Vitamin D-mediated hypercalcemia in lymphoma: evidence for hormone production by tumor-adjacent macrophages

1,25-dihydroxyvitamin D-mediated hypercalcemia associated with solid organ malignancy: a systematic review

INTRODUCTION

A growing amount of evidence has suggested that 1,25-dihydroxyvitamin D [1,25(OH)2D]-mediated hypercalcemia can be found not only in lymphoma and granulomatous disorders, but also in solid organ malignancies. Using systematic review technique, we aimed to summarize all available evidence of possible 1,25(OH)2D-mediated hypercalcemia in patients with solid organ malignancies.

EVIDENCE ACQUISITION

Potentially eligible articles were identified from MEDLINE and EMBASE databases from inception to December 2020 using search strategy consisting of terms related to "Vitamin D," "Hypercalcemia" and "Malignancy." Eligible article must be either case report or case series that reports individual level data of a patient or patients with hypercalcemia associated with solid organ malignancy and elevated 1,25(OH)2D without concomitant conditions that may otherwise explain 1,25(OH)2D-mediated hypercalcemia. Characteristics of the patients were extracted from each study. Eligible cases were categorized into three groups, including "definite," "probable" and "possible" cases, using the criteria to assess the strength of evidence that hypercalcemia observed in the eligible cases was caused by the presence of tumor that resulted in the increased production of 1,25(OH)2D.

EVIDENCE SYNTHESIS

A total of 1673 articles were identified. After systematic review, 17 articles reporting 17 patients with 11 different types of solid organ malignancies associated with hypercalcemia secondary to elevated 1,25(OH)2D were identified. Based on the criteria to assess the strength of evidence of hypercalcemia mediated by tumor-associated increased production of 1,25(OH)2D, there were 4 definite cases and 13 probable cases.

CONCLUSIONS

This systematic review of case reports and case series revealed 17 patients with 11 different types of solid organ malignancies associated with hypercalcemia and elevated 1,25(OH)2D.

Influence of Vitamin D and Its Analogues in Type-B Lymphomas

Lymphomas represent a heterogeneous group of blood tumors, generally divided into non-Hodgkin lymphoma (NHL) (90% of all lymphomas) and Hodgkin lymphoma (HL). High-grade NHL can rapidly progress so that new strategies and potentially therapeutical options are needed. Recently, it was shown that Vitamin D (VitD) inhibits the growth of cancer cells, controls their invasion and metastasis, and strengthens the antitumor activity of various types of chemotherapeutic anticancer agents. Therefore, we reviewed the recent literature about the influence of VitD and its analogues (VDAs) on the treatment and the prognosis of B-cell lymphomas. As to the in vitro studies in different cell lines, VitD3 and VDAs enhanced the anti-proliferative efficacy of various chemotherapeutics and increased the expression of VitD receptor. In in vivo studies, blood levels of VitD were considered: higher values of plasma bioavailable VitD were correlated with better progression-free survival (PFS) and overall survival (OS), while an unfavorable PFS and OS were observed in VitD deficient groups. No clinical trial was made on the analogs, thus confirming the absence of in vivo positive role of these synthetic drugs. In conclusion, higher levels of circulating VitD are related to improved OS, reduced cancer-specific mortality, and better disease-free survival. VitD and analogs showed also positive effects in in vitro studies, while only VitD was able to improve clinical parameters. Furthermore, a complex approach with plant-based diet, adequate levels for motor exercise, and/or eventual VitD supplementation could be a valuable strategy to challenge lymphomas.

Non-parathyroid hypercalcemia in a patient with new-onset hyperthyroidism and silicone-induced granulomas: case report

Background

Hypercalcemia is a frequent occurrence in hospitalized patients. It can vary in presentation and severity, and appropriate treatment requires targeting of the underlying condition. Rarer causes of hypercalcemia, such as hyperthyroidism and granulomatous diseases, need to be addressed after excluding the more prevalent etiologies, namely primary hyperparathyroidism and malignancies. We report a case of moderate hypercalcemia in a patient with HIV-positivity with new-onset autoimmune hyperthyroidism as well as concomitant chronic granulomas due to silicone injections.

