Successful Management of Severe Hypercalcemia with Zoledronic Acid: A Report of Two Pediatric Cases

Severe hypercalcemia associated with vitamin D intoxication or malignancy in children is a rare and life-threatening condition. There is little published experience with Zoledronic acid in the treatment of pediatric severe hypercalcemia. Here, we present two pediatric cases of severe hypercalcemia, one due to vitamin D intoxication and the second to malignancy, in which Zoledronic acid was used as the first-line bisphosphonate in the treatment. While both cases responded well to a single dose of Zoledronic acid, the second case experienced hypocalcemia requiring calcium treatment after Zoledronic acid infusion. Our report shows that Zoledronic acid may be an effective option in the treatment of severe pediatric hypercalcemia, although patients should be followed closely after infusion due to the risk of hypocalcemia. We provide additional published evidence for the effectiveness of Zoledronic acid in correcting severe pediatric hypercalcemia and hope this will encourage future studies with larger numbers of patients.

Hypercalcemia of Malignancy: Time to Pull the Brakes

Hypercalcemia of malignancy (HOM) is usually seen in advanced stage and carries a poor prognosis. Survival outcomes are dismal and most of the patients are unable to receive subsequent definite anti-cancer therapy. There is lack of any retrospective or prospective data regarding hypercalcemia of malignancy in Indian population. We aim to describe survival outcomes in hypercalcemia associated with solid organ malignancies. Forty-five patients diagnosed with HOM associated with solid organ malignancies were included in the study. Patients were followed up till death. Clinical features and survival outcomes were noted. Squamous cell carcinoma of head and neck region and lung comprised most of the cases associated with HOM. Most of the patients presented with poor performance status. Median overall survival (OS) was 20 days (2-78 days). Median OS was 35 days (9-58 days) in those who received definite anti-cancer therapy. Four-week mortality rate was estimated as 59.5%, while this increased to 75.7% within 6 weeks from the diagnosis of hypercalcemia. Survival outcomes are poor after the diagnosis of hypercalcemia in cancer patients. Best supportive care including hospice care should be strongly considered at this point of time instead of definite systemic anti-cancer therapy.

Treatment of Hypercalcemia of Malignancy

The treatment of hypercalcemia of malignancy (HCM) consists of enhancing renal calcium excretion, mostly through hydration with isotonic fluids and the use of antiresorptive therapies. Intravenous zoledronic acid is currently the first-line treatment. Subcutaneous denosumab is used for bisphosphonate-refractory hypercalcemia and in patients with renal failure. There is no evidence that bisphosphonates prevent the occurrence of HCM. Conversely, denosumab, compared with zoledronic acid, is associated with a lower risk of HCM, both first episode and recurrence, in patients with breast cancer and multiple myeloma.

Hypercalcemia Owing to Overproduction of 1,25-Dihydroxyvitamin D3 in Fetal Lung Adenocarcinoma: Case Report

Hypercalcemia is a common electrolyte abnormality in malignancy and is largely caused by activation of parathyroid hormone (PTH) pathways. We report the case of a 76-year-old man with hypercalcemia primarily owing to 1,25-dihydroxyvitamin D₃ overproduction from a high-grade fetal lung adenocarcinoma. Histologically, the tumor itself and tumor-adjacent macrophages were positive for the CYP27B1 protein, a key enzyme that generates 1,25-dihydroxyvitamin D₃. Suppression was observed in serum PTH and PTH-related hormone levels, suggesting hypercalcemia is independent of the PTH pathway. Serum calcium level returned to normal after surgical resection of the lung cancer, supporting extrarenal overproduction of 1,25-dihydroxyvitamin D₃ elicited by the tumors is the cause of hypercalcemia in this patient.

Hypercalcemia of malignancy in metastatic esophageal squamous cell carcinoma with simultaneous PTHrP and calcitriol overproduction: A case report with literature review

Introduction and importance

hypercalcemia of malignancy is a severe complication of malignancy and associated with poor prognosis. Four mechanisms are implicated in this metabolic disorder, including excess parathyroid-related peptide secretion, focal osteolysis secondary to bone metastasis or multiple myeloma, excess calcitriol production, and ectopic parathyroid hormone production. Humoral hypercalcemia of malignancy secondary to isolated PTHrP or calcitriol overproduction is known; however, hypercalcemia of malignancy due to simultaneous PTHrP and calcitriol overproduction is less well known.

Case presentation

we report a case of a 63-year-old male who was diagnosed with poorly differentiated esophageal squamous cell carcinoma with simultaneous PTHrP and calcitriol overproduction.

Clinical discussion

while hypercalcemia of malignancy secondary to simultaneous PTHrP and calcitriol secretion has been reported in other solid cancers, this is the first case of humoral hypercalcemia of malignancy secondary to simultaneous PTHrP and calcitriol secretion associated with esophageal cancer. This phenomenon deserves increased recognition as it has both diagnostic and therapeutic consequences. We discuss the current testing algorithm and its limitations in determining the etiology of hypercalcemia of malignancy since it may miss the diagnosis of simultaneous PTHrP and calcitriol production.

Conclusion

we propose a revised testing algorithm for hypercalcemia of malignancy, which may improve the identification of simultaneous overproduction of PTHrP and calcitriol. This new algorithm can better characterize the mechanisms of hypercalcemia of malignancy and more appropriately guide treatment.

