Treatment of hypocalcemia in hungry bone syndrome: A case report

Surgical treatment of secondary hyperparathyroidism in children with chronic kidney disease. Experience in 19 patients

OBJECTIVES

Secondary hyperparathyroidism (sHPT) is an important contributor to bone disease and cardiovascular calcifications in children with chronic kidney disease (CKD). When conservative measures are ineffective, parathyroidectomy is indicated. The aim of our study was to evaluate the efficacy and safety of subtotal parathyroidectomy (sPTX) in pediatric and adolescent patients, and to provide a rationale for considering this aggressive treatment in CKD patients with uncontrolled sHPT.

METHODS

We retrospectively analyzed the medical records of 19 pediatric CKD patients on dialysis with refractory sHPT who underwent sPTX at our institution between 2010 and 2020. All patients had clinical, radiological, and biochemical signs of renal osteodystrophy.

RESULTS

One year after sPTX, parathyroid hormone (PTH) levels (median and interquartile range (IQR)) dropped from 2073 (1339-2484) to 164 (93-252) pg/mL (p=0.0001), alkaline phosphatase (ALP) levels from 1166 (764-2373) to 410 (126-421) IU/L (p=0.002), and the mean (±SDS) calcium-phosphate (Ca*P) product from 51±11 to 41±13 mg2/dL2 (p=0.07). Postoperatively, all patients presented with severe hungry bone syndrome (HBS) and required intravenous and oral calcium and calcitriol supplementation. None of them had other postoperative complication. Histological findings had a good correlation with preoperative parathyroid ultrasound imaging (n: 15) in 100 % and with technetium-99m (99mTc) sestamibi scintigraphy (n: 15) in 86.6 %. Clinical and radiological signs of bone disease improved in all patients.

CONCLUSIONS

Pediatric sPTX is effective and safe to control sHPT and calcium-phosphate metabolism in children with CKD on dialysis and may mitigate irreversible bone deformities and progression of cardiovascular disease.

Hypercalcemic Crisis Due to a Giant Intrathyroidal Parathyroid Adenoma, with Postsurgical Severe Hypocalcemia and Hungry Bone Syndrome: A Case Report

BACKGROUND

Parathyroid adenoma is the most common cause of hypercalcemia and rarely leads to a hypercalcemic crisis, which is an unusual endocrine emergency that requires timely surgical excision.

CASE PRESENTATION

A 67-year-old male was admitted to the ER of the Euroclinic Hospital, Athens, Greece, because of elevated calcium levels and a palpable right-sided neck mass, which were accompanied by symptoms of nausea, drowsiness, and weakness for six months that increased prior to our evaluation. A gradual creatinine elevation and decreasing mental state were observed as well. The initial laboratory investigation identified severely elevated serum calcium (3.6 mmol/L) levels consistent with a hypercalcemic crisis (HC) and parathyroid hormone PTH (47.6 pmol/L) due to primary hyperparathyroidism. Neck ultrasonography (USG) identified a large, well-shaped cystic mass in the right thyroid lobe. With a serum calcium concentration of 19.5 mg/dL and a PTH of 225.3 pmol/L, the patient underwent partial parathyroidectomy and total thyroidectomy, which decreased serum calcium and PTH to 2.5 mmol/L and 1.93 pmol/L, respectively. Histology revealed a giant intrathyroidal cystic parathyroid adenoma, which was responsible for the hypercalcemic crisis. Postoperatively, the patient developed severe biochemical and clinical hypocalcemia, with calcium concentrations as low as 1.65 mmol/L, consistent with hungry bone syndrome (HBS), which was treated with high doses of intravenous calcium gluconate and oral alfacalcidol, and a slow recovery of serum calcium. After discharge, parathyroid function recovered, and symptomatology resolved entirely in more than one month.

DISCUSSION/CONCLUSIONS

We present a case involving an exceptionally large intrathyroidal parathyroid adenoma that is characterized by clinical manifestations that mimic malignancy. The identification and treatment of such tumors is challenging and requires careful preoperative evaluation and postoperative care for the risk of hungry bone syndrome.

Intensive Calcium Monitoring Following Parathyroidectomy: Prevention of Hungry Bone Syndrome in Children

Cite this article as: García Díaz FJ, Martin LB, Gómez Gila AL, Navarro Moreno C. Intensive calcium monitoring following parathyroidectomy: Prevention of hungry bone syndrome in children. Turk Arch Pediatr. 2024;59(1):109-111.