Case summary

A 61-year-old patient presented with generalized malaise, asthenia, dyspnea and dysphagia associated with rapid weight loss and recurrent panic attacks. Biochemical work-up revealed moderate hypercalcemia and overt hyperthyroidism with positive anti-TSH-receptor antibodies. Hydration, loop diuretics and methimazole were initiated immediately. Suppressed parathyroid hormone (PTH) levels excluded PTH-mediated hypercalcemia (e.g., primary hyperparathyroidism) and among causes of non-PTH-mediated hypercalcemia, malignancies were excluded. Granulomas secondary to past silicone injections were also found in our patient, however normal 1,25-dihydroxy vitamin D3 levels. Treatment of hyperthyroidism with normalization of thyroid function tests was simultaneously followed by improvement of calcium and PTH levels supporting the diagnosis of hypercalcemia secondary to Graves' disease.

Learning points

Hyperthyroidism is a rare cause of hypercalcemia, but it has to be considered in suggestive clinical settings. In our case, prompt management of Graves' disease contributed to the normalization of calcium levels. This, in turn, supported the differential diagnosis of non-PTH-mediated hypercalcemia.

Emergencies in Hematology: Why, When and How I Treat?

Hematological emergencies are critical medical conditions that require immediate attention due to their rapid progression and life-threatening nature. As various examples, hypercalcemia, often associated with cancers such as multiple myeloma, can lead to severe neurological and cardiac dysfunction. Hyperleukocytosis, common in acute myeloid leukemias, increases the risk of leukostasis and multiorgan failure. Sickle cell crisis, a common complication in sickle cell disease, results from vaso-occlusion, leading to acute pain and tissue ischemia. Tumor lysis syndrome, reported in cases of rapid destruction of cancer cells, causes electrolyte imbalances and acute kidney injury. Acute transfusion reactions, fundamental in hematological conditions, can range from mild allergic responses to severe hemolysis and shock, requiring prompt management. Disseminated intravascular coagulation, involving excessive coagulation and bleeding, is commonly triggered by hematological malignancies, common in the first phases of acute promyelocytic leukemia. Recently, in the era of bispecific antibodies and chimeric antigen receptor T cells, cytokine release syndrome is a manifestation that must be recognized and promptly treated. Understanding the pathophysiology, recognizing the clinical manifestations, and ensuring adequate diagnostic strategies and management approaches for each condition are central to early intervention in improving patient outcomes and reducing mortality.

Vitamin D in Cancer Prevention and Treatment: A Review of Epidemiological, Preclinical, and Cellular Studies

Inhibition of human carcinomas has previously been linked to vitamin D due to its effects on cancer cell proliferation, migration, angiogenesis, and apoptosis induction. The anticancer activity of vitamin D has been confirmed by several studies, which have shown that increased cancer incidence is associated with decreased vitamin D and that dietary supplementation of vitamin D slows down the growth of xenografted tumors in mice. Vitamin D inhibits the growth of cancer cells by the induction of apoptosis as well as by arresting the cells at the G0/G1 (or) G2/M phase of the cell cycle. Aim and Key Scientific Concepts of the Review: The purpose of this article is to thoroughly review the existing information and discuss and debate to conclude whether vitamin D could be used as an agent to prevent/treat cancers. The existing empirical data have demonstrated that vitamin D can also work in the absence of vitamin D receptors (VDRs), indicating the presence of multiple mechanisms of action for this sunshine vitamin. Polymorphism in the VDR is known to play a key role in tumor cell metastasis and drug resistance. Although there is evidence that vitamin D has both therapeutic and cancer-preventive properties, numerous uncertainties and concerns regarding its use in cancer treatment still exist. These include (a) increased calcium levels in individuals receiving therapeutic doses of vitamin D to suppress the growth of cancer cells; (b) hyperglycemia induction in certain vitamin D-treated study participants; (c) a dearth of evidence showing preventive or therapeutic benefits of cancer in clinical trials; (d) very weak support from proof-of-principle studies; and (e) the inability of vitamin D alone to treat advanced cancers. Addressing these concerns, more potent and less toxic vitamin D analogs have been created, and these are presently undergoing clinical trial evaluation. To provide key information regarding the functions of vitamin D and VDRs, this review provided details of significant advancements in the functional analysis of vitamin D and its analogs and VDR polymorphisms associated with cancers.

