov, Kruskal–Wallis tests. ResultsAll 18 parathyroid carcinoma patients achieved a >50% ioPTH decrease, and 14 patients also had a final ioPTH level decrease into normal reference range. 93% of patients who met normal parathyroid hormone reference range had operative success, whereas only two of the four (50%) patients with parathyroid carcinoma with a >50% ioPTH decrease alone demonstrated operative success. ConclusionsParathyroidectomy guided by a >50% ioPTH decrease into normal reference range may better predict complete excision of malignant tissue in patients with parathyroid carcinoma compared to >50% ioPTH decrease alone. IoPTH monitoring should be used in conjunction with clinical judgment and complete en bloc resection for optimal treatment and success.

Outcomes of subtotal parathyroidectomy for renal hyperparathyroidism

BackgroundRenal hyperparathyroidism due to end-stage kidney disease is associated with considerable morbidity, and when refractory is treated with parathyroidectomy. Recurrent renal hyperparathyroidism is a major surgical complication, yet initial target parathyroid remnant size and outcomes, including rates of recurrence are not well elucidated. MethodsThis is a single-institution retrospective cohort study of patients who underwent initial subtotal parathyroidectomy for renal hyperparathyroidism on dialysis, from 1990–2022. The subtotal parathyroidectomy was defined as resection of 3 parathyroid glands ± partial resection of the fourth gland leaving a remnant of ∼75–100 mg, and postresection intraoperative parathyroid hormone goal was 150–250 pg/mL. Clinical data were examined for outcomes. ResultsAmong 204 patients who met inclusion criteria, 139 (68%) had follow-up data; 58% (80/139) were women and median age was 45 years. Surgical complications included 2 hematomas (1.4%), 1 recurrent laryngeal nerve injury (<1%), and no patient required readmission for intravenous calcium. Using a target remnant size of 75–100 mg, recurrent renal hyperparathyroidism was uncommon (14/139, 10%) and arose at a median interval of 58.6 months (range, 8–180). In cases of recurrence, the postresection intraoperative parathyroid hormone level was less likely to drop <250 pg/mL (40%, 4/10 vs nonrecurrence 65%, 80/123; P = .11) with a slightly lower median decrease (70% vs 81% in nonrecurrence, P = .8); however, neither were significant. Recurrence did not occur in the 19 patients who later received kidney transplantation (P = .2). ConclusionIn subtotal parathyroidectomy for renal hyperparathyroidism, use of a target 75–100 mg remnant size results in low complication rates. Durable cure appears to be more likely with renal transplantation.