Persistent Primary Hyperparathyroidism Secondary to an Ectopic Mediastinal Adenoma in a Young Adult: A Case Report

Primary hyperparathyroidism commonly affects elderly women. When present in the young population, it is usually asymptomatic, most frequently due to a parathyroid adenoma and the definitive management is surgical excision. Uncommonly, 5-10% of patients fail to achieve long-term cure after initial parathyroidectomy and 6-16% of them is due to an ectopic parathyroid adenoma that will require focused diagnostic and surgical approaches. We report a 21-year-old male who had bilateral thigh pain. Work-up revealed bilateral femoral fractures, brown tumors on the arms and multiple lytic lesions on the skull. Serum studies showed hypercalcemia (1.83 mmol/L), elevated parathyroid hormone [(PTH) 2025.10 pg/mL], elevated alkaline phosphatase (830 U/L), normal phosphorus (0.92 mmol/L) and low vitamin D levels (18.50 ng/mL). Bone densitometry showed osteoporotic findings. Sestamibi scan showed uptake on the left superior mediastinal region consistent with an ectopic parathyroid adenoma. Vitamin D supplementation was started pre-operatively. Patient underwent parathyroidectomy with neck exploration; however, the pathologic adenoma was not visualized and PTH levels remained elevated post-operatively. Chest computed tomography with intravenous contrast was performed revealing a mediastinal location of the adenoma. A repeat parathyroidectomy was done, with successful identification of the adenoma resulting in a significant drop in PTH and calcium levels. Patient experienced hungry bone syndrome post-operatively and was managed with calcium and magnesium supplementation. A high index of suspicion for an ectopic adenoma is warranted for patients presenting with hypercalcemia and secondary osteoporosis if there is persistent PTH elevation after initial surgical intervention. Adequate follow-up and monitoring is also needed starting immediately in the post-operative period to manage possible complications such as hungry bone syndrome.

Forestalling Hungry Bone Syndrome after Parathyroidectomy in Patients with Primary and Renal Hyperparathyroidism

Hungry bone syndrome (HBS), severe hypocalcemia following parathyroidectomy (PTX) due to rapid drop of PTH (parathormone) after a previous long term elevated concentration in primary (PHPT) or renal hyperparathyroidism (RHPT), impairs the outcome of underlying parathyroid disease.

OBJECTIVE

overview HBS following PTx according to a dual perspective: pre- and post-operative outcome in PHPT and RHPT. This is a case- and study-based narrative review.

INCLUSION CRITERIA

key research words "hungry bone syndrome" and "parathyroidectomy"; PubMed access; in extenso articles; publication timeline from Inception to April 2023.

EXCLUSION CRITERIA

non-PTx-related HBS; hypoparathyroidism following PTx. We identified 120 original studies covering different levels of statistical evidence. We are not aware of a larger analysis on published cases concerning HBS (N = 14,349). PHPT: 14 studies (N = 1545 patients, maximum 425 participants per study), and 36 case reports (N = 37), a total of 1582 adults, aged between 20 and 72. Pediatric PHPT: 3 studies (N = 232, maximum of 182 participants per study), and 15 case reports (N = 19), a total of 251 patients, aged between 6 and 18. RHPT: 27 studies (N = 12,468 individuals, the largest cohort of 7171) and 25 case reports/series (N = 48), a total of 12,516 persons, aged between 23 and 74. HBS involves an early post-operatory (emergency) phase (EP) followed by a recovery phase (RP). EP is due to severe hypocalcemia with various clinical elements (<8.4 mg/dL) with non-low PTH (to be differentiated from hypoparathyroidism), starting with day 3 (1 to 7) with a 3-day duration (up to 30) requiring prompt intravenous calcium (Ca) intervention and vitamin D (VD) (mostly calcitriol) replacement. Hypophosphatemia and hypomagnesiemia may be found. RP: mildly/asymptomatic hypocalcemia controlled under oral Ca+VD for maximum 12 months (protracted HBS is up to 42 months). RHPT associates a higher risk of developing HBS as compared to PHPT. HBS prevalence varied from 15% to 25% up to 75-92% in RHPT, while in PHPT, mostly one out of five adults, respectively, one out of three children and teenagers might be affected (if any, depending on study). In PHPT, there were four clusters of HBS indicators. The first (mostly important) is represented by pre-operatory biochemistry and hormonal panel, especially, increased PTH and alkaline phosphatase (additional indicators were elevated blood urea nitrogen, and a high serum calcium). The second category is the clinical presentation: an older age for adults (yet, not all authors agree); particular skeleton involvement (level of case reports) such as brown tumors and osteitis fibrosa cystica; insufficient evidence for the patients with osteoporosis or those admitted for a parathyroid crisis. The third category involves parathyroid tumor features (increased weight and diameter; giant, atypical, carcinomas, some ectopic adenomas). The fourth category relates to the intra-operatory and early post-surgery management, meaning an associated thyroid surgery and, maybe, a prolonged PTx time (but this is still an open issue) increases the risk, as opposite to prompt recognition of HBS based on calcium (and PTH) assays and rapid intervention (specific interventional protocols are rather used in RHPT than in PHPT). Two important aspects are not clarified yet: the use of pre-operatory bisphosphonates and the role of 25-hydroxyitamin D assay as pointer of HBS. In RHPT, we mentioned three types of evidence. Firstly, risk factors for HBS with a solid level of statistical evidence: younger age at PTx, pre-operatory elevated bone alkaline phosphatase, and PTH, respectively, normal/low serum calcium. The second group includes active interventional (hospital-based) protocols that either reduce the rate or improve the severity of HBS, in addition to an adequate use of dialysis following PTx. The third category involves data with inconsistent evidence that might be the objective of future studies to a better understanding; for instance, longer pre-surgery dialysis duration, obesity, an elevated pre-operatory calcitonin, prior use of cinalcet, the co-presence of brown tumors, and osteitis fibrosa cystica as seen in PHPT. HBS remains a rare complication following PTx, yet extremely severe and with a certain level of predictability; thus, the importance of being adequately identified and managed. The pre-operatory spectrum of assessments is based on biochemistry and hormonal panel in addition to a specific (mostly severe) clinical presentation while the parathyroid tumor itself might provide useful insights as potential risk factors. Particularly in RHPT, prompt interventional protocols of electrolytes surveillance and replacement, despite not being yet a matter of a unified, HBS-specific guideline, prevent symptomatic hypocalcemia, reduce the hospitalization stay, and the re-admission rates.