An infant developing hypercalcemia and hypophosphatemia due to the use of exclusively almond milk

OBJECTIVES

Plant-based milk alternatives are increasingly utilized in children with cow milk allergy, lactose intolerance, and personal preference. However, notable differences exist in mineral content between cow milk and plant-based alternatives. Almond milk, in particular, varies in mineral and caloric content across different brands. This case report highlights a toddler who developed hypercalcemia and hypophosphatemia attributed to almond milk consumption.

CASE PRESENTATION

A fourteen-month-old girl with a history of biliary atresia underwent liver transplant at seven months of age. She was exclusively consuming almond milk for two months prior to presentation. She was admitted to the hospital for severe hypercalcemia (14.6 mg/dL) and hypophosphatemia (1.6 mg/dL). She had elevated random urine calcium to creatinine ratio (2.56 mg/g) and low urine phosphorus to creatinine ratio (<0.44 mg/g) were noted. Parathyroid hormone (PTH) level was appropriately suppressed (<6 pg/mL), while 1,25 dihydroxyvitamin D level was slightly elevated at 88 pg/mL. Initial management included intravenous fluids, followed by a switch to a formula with higher phosphorus and lower calcium concentrations. The patient was discharged after six days with normalized calcium and phosphorus levels, which remained within the normal range.

CONCLUSIONS

Although plant-derived milk serves as a viable alternative to cow milk, careful consideration of mineral content, particularly in infants and toddlers, is imperative. Sole reliance on almond milk for nutritional needs in this population is not recommended. Caregivers should be informed about the potential risks associated with almond milk consumption in infants and toddlers.

1,25(OH)2 D3 inhibits Lewis lung cancer cell migration via NHE1-sensitive metabolic reprograming

High prevalence and metastasis rates are characteristics of lung cancer. Glycolysis provides energy for the development and metastasis of cancer cells. The 1,25-dihydroxy vitamin D3 (1,25(OH)2 D3 ) has been linked to reducing cancer risk and regulates various physiological functions. We hypothesized that 1,25(OH)2 D3 could be associated with the expression and activity of Na+ /H+ exchanger isoform 1 (NHE1) of Lewis lung cancer cells, thus regulating glycolysis as well as migration by actin reorganization. Followed by online public data analysis, Vitamin D3 receptor, the receptor of 1,25(OH)2 D3 has been proved to be abundant in lung cancers. We demonstrated that 1,25(OH)2 D3 treatment suppressed transcript levels, protein levels, and activity of NHE1 in LLC cells. Furthermore, 1,25(OH)2 D3 treatment resets the metabolic balance between glycolysis and OXPHOS, mainly including reducing glycolytic enzymes expression and lactate production. In vivo experiments showed the inhibition effects on tumor growth as well. Therefore, we concluded that 1,25(OH)2 D3 could amend the NHE1 function, which leads to metabolic reprogramming and cytoskeleton reconstruction, finally inhibits the cell migration.

Malignant Hypercalcemia Due to the Ectopic Production of Calcitriol by an Abdominal Liposarcoma

Hypercalcemia of malignancy (HM) is a common form of paraneoplastic syndrome associated with a poor prognosis of the disease. In solid tumors, HM occurs mainly due to the production of parathyroid hormone-related peptide (PTHrP). We present a case of a 60-year-old male with a 25 cm retroperitoneal liposarcoma diagnosed with severe hypercalcemia (16.8 mg/dL) by a preoperative blood sampling. Hypercalcemia workup showed suppressed parathyroid hormone (PTH), normal PTHrP, and high 1,25-dihydroxyvitamin D (1,25(OH)2D) serum levels. After surgery, hypercalcemia and calcitriol levels normalized. Immunohistochemical analysis of the tumor showed 1α-hydroxylase expression by tumor cells. To our knowledge, this is the first case of liposarcoma-associated hypercalcemia caused exclusively by the ectopic production of calcitriol. Despite being a rare cause of hypercalcemia, measuring 1,25(OH)2D should be considered in the workup of a patient with high serum calcium levels, suppressed PTH, and normal PTHrP.