SAT249 Femur Lysis Calcium Crisis

Abstract Disclosure: G. Gupta: None. S. Idriss: None. N. Barua: None. J. Hodge: None. I. Jamal: None. Introduction: Primary hyperparathyroidism usually presents with symptoms of bone pain, fatigue, polyuria, constipation, and nephrolithiasis. Here we describe a 27-year-old female with a femoral neck fracture and found to have a parathyroid mass. Case: 27 y/o female with autism spectrum, presented to the ED for evaluation of a mechanical fall and was found to have a left femur and pubic ramus fracture. On arrival she was vitally stable, labs were significant for parathyroid hormone-related hypercalcemia corrected Ca 14.8 mg/dL, PTH 911 peaked to 2884 pg/mL, vit D level of 12.7 ng/mL, phosphorus of 2.3 mg/dL. Trauma workup revealed numerous osseous lytic lesions lower extremities. Review of system was negative except for localized pain at fracture site. Family history negative for hypercalcemia or hyperparathyroidism. She was managed with IV fluids, IV Zoledronic Acid 4 mg, SC calcitonin 240 units, and 50K IU D3. During hospitalization, she needed re-dozing with Zoledronic acid and Cinacalcet due to recurrence of significant hypercalcemia, warranting further imaging. CT neck showed mandibular and maxillary bone lesions raising suspicion of hyperparathyroidism jaw tumor syndrome (HPT-JT) vs brown tumors, 3.1 cm lobular mass inferior to the right thyroid lobe suspicious for large parathyroid adenoma vs carcinoma, and other multiple enlarged parathyroids. She underwent left femur cephalomedullary nailing and prophylactic nailing for the impending right femur fracture. Bone pathology showed fragmented bone, adipose, and skeletal muscle with fibrinous debris. She underwent subtotal parathyroidectomy (4-1/2 glands) and intraoperative PTH level declined from 1537 to 75 pg/mL 15 minutes after removal. Pathology showed tissue consistent with multi glandular parathyroid disease without evidence of malignancy. Postop her course was complicated with hungry bone syndrome requiring a few weeks on IV calcium. Discussion: Pathologic conditions in primary hyperparathyroidism include single adenomas (80-90% of the time), multiglandular hyperplasia multiple-gland (three or more glands) accounting for approximately 6%, and parathyroid carcinomas account for 1-2% of cases. Other conditions as with primary hyperparathyroidism include Familial hyperparathyroidism such as MEN 1 &amp; 2A, Familial isolated hyperparathyroidism, and Familial HPT-JT syndrome, previously termed familial cystic parathyroid adenomatosis. Interestingly our pt had multiglandular hyperplasia which is a less common cause, she also demonstrated jaw lesions but didn’t fulfill the criteria for HPT-JT. Conclusion: Our patient had an unusual presentation of large bone fracture and multiple lytic lesions likely representing a brown tumor of the bone due to primary hyperparathyroidism. Most patients with lytic lesions have malignancy, however, endocrine pathologies should also be considered. Presentation: Saturday, June 17, 2023

Intraoperative Parathyroid Hormone Monitoring In Normohormonal Primary Hyperparathyroidism: How Low Do You Go?

The primary goal of this study was to determine in patients with normohormonal primary hyperparathyroidism (NHHPT) what percent reduction in post-excision intraoperative parathyroid hormone (IOPTH) from baseline would yield a rate of cure comparable to that in patients with classical primary hyperparathyroidism (PHPT). This is a retrospective cohort study of patients who underwent parathyroidectomy between July 2013 and February 2020. Demographic data, preoperative, intraoperative, and postoperative metrics were collected. Patients with NHHPT were compared to those with classical PHPT. Subgroup analyses were performed. Of the 496 patients included in the study, 66 (13.3%) were of the normohormonal variant based on preoperative intact parathyroid hormone (PTH) levels and 28 (5.6%) based on baseline IOPTH levels. The cure rates in the two normohormonal groups were not significantly different from their classical counterparts (98.4% and 100.0% vs. 97.1%, p = 1.000). The median percent decline in post-excision IOPTH from baseline that achieved cure in the normohormonal groups were 82.6% and 80.4% compared to their respective controls at 87.3%, p = 0.011 and p = 0.001. Although the rate of multiglandular disease was higher in one of the normohormonal variant groups, this difference was due to a higher rate of double adenomas, not four-gland hyperplasia. Patients with NHHPT undergoing parathyroidectomy can expect cure rates similar to that in patients with classical PHPT. The results of this study indicate that achieving an 80% drop or more in IOPTH levels predicts a high likelihood of cure. This is true irrespective of whether the patient is deemed normohormonal based on preoperative or intraoperative testing. 3 Laryngoscope, 134:2480-2484, 2024.

Variational Quantum Circuit Topology Grid Search for Hypocalcemia Following Thyroid Surgery

Quantum computing’s potential to revolutionise medical applications has spurred interest in leveraging quantum algorithms for healthcare challenges. In this research, the authors explored the application of variational quantum circuits to predicting hypocalcemia risk following thyroid surgery. Hypocalcemia, resulting from hypoparathyroidism, is a common post-surgical complication. This novel approach includes a topology grid search of the variational quantum circuits. To execute the grid search, our research employed a classical optimiser that guided the adjustment of different circuit topologies, assessing their impact on predictive performance. Our research used, as relevant features, an intra-operative PTH (parathyroid hormone) at 10 min post-removal and percentage decrease of pre-operative and intra-operative PTH levels. The findings revealed insights into the interplay between variational quantum circuit topologies and predictive accuracy for hypocalcemia risk assessment.