Occult Pulmonary Neuroendocrine Tumor Causing Severe Hyperparathyroidism: Diagnostic Challenges and Clinical Outcomes

Background/Objective

Ectopic tumoral production of parathyroid hormone (PTH) is rare. The incidence of hyperparathyroidism and osteitis fibrosa cystica (OFC) secondary to ectopic PTH secretion has only been reported in case reports, although infrequent.

Case Report

We report a case of a well-differentiated pulmonary neuroendocrine tumor (NET) producing PTH that presented with severe hypercalcemia and OFC. Surgical removal of the pulmonary tumor resulted in resolution of hypercalcemia. Immunocytochemical analysis of the tumor tissue revealed PTH-positive staining. Recovery was complicated by severe hypocalcemia due to hungry bone syndrome.

Discussion

To the best of our knowledge, this is the first documented case of a pulmonary NET causing OFC via PTH. We further describe the successful identification and resection of a rare NET and restoration of calcium homeostasis with aggressive calcium and vitamin D repletion.

Conclusion

Although a rare cause of severe hypercalcemia and OFC, ectopic tumoral production of PTH must be considered in the differential diagnosis. Furthermore, resection of these tumors secreting PTH can lead to a protracted and severe high risk of hungry bone syndrome, which requires aggressive treatment to maintain calcium homeostasis.

Hungry Bone Syndrome Secondary to Subtotal Thyroidectomy in A Patient With Thyrotoxicosis

Patients with thyrotoxicosis are prone to transient hypocalcemia after thyroidectomy, which may be due in part to surgical damage to the parathyroid glands. Hungry bone syndrome (HBS) can also cause hypocalcemia after thyroidectomy. HBS is due to increased osteoblast-mediated bone formation activity and normal or decreased bone resorption activity. As HBS is uncommon in patients after thyroidectomy, we herein present a case of hypocalcemia secondary to HBS after subtotal thyroidectomy for thyrotoxicosis in a 25-year-old woman with a two-month history of tingling extremities and carpopedal spasms after subtotal thyroidectomy for thyrotoxicosis. Diagnostic tests showed hypocalcemia and hyperphosphatemia with elevated parathyroid hormone levels and moderately decreased serum 25-hydroxyvitamin D levels. In addition to thyroid hormone replacement therapy, she was given calcitriol and Caltrate D (600 mg calcium plus 125 IU cholecalciferol). After two months of treatment, she no longer had spasms and her paresthesia improved. Meanwhile, serum electrolytes and parathyroid hormone levels had almost returned to the normal ranges. This is a rare case of HBS presented as a complication of subtotal thyroidectomy in a patient with thyrotoxicosis.