Hypercalcemia: A Review

IMPORTANCE

Hypercalcemia affects approximately 1% of the worldwide population. Mild hypercalcemia, defined as total calcium of less than 12 mg/dL (<3 mmol/L) or ionized calcium of 5.6 to 8.0 mg/dL (1.4-2 mmol/L), is usually asymptomatic but may be associated with constitutional symptoms such as fatigue and constipation in approximately 20% of people. Hypercalcemia that is severe, defined as total calcium of 14 mg/dL or greater (>3.5 mmol/L) or ionized calcium of 10 mg/dL or greater (≥2.5 mmol/L) or that develops rapidly over days to weeks, can cause nausea, vomiting, dehydration, confusion, somnolence, and coma.

OBSERVATIONS

Approximately 90% of people with hypercalcemia have primary hyperparathyroidism (PHPT) or malignancy. Additional causes of hypercalcemia include granulomatous disease such as sarcoidosis, endocrinopathies such as thyroid disease, immobilization, genetic disorders, and medications such as thiazide diuretics and supplements such as calcium, vitamin D, or vitamin A. Hypercalcemia has been associated with sodium-glucose cotransporter 2 protein inhibitors, immune checkpoint inhibitors, denosumab discontinuation, SARS-CoV-2, ketogenic diets, and extreme exercise, but these account for less than 1% of causes. Serum intact parathyroid hormone (PTH), the most important initial test to evaluate hypercalcemia, distinguishes PTH-dependent from PTH-independent causes. In a patient with hypercalcemia, an elevated or normal PTH concentration is consistent with PHPT, while a suppressed PTH level (<20 pg/mL depending on assay) indicates another cause. Mild hypercalcemia usually does not need acute intervention. If due to PHPT, parathyroidectomy may be considered depending on age, serum calcium level, and kidney or skeletal involvement. In patients older than 50 years with serum calcium levels less than 1 mg above the upper normal limit and no evidence of skeletal or kidney disease, observation may be appropriate. Initial therapy of symptomatic or severe hypercalcemia consists of hydration and intravenous bisphosphonates, such as zoledronic acid or pamidronate. In patients with kidney failure, denosumab and dialysis may be indicated. Glucocorticoids may be used as primary treatment when hypercalcemia is due to excessive intestinal calcium absorption (vitamin D intoxication, granulomatous disorders, some lymphomas). Treatment reduces serum calcium and improves symptoms, at least transiently. The underlying cause of hypercalcemia should be identified and treated. The prognosis for asymptomatic PHPT is excellent with either medical or surgical management. Hypercalcemia of malignancy is associated with poor survival.

CONCLUSIONS AND RELEVANCE

Mild hypercalcemia is typically asymptomatic, while severe hypercalcemia is associated with nausea, vomiting, dehydration, confusion, somnolence, and coma. Asymptomatic hypercalcemia due to primary hyperparathyroidism is managed with parathyroidectomy or observation with monitoring, while severe hypercalcemia is typically treated with hydration and intravenous bisphosphonates.

What Lies behind Paraneoplastic Hypercalcemia Secondary to Well-Differentiated Neuroendocrine Neoplasms? A Systematic Review of the Literature

BACKGROUND

Neuroendocrine neoplasms (NEN) originate from neuroendocrine cells ubiquitously spread throughout the body. Hypercalcemia associated with cancer is the most common life-threatening metabolic disorder in patients with advanced stage cancer. Paraneoplastic hypercalcemia is more commonly associated with hematological malignancies, renal and breast carcinomas, and squamous cell carcinomas, but it has also been described in patients with well-differentiated NEN, where it often remains undiagnosed. Among its causes, systemic secretion of parathyroid hormone-related protein (PTHrP) and ectopic production of 1,25-dihydroxyvitamin D and parathyroid hormone (PTH) may be considered paraneoplastic causes of hypercalcemia. In order to clarify the diagnostic work up of paraneoplastic hypercalcemia in patients with NEN, we perform a systematic review, which is lacking in the literature.

METHODS

We performed a data search using MEDLINE and SCOPUS including papers from 1961 to 2021. We selected articles on paraneoplastic hypercalcemia associated with well-differentiated NEN.