Abstract #1406603: An Atypical Clinical Presentation of a Parathyroid Adenoma

Parathyroid adenomas usually appear as well-defined, homogeneous, hypoechoic masses on ultrasound (US). However, atypical features on US including heterogeneity, cystic changes, and calcifications raise suspicion of malignancy. We present a patient with a suspicious atypical clinical presentation of a parathyroid adenoma. A 29-year-old female presented after a fall with a new right nondisplaced proximal tibial pathologic fracture through a large lytic bone lesion. Prior to bone biopsy and operative fixation of the fracture, lab work was significant for a calcium level of 14.8 mg/dL, albumin 4 g/dL, intact parathyroid hormone (PTH) 1,176 pg/mL, 25-hydroxy vitamin D 14 ng/mL, magnesium 1.6 mg/dL, alkaline phosphatase level 483 U/L and phosphorus 2.2 mg/dL. She denied any personal or family history of hypercalcemia, nephrolithiasis, osteoporosis, excessive calcium or vitamin D intake, malignancy or symptoms of abdominal pain, nausea, vomiting, constipation, or dysuria. Of note, the patient had a prior biopsy of the left lytic hip bone lesion eight months prior. Pathology initially revealed a benign process concerning for hemangioma of the bone or fibrous dysplasia; however, retrospective review was consistent with osteitis fibrosa cystica. A thyroid US revealed a heterogeneous 3.9 x 2.4 x 3.0 cm complex solid and cystic mass in the neck posterior to the thyroid between the trachea and carotid, concerning for a malignant neoplasm. Parathyroid scan revealed an intense nodular focus of radiotracer uptake at the inferior pole of the right thyroid lobe suspicious for parathyroid neoplasm. She required intravenous (IV) normal saline, calcitonin, and IV pamidronate due to persistent hypercalcemia. She underwent a right hemithyroidectomy and inferior parathyroidectomy with a closed treatment of her tibial fracture. A pre-excision intraoperative PTH level was 1,473 with a post-excision PTH level of 114. Pathology revealed a cystic parathyroid adenoma. Hungry bone syndrome was prevented postoperatively with calcium carbonate 1 g three times daily, calcitriol 0.5 mg twice daily, and vitamin D3 50,000 IU weekly. This atypical presentation of a parathyroid adenoma is significant because it highlights similarities it can share with parathyroid carcinomas. Initial imaging was highly suspicious for features of malignancy, but surgical pathology was consistent with a parathyroid adenoma. Furthermore, this case is unique because the pathologic finding of osteitis cystica is unusual in the early biochemical diagnosis of hyperparathyroidism. Therefore, clinicians should be aware of this form of disease and include it in their differential in a patient with multiple bone cysts.

Intraoperative Parathyroid Hormone Monitoring Is of Limited Usefulness in Guiding Autotransplantation in Reoperative or Subtotal Parathyroidectomy for Primary Hyperparathyroidism.

Patients with primary hyperparathyroidism (1HPT) undergoing reoperative or subtotal parathyroidectomy (PTX) may undergo autotransplantation (ATX) when the viability of remaining tissue is unknown. This study aims to identify whether intraoperative parathyroid hormone levels (IOPTH) can determine ATX candidacy. Patients with 1HPT who underwent PTX with ATX at our institution were identified. IOPTH and PTH values within 24h, 2-4weeks, and >1month postoperative were analyzed. Patients were classified as either a candidate for ATX (low PTH after 2-4weeks) or not a candidate based on postoperative PTH (normal PTH after 2-4weeks). Associations of ATX candidate status with demographic and clinical attributes were studied. 268 had a reoperative (49%) or subtotal PTX with ATX. 151 had data for PTH analysis, and 21 (14%) were identified as candidates for ATX. The mean % decline in IOPTH from baseline to 20min post-excision was 51% in noncandidates vs 73% in candidates (P = .002). The mean change in IOPTH from baseline to final was 52% in noncandidates and 83% in candidates (P = .009). A decrease in IOPTH from baseline to 20min post-excision of 23.4% or greater or a final PTH of 52pg/mL or less would be an indication for ATX. Of the 21 who needed an ATX, it failed in 10. Parathyroid ATX is frequently unnecessary, and the viability is less than expected. While candidates for ATX have a greater IOPTH % decline at all points during surgery and a lower final IOPTH, the clinical practicality of using IOPTH to determine ATX candidacy is limited.