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Hypercalcemia of malignancy with simultaneous PTHrP and calcitriol production merits better recognition for both diagnostic and therapeutic purposes.

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A case of hypercalcemia of metastatic esophageal squamous cell carcinoma with simultaneous PTHrP and calcitriol is reported.

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The current testing algorithm and its limitations of hypercalcemia of malignancy is discussed, and a revised one is proposed.

Hypercalcemia of Malignancy Attributed to Cosecretion of PTH and PTHRP in Lung Adenocarcinoma

Introduction

Hypercalcemia of malignancy (HCM) portends a very poor prognosis, and no established guidelines exist regarding its management. Most instances of HCM are due to local osteolysis or secretion of parathyroid hormone related-peptide, while less than 1% of all cases are due to ectopic secretion of parathyroid hormone.

Case Report

We present an unusual case of HCM due to proposed cosecretion of both parathyroid hormone and parathyroid hormone-related protein in a 36-year-old man with a poorly differentiated lung adenocarcinoma. The patient’s hypercalcemia was refractory to conventional measures, including intravenous bisphosphonate therapy (zoledronic acid), and was improved with administration of denosumab.

Conclusion

This is the youngest and first case of hypercalcemia of malignancy attributed to cosecretion of PTH and PTHrP from an adenocarcinoma. In refractory cases of HCM, denosumab is a potential option when other conventional measures are unsuccessful.

Hypercalcemia of Malignancy in a Patient with Hypoparathyroidism: A Complicated but Treatable Condition

Hypercalcemia in hypoparathyroidism has rarely been described. A 55 year-old male patient with primary hypoparathyroidism, left eye melanoma, and Noonan's syndrome, was referred to the endocrinology clinics due to hypoparathyroidism. Laboratories showed serum calcium of 7.8 mg/d, and phosphate 4.8 mg/dl, while using calcium carbonate 1200 mg and vitamin D3 600 IU daily. Calcitriol 0.25 mcg daily was started and calcium carbonate discontinued. Abdominopelvic CT scan and thoracolumbar MRI, showed metastasis to liver, pancreas, and osteolytic lesions in spine, humerus, and ribs. Liver biopsy confirmed metastatic melanoma. Eight weeks later, serum calcium increased to 12 mg/dl. PTH, vitamin D 1,25-OH and PTHrP levels were within the lower range of normal compatible with hypercalcemia of malignancy, secondary to osteolytic disease. Zoledronic acid was added to treat hypercalcemia and bone pain. Our case demonstrates a successful treatment and monitoring of hypocalcemia after administration of bisphosphonate in a patient with hypoparathyroidism.

Corrected calcium versus ionized calcium measurements for identifying hypercalcemia in patients with multiple myeloma

BACKGROUND

Dysregulated bone turnover is an important clinical manifestation of multiple myeloma (MM), and 30% of patients present with hypercalcemia. Serum calcium levels are routinely monitored using total calcium measurements corrected for albumin. However, myeloma-related paraproteins may bind calcium, confounding these measurements.

PATIENTS AND METHODS

We retrospectively analyzed correlation between corrected calcium and ionized calcium in a sample of patients with MM and a control sample of patients with breast or non-small cell lung cancers (n = 200). Multiple linear regression was used to identify variables affecting corrected calcium measurements.

RESULTS

Correlation between corrected calcium and ionized calcium was stronger in the control group compared to the MM group (Spearman correlation coefficient 0.85 versus 0.76, respectively). Sensitivity of corrected calcium in identifying hypercalcemia defined by elevated ionized calcium was 36% in patients with MM and 76% in the control group. Multiple linear regression did not reveal variables significantly influencing corrected calcium in the MM group, although serum paraprotein trended toward significance (p = 0.09).

CONCLUSION

Ionized calcium may be better than corrected calcium for detecting hypercalcemia in patients with MM. Additional analyses are needed to better quantify the clinical impact of paraprotein calcium-binding.

Oncologic Metabolic Emergencies

Cancer and its therapies may lead to several metabolic emergencies that emergency providers (EPs) should be well-versed in identifying and managing. With prompt recognition and treatment initiation in the emergency department, lives can be saved and quality of life maintained. Most oncologic metabolic emergencies occur in advanced cancer states, but some follow initiation of treatment or may be the presenting syndrome that leads to the cancer diagnosis. This article reviews the 2 most emergent oncologic metabolic diagnoses: tumor lysis syndrome and hypercalcemia of malignancy. A discussion on associated cancers and conditions, pathogenesis and pathophysiology, and management recommendations is included.

Denosumab-Associated Severe Hypocalcemia in a Patient With Chronic Kidney Disease

Denosumab is a monoclonal antibody directed against the receptor activator of nuclear factor kappa B ligand (RANKL). Denosumab has been shown to reduce the risk of skeletal-related events, including spinal cord compression, pathologic fracture and hypercalcemia of malignancy in patients with bone metastases. Hypocalcemia is a known side effect of denosumab, occurring in an estimated 8-14% of the patients. Here, we present an asymptomatic patient with stage-5 chronic kidney disease and severe hypocalcemia who had received denosumab 1 month earlier.