Intensive calcium monitoring improves outcomes on hungry bone syndrome in hyperparathyroidism

Objectives. Hungry bone syndrome (HBS) is a severe and underdiagnosed complication of parathyroidectomy in the treatment of primary hyperparathyroidism (PHP) and secondary hyper-parathyroidism to chronic kidney disease (SHP-CKD).Methods. A longitudinal study was conducted to compare the postoperative outcomes of patients who developed HBS in two different time frames: before and after implementing a protocol with an intensive electrolytic monitoring and an algorithm regarding electrolytic supplementation.Results. Overall, 77 parathyroidectomies were included. In PHP, a protocol implementation led to an increased admission of patients in the Intermediate Care Unit for intensive electrolytic monitoring (p<0.001) and an increased rate of oral calcium replacement during hospital stay (p=0.013) compared to pre-protocol era. In SHP-CKD, duration of intravenous calcium replacement was reduced (p=0.010). The prevalence of HBS (9.8% in PHP and 58.3% in SHP-CKD) was similar between the two periods, although its diagnosis had an increased trend in PHP since the protocol implementation. None of the diagnosis of HBS was established due to hypocalcemic symptoms in the post-protocol era (contrary to pre-protocol period, p=0.021). Both hypocalcemia length and duration of surgical ward hospitalization were reduced (p=0.047 and p=0.042, respectively).Conclusions. An improved assessment of hyperparathyroidism and a decrease in HBS severity were noted in the post-protocol era. We strongly recommend the implementation of a standardized protocol with an intensive phosphocalcium monitoring in the high-risk patients who undergo parathyroidectomy due to hyperparathyroidism as it improves the health care and management of HBS.

Role of Vitamin D Supplements in Prevention of Hungry Bone Syndrome after Successful Parathyroidectomy for Primary Hyperparathyroidism: A Prospective Study

BACKGROUND

We postulated that the preoperative correction of vitamin D levels can significantly reduce the incidence of hunger bone syndrome among patients undergoing parathyroidectomy for primary hyperparathyroidism.

METHODS

We performed a prospective, randomized, open-label study on 102 patients with primary hyperparathyroidism and coexisting vitamin D deficiency who were scheduled to undergo parathyroidectomy. Patients were divided into the following two groups: group I which included 52 patients who did not receive preoperative vitamin D supplementation; and group II which included 50 patients who received cholecalciferol 1000-2000 IU daily or 50000 IU weekly until they achieve vitamin D levels >20 ng/mL (group IIa = 25 patients) or vitamin D levels >30 ng/mL (group IIb = 25 patients).

RESULTS

The incidence of hunger bone syndrome in group IIb was lower than group I and group IIa (8% versus 16% versus 23%, respectively); however, this difference did not reach the level of statistical significance (p = 0.22). Patients with hunger bone syndrome were significantly younger and had higher serum phosphorus, alkaline phosphatase, magnesium, and bone mineral density at baseline than patients without hunger bone syndrome. On the other hand, patients with hunger bone syndrome had significantly lower 25-hydroxyvitamin D at baseline than patients without hunger bone syndrome (p = 0.001). The ROC curve showed that the baseline level of serum 25-hydroxyvitamin D was not an independent discriminator of hunger bone syndrome (area under curve = 0.21 (95% CI: 0.06-0.34); p = 0.011).

CONCLUSION

Preoperative course of vitamin D supplements has no preventive role on the postoperative incidence of hunger bone syndrome among patients with primary hyperparathyroidism and coexisting vitamin D deficiency undergoing parathyroidectomy.

Fatal Hypocalcaemia Due to Hungry Bone Syndrome with Secondary Refractory HyperParathyroidism after Parathyroidectomy: A Case Report

Introduction

Hungry bone syndrome (HBS) refers to the rapid, profound, and prolonged hypocalcaemia associated with hypophosphatemia and hypomagnesaemia, and is exacerbated by suppressed parathyroid hormone (PTH) levels, which follows parathyroidectomy in patients with severe primary hyperparathyroidism (PHPT) and preoperative high bone turnover. [1]

Case report

This report concerns a dialysed patient who underwent surgical treatment for secondary refractory hyperparathyroidism. Haemodialysis was carried out pre-operatively, and subsequently, a total parathyroidectomy with auto-transplantation of parathyroid tissue in the sternocleidomastoid muscle (SCM) was performed. Rapid and progressive hypocalcaemia symptoms developed during the second day postoperatively. Acute cardiac symptoms with tachyarrhythmia, haemodynamic instability and finally asystole occurred, which required cardiopulmonary resuscitation (CPR). The ionic calcium level was 2.2 mg/dL being consistent with a diagnosis of HBS. A second cardiac arrest unresponsive to CPR followed an initial period of normal sinus rhythm. Death ensued shortly after. Before death, the ionic calcium was 3.1 mg/dL.

Conclusion

HBS, after parathyroidectomy in patients with secondary hyperparathyroidism (SHPT), may be severe, prolonged and sometimes fatal. Generally, HBS symptomatology is that of a mild hypocalcaemia. It can, however, include heart rhythm disturbances with haemodynamic alterations requiring intensive care measurements and even cardiopulmonary resuscitation. A close clinical and laboratory post-parathyroidectomy monitoring of dialysed patients is of the utmost importance.