Prospective evaluation of perioperative biochemical investigations to predict hypocalcemia after total or near total thyroidectomy

Hypocalcemia is one of the common complications after total thyroidectomy. In these patients, the serum parathyroid hormone (PTH), calcium level decreases, and the phosphorus level increases. The level of fibroblast growth factor-23 (FGF-23), a phosphaturic hormone, increases in the serum to normalize the serum phosphorus level. In our study, we aimed to investigate the predictive values of PTH, calcium, phosphorus, 1,25-dihydroxy vitamin D (vitamin D), and FGF-23 tests in revealing patients who will develop hypocalcemia after thyroidectomy. Fifty-seven patients undergoing total thyroidectomy (fifty-two with multinodular goiter, three with Graves’ disease and two with papillary thyroid cancer) were included in this prospective study. Serum PTH, calcium, phosphorus, and vitamin D levels of the patients were measured preoperatively. Ten minutes after complete removal of the thyroid gland, intraoperative PTH (IOPTH) level was measured and the amount of decline in PTH level (PTH decline) was calculated. Postoperative PTH, calcium, phosphorus, vitamin D, and FGF-23 levels were measured 24 h after the operation. Postoperatively, hypocalcemia developed in 7(12.3%) of the 57 patients. IOPTH, postoperative PTH, calcium, and vitamin D levels were significantly lower and PTH decline was significantly higher in patients with postoperative hypocalcemia. Postoperative FGF-23 levels were similar between the groups (p 0.952).

BIOCHEMICAL WITH NORMAL PARATHYROID HORMONE : A CASE REPORT

Normo-hormonal primary hyperparathyroidism(NPHPT) is an uncommon condition which has been increasing in last decade. This milder biochemical entity remains incompletely understood due to lack of long term health outcomes regarding management. NPHPT poses two challenges to the surgeon, rst is when to operate and second is the use of intra-operative parathyroid hormone assay to predict the success of surgery. Here we present a 53 year old lady who came with low back ache of more than 2 years duration. It is found to have elevated calcium levels and on further evaluation found to have high normal parathyroid hormone levels in two occasions. Pre operative localization studies were done by suspecting normo-hormonal hyperparathyroidism which showed concordant lesions in both ultrasound neck and Sestamibi scan. She underwent focused parathyroidectomy with intra-operative parathyroid hormone levels which dropped in to less than 30pg/ml. Postoperative calcium was within normal limits and she was symptomatically better. In patients with symptoms of hypercalcemia, elevated calcium levels and high normal intact parathyroid hormone levels should be considered as inappropriate and should lead to the suspicion of normo-hormonal hyperparathyroidism. Intra operative parathyroid hormone levels below 30pg/ml can be utilized as an indicator of successful operation in normo-hormonal hyperparathyroidism.In symptomatic hypercalcemic patients, even if the parathyroid hormones are high normal, a further investigation should be done to locate the parathyroid adenoma and surgery is the best cure

Influence of the position and size of the hyperfunctioning parathyroid gland on intraoperative PTH levels collected from the ipsilateral jugular and peripheral veins

Influence of the position and size of the hyperfunctioning parathyroid gland on intraoperative PTH levels collected from the ipsilateral jugular and peripheral veins