RESULTS

The search led to the selection of 78 publications for a total of 114 patients. Pooled data showed that the most frequent primary tumor site associated with paraneoplastic hypercalcemia was pancreatic NEN, followed by Pheochromocytoma. In most cases, paraneoplastic hypercalcemia was caused by PTHrP production and secretion. In more than two thirds of cases, paraneoplastic hypercalcemia was present at the time of NEN diagnosis and, in metachronous cases, was related to local recurrence, distant metastasis development, or tumor progression. In most patients, a combination of therapeutic approaches was employed, and reduction of the tumor burden was essential to control the paraneoplastic syndrome.

DISCUSSION

The onset of hypercalcemia associated with cancer in patients with well-differentiated NEN represents a major clinical challenge. The complex clinical and therapeutical management of paraneoplastic hypercalcemia implies the need for a multidisciplinary approach, aimed at controlling the clinical syndrome and tumor growth.

Hypercalcemia Associated with the Ectopic Expression of 25-hydroxyvitamin D3-1α-hydroxylase in Diffuse Large B-cell Lymphoma

An 82-year-old man was transferred to our hospital due to impaired consciousness. His albumin-corrected calcium level was 14.2 mg/dL, intact parathyroid hormone (PTH) and PTH-related protein levels were reduced, and his 1,25-dihydroxyvitamin D [1,25 (OH) 2VitD] level was elevated at 71.5 pg/mL. Computed tomography revealed masses on the bilateral ribs. The mass on the rib was biopsied and diagnosed as diffuse large B-cell lymphoma (DLBCL). Immunostaining of the biopsy sample with the anti-CYP27B1 antibody revealed the ectopic expression of 1α-hydroxylase in the lesion. We herein report a rare case of hypercalcemia induced by the overproduction of 1,25 (OH) 2VitD in DLBCL ectopically expressing 1α-hydroxylase.

Hypercalcemia in non-Hodgkin's lymphoma due to cosecretion of PTHrP and 1,25-dihydroxyvitamin D

Hypercalcemia occurs in up to 30% of patients with malignancies and can be due to osteolysis by metastases, parathyroid hormone-related protein (PTHrP), excess 1,25-dihydroxyvitamin D (1,25(OH)₂D) production or, rarely, ectopic parathyroid hormone (PTH) secretion. Hypercalcemia in non-Hodgkin's lymphoma has been described with elevations in PTHrP or, more commonly, excess 1,25(OH)₂D production. We present the first case of a patient with new diagnosis of non-Hodgkin's lymphoma and severe hypercalcemia who was found to have concurrently elevated PTHrP and 1,25(OH)₂D. In human studies, PTHrP has shown limited ability to stimulate 1,25(OH)₂D production. To demonstrate that both PTHrP and 1,25(OH)₂D were of tumor origin in our patient, tissue from her tumor underwent histochemical staining, demonstrating expression of both PTHrP and CYP27B1, indicating the presence of 1,25(OH)₂D production in the tumor tissue. Our case illustrates the complexity of hypercalcemia in patients with underlying malignancy and highlights the importance of a thorough diagnostic workup for achievement of a successful therapeutic approach. In our patient, definitive chemotherapeutic treatment resulted in achievement and maintenance of normal calcium, PTHrP and 1,25(OH)₂D levels 18 months after initial diagnosis. Hypercalcemia occurs in up to 30% of malignancies and can be due to several mechanisms. We present the first case of cosecretion of parathyroid hormone related peptide (PTHrP) and 1,25-dihydroxyvitamin D (1,25(OH)₂D) in a patient with non-Hodgkin's lymphoma and demonstrate that both PTHrP and 1,25(OH)₂D were of tumor origin by immunohistochemical staining.