ODP115 Primary Hyperparathyroidism in Pregnancy

Abstract Introduction Primary hyperparathyroidism (HPT) is characterized by an overproduction of parathyroid hormone (PTH) by a parathyroid adenoma, parathyroid hyperplasia, or parathyroid carcinoma classically causing hypercalcemia. Incidence of this pathology during pregnancy is very low (1%), as the great majority of cases are diagnosed in adults &amp;gt;45 years old. When present,it can be associated with detrimental maternal and fetal outcomes. Complications may include maternal nephrolithiasis, hyperemesis, and pancreatitis, along with miscarriage, fetal demise, low birth weight, neonatal hypocalcemia, and tetany. Considering the incidence of HPT in pregnancy is uncommon, there is limited data regarding diagnostic and treatment options for these patients. Clinical Case This is the case of a 28-year-old pregnant female at 12 weeks gestational age (WGA) who had a history of Type 1 Diabetes Mellitus. She was evaluated regarding metabolic control during pregnancy, however, was incidentally found with hypercalcemia. She denied any history of fractures, abdominal discomfort, bone pains or nephrolithiasis; she also had no pertinent family history associated with hypercalcemia. Laboratories showed a calcium level of 14.9 md/dL (nl, 8.6-10.2) with a phosphorus level of 1.9 mg/dL (nl, 2.5-4.5), which raised the suspicion of HPT. Further workup demonstrated high parathyroid hormone (PTH) 245 pg/mL (nl, 18.4-80.1), vitamin D-25-OH 24.7 ng/mL (nl, 30-100) and 24hr urine calcium collection of 402.5 mg/24hr (nl, 100-300); the latter excluding the possibility of familial hypocalciuric hypercalcemia. Patient was managed conservatively with IV hydration resulting in mild improvement of calcium to 12.4 mg/dL. Thyroid/Neck ultrasound revealed a thyroid gland with normal homogeneous texture and no distinct focal vascularized structure to suggest parathyroid origin. Other diagnostic imaging for localization of parathyroid disease with technetium-99m methoxyisobutylisonitrile parathyroid scintigraphy or single-photon emission Computed Tomography are not recommended in pregnancy due to insufficient safety data and radiation risk. After discussion with a multidisciplinary team including endocrine surgeons, endocrinologists, and obstetricians, an exploratory neck surgery for possible parathyroidectomy was recommended. She underwent surgery at 13 WGA where a left superior adenoma was identified and completely removed without complications. Intraoperative PTH levels revealed a pre-excision PTH of 342 pg/mL (18.4-80.1), post-excision PTH at 5 minutes of 76 pg/mL, and at 10 minutes of 50 ng/mL, suggestive of successful surgical removal. Pathology report was consistent with left superior parathyroid adenoma. Both calcium and phosphorus levels normalized post-surgery [Ca 9.6 mg/dL (nl, 8.6-10.2) and 2.7 mg/dL (2.5-4.5)]. Conclusion This is an unusual case of a patient with asymptomatic severe hypercalcemia associated to HPT diagnosed during pregnancy. In this patient conservative medical treatment proved to be unsuccessful. Parathyroidectomy early on the 2 nd trimester was advantageous to avoid both maternal and fetal complications during pregnancy. Presentation: No date and time listed

Late Recurrence of Hyperparathyroidism: Parathyromatosis or Recurrent Parathyroid Carcinoma?

A middle-aged woman presented with elevated calcium (10.7 mg/dL [0.28 mmol/L]) and parathyroid hormone (131 pg/mL [4,663.6 pmol/L]) levels. A sestamibi scan exhibited a right upper parathyroid lesion. Parathyroidectomy revealed a 3152 mg right upper parathyroid gland and the intraoperative parathyroid hormone level decreased by 90% (from 27.1 to 2.6 pmol/L; reference range, 1.3-6.8 pmol/L). The lesion was removed intact without any “spillage.” Histology revealed hypercellular parathyroid with intravascular tumor clusters at the periphery of the main lesion.

PSAT202 A Rare Case of Four-Gland Parathyroid Adenomas

Abstract Background Amongst patients diagnosed with primary hyperparathyroidism, 80% have been identified to have a single parathyroid gland involvement, with 10% involving two glands or more. Case A 71-year-old female with medical history of hypothyroidism, multinodular goiter, CKD stage 3a, recurrent nephrolithiasis and hyperparathyroidism presented for evaluation of hypercalcemia. She was diagnosed with hyperparathyroidism 9 years prior to presentation however she preferred medical management with cinacalcet. For the past 5 months, she had been experiencing worsening fatigue, constipation, body aches and appetite loss. Further blood analysis revealed PTH 1176 pg/mL (14-64 pg/mL), TSH 2.69 uU/mL (0.35-4.94 uU/mL), free T4 1.12 ng/dL (0.60-1.89 ng/dL), vitamin D, 25-Hydroxy 24 ng/mL (30-80 ng/mL), serum calcium 12.6 mg/dl (8.9-10.4 mg/dL), ionized calcium 1.65 mmol/L (1.14-1.33 mmol/L), phosphorus 1.9 mg/dl (2.4-4.8 mg/dl), magnesium 1.0 mg/dl (1.8-3.0 mg/dL). Thyroid ultrasound revealed a left isthmus heterogenous solid nodule measuring up to 2.0 cm and a separate nodule superior to the isthmus measuring up to 0.6 cm. Subsequent NM parathyroid scan was limited due to diffuse uptake of enlarged nodular thyroid. Although limited, imaging did reveal a small focus of uptake lateral to the right lower pole concerning for parathyroid adenoma. A CT 4D neck with and without contrast demonstrated a suspicious parathyroid adenoma posterior to the inferior aspect of the left thyroid measuring up to 1.7 cm, an additional 0.8 cm questionable node, and a 4 cm multicystic mass inferior to the right thyroid lobe concerning for exophytic thyroid nodule or multi cystic parathyroid adenoma. Due to persistence of symptoms and significantly elevated PTH levels concerning for carcinoma, decision was made to undergo a four-gland parathyroid exploration and a right hemithyroidectomy. A right superior parathyroid adenoma was identified; after resection, intraoperative PTH levels failed to improve which prompted further exploration. Left superior and inferior parathyroid adenomas were identified and resected. An ectopic nodule located in the right superior mediastinum with surrounding normal parathyroid tissue was identified and dissected, leaving parathyroid tissue behind. Post operatively, PTH levels appropriately decreased to 54 pg/ml. Pathology of identified parathyroid glands had hypercellular parathyroid tissue with fibrous capsule, consistent with adenomas. Interestingly, the pathology of the presumed ectopic nodule was consistent with atypical parathyroid adenoma. Immunostatins with parafibromin demonstrated nuclear immunoreactivity in the lesional cells, consistent with a benign neoplasm. Patient developed symptomatic hypocalcemia following surgery. She was gradually weaned off calcitriol and is currently normocalcemic. Conclusion It is extremely rare to have adenoma of 4 parathyroid glands simultaneously in the absence of genetic conditions associated with hyperparathyroidism. Age of onset of hyperparathyroidism and absence of other endocrine abnormalities clinically was reassuring, however; further biochemical and genetic testing will be considered in this patient. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

PSAT215 Hypercalcemic Crisis Complicating a First Trimester Pregnancy Caused by a Giant Parathyroid Adenoma Masquerading as a Thyroid Nodule

Abstract Background Primary hyperparathyroidism (PHP) during pregnancy is rare with a reported incidence of 1%, although the true incidence is unknown. It is associated with increased morbidity and mortality for both mother and fetus. Most reported cases of PHP during pregnancy are due to small adenomas causing mild hyperparathyroidism. Surgical management is recommended if the calcium level is &amp;gt;11mg/dL (2.75mmol/L) or the patient has symptomatic hypercalcemia. It is generally recommended that surgery be performed in the second trimester due to the risk of miscarriage in the first trimester, and preterm labor in the third trimester. Case A 29-year-old woman presented to our emergency department at 10 weeks’ gestation with nausea and vomiting. She also reported constipation and fatigue. On examination, she was euvolemic, awake and alert, with no neurological symptoms or signs. The suspected diagnosis was hyperemesis gravidarum until her laboratory evaluation revealed marked hypercalcemia [15.6mg/d (3.9mmol/L)]. Further labs revealed hypophosphatemia [1.2mg/dL (0.39mmol/L)], hypokalemia [3.3mEq/L], hypomagnesemia [1.4mEq/L], low 25-hydroxy vitamin D [16.2ng/mL (40.44pmol/L)], and elevated intact parathyroid hormone (iPTH) [573pg/mL], 1,25-dihydroxy vitamin D [251.1pg/mL (626.75pmol/L)], and 24 hour urinary calcium [448mg/24 hours (11.2mmol/24 hours]. On cardiac evaluation, her QTc was normal. The patient was given intravenous hydration with normal saline, which reduced the calcium to 13.6mg/dL (3.4mmol/L) after 48 hours. She remained symptomatic and severely hypercalcemic, so calcitonin 4 IU/kg every 12 hours was added, while a neck ultrasound was performed to localize the parathyroid adenoma. Her calcium level decreased to 10.7mg/dL (2.7mmol/L) after calcitonin, but rapidly rebounded to 13.3mg/dL (3.3mmol/L) along with hypophosphatemia and hypokalemia. Intravenous potassium phosphate was initiated and her calcium decreased to 11.8mg/dL (2.95mmol/L). The neck ultrasound did not identify a parathyroid adenoma, but identified a 2.5×1.5×3.3 cm right mixed cystic/ solid thyroid nodule. An MRI of the neck revealed two right thyroid nodules. The decision was made to perform a neck dissection given the persistent severe hypercalcemia after a multidisciplinary team evaluation, and extensive discussion with the patient. The surgical exploration of the right neck identified a giant parathyroid adenoma that weighed 11.3g. The intraoperative PTH levels reduced from 804pg/mL to 60.7pg/mL. Her calcium normalized immediately postoperatively and she was discharged home without complication. At the time of last follow up, she was 18 weeks’ gestation and a fetal ultrasound was normal. Discussion This case had three unusual features: PHP causing severe hypercalcemia during pregnancy; a giant parathyroid adenoma; and parathyroid adenoma masquerading as a thyroid nodule on imaging. This case highlights the importance of a multidisciplinary team approach in optimizing the care of such complicated patients, along with the need for definitive surgical intervention. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Measurement of Parathyroid Hormone Level after Total Thyroidectomy in Prediction of Hypocalcaemia

Background: Parathyroid dysfunction leading to symptomatic hypocalcemia is not uncommon following a total or completion thyroidectomy and is often associated with significant patient morbidity and a prolonged hospital stay. Objectives: To investigate whether postoperative parathyroid hormone level is a parameter to identify hypocalcaemia after total thyroidectomy. Methods: This prospective longitudinal study was carried out with variety of thyroid disorders with indication of total thyroidectomy at BSMMU. Total 103 patient were selected following the inclusion and exclusion criteria. The routine clinical assessment and the preoperative laboratory investigations of the study population were performed before operation. Preoperative and postoperative levels of serum PTH and serum calcium level were measured. Results: Immediate post-operative period 17(16.50%) patients PTH level were low (&lt;14 pg/ ml). The mean PTH in immediate post-operative was 36.79±21.71 pg/ml. Regarding the distribution of the study patients by serum calcium, it was observed that 20.39% patients belonged to low (&lt;8 mg/dl) serum calcium. The mean serum calcium level was 8.47±1.19 (mg/dl) with ranged from 2.1 to 10.6 (mg/dl). Among the study population 11 patient developed symptomatic hypocalcemia. Most 72.7% the patient, symptomatic hypocalcemia developed after 48 hours of operation. Conclusion: Hypocalcaemia after total or completion thyroidectomy is not uncommon in our population. If we measure a single parathyroid hormone level in postoperative period that can reflect early result and help to take necessary measure to avoid hypocalcaemic effect. Low intraoperative PTH levels during thyroid surgery are therefore a feasible predictor of postoperative hypocalcemia. Sir Salimullah Med Coll J 2022; 30: 103-107