Multiple osteolytic primary peripheral T-cell bone lymphoma: the first case report

Peripheral T-cell lymphoma accounts for about 10% of all cases of non-Hodgkin’s lymphoma. However, less than 5% of patients with non-Hodgkin’s lymphoma present with hypercalcaemia as the initial symptom, and less than 1% present with primary bone lesions. We herein describe a 76-year-old Chinese man who was diagnosed with primary bone adult T-cell lymphoma with extensive osteolysis, including bone loss in the radius, as the initial manifestation. He had developed severe generalised bone pain and an inability to raise his arms. X-ray examination revealed osteolytic destruction of the forearm with loss of the radial diaphysis. The patient was diagnosed with peripheral T-cell lymphoma based on his immunohistochemical results. He began treatment with the CHOPE chemotherapy regimen, which resulted in significant improvement of his bone pain.

Vitamin D Toxicity

Fortification of food products with vitamin D was central to the eradication of rickets in the early parts of the 20th century in the United States. In the subsequent almost 100 years since, accumulating evidence has linked vitamin D deficiency to a variety of outcomes, and this has paralleled greater public interest and awareness of the health benefits of vitamin D. Supplements containing vitamin D are now widely available in both industrialized and developing countries, and many are in the form of unregulated formulations sold to the public with little guidance for safe administration. Together, this has contributed to a transition whereby a dramatic global increase in cases of vitamin D toxicity has been reported. Clinicians are now faced with the challenge of managing this condition that can present on a spectrum from asymptomatic to acute life-threatening complications. This article considers contemporary data on vitamin D toxicity, and diagnostic and management strategies relevant to clinical practice.

Primary Colonic Lymphoma With Paraneoplastic Hypercalcemia

Primary colonic lymphoma is a rare tumor accounting for 0.1%–0.5% of all colorectal malignancies. We describe a 63-year-old man whose initial presentation was altered mental status due to hypercalcemia. Physical examination revealed a hard, right-sided abdominal mass. Abdominal computed tomography showed a mass in the ascending colon, which on further evaluation with colonoscopy and biopsy was diagnosed as diffuse large B-cell lymphoma. A diagnosis of primary colonic lymphoma was made based on the Dawson criteria, after ruling out any extracolonic involvement. Workup for hypercalcemia showed elevated calcitriol levels, which is a paraneoplastic manifestation of the lymphoma.

Sequential Complications of Hypercalcemia, Necrotizing Granulomatous Vasculitis, and Aplastic Anemia Occurring in One Patient with Angioimmunoblastic T-cell Lymphoma

In this case report of a patient with angioimmunoblastic T-cell lymphoma (AITL), we describe the occurrence of three sequential complications that have been reported uncommonly in this disease subtype. Firstly, the patient developed hypercalcemia due to elevated 1,25-didydroxyvitamin D. Although hypercalcemia in AITL is not rare (1-2% incidence), this case was unusual in that the complication developed when disease appeared stable and symptomatically, he was doing well otherwise. Hypercalcemia surprisingly resolved a few months later at a time when his disease appeared to be progressing. A year later, the patient presented with digital ischemia necessitating partial amputation of a finger. Pathological exam revealed granulomatous vasculitis of small and medium arterioles with infiltrating malignant T lymphocytes. Although skin manifestations are common in AITL, necrotizing granulomatous vasculitis with accompanying tumor cells leading to severe digital ischemia appears rare. Subsequently the patient developed profound pancytopenia with bone marrow confirming severe aplastic anemia. To our knowledge only one other case of aplastic anemia has been reported in a patient with AITL. We discuss the diagnostic and management considerations involved in this patient care and review similar reported cases.

Immunologic Effects of Vitamin D on Human Health and Disease

Vitamin D is responsible for regulation of calcium and phosphate metabolism and maintaining a healthy mineralized skeleton. It is also known as an immunomodulatory hormone. Experimental studies have shown that 1,25-dihydroxyvitamin D, the active form of vitamin D, exerts immunologic activities on multiple components of the innate and adaptive immune system as well as endothelial membrane stability. Association between low levels of serum 25-hydroxyvitamin D and increased risk of developing several immune-related diseases and disorders, including psoriasis, type 1 diabetes, multiple sclerosis, rheumatoid arthritis, tuberculosis, sepsis, respiratory infection, and COVID-19, has been observed. Accordingly, a number of clinical trials aiming to determine the efficacy of administration of vitamin D and its metabolites for treatment of these diseases have been conducted with variable outcomes. Interestingly, recent evidence suggests that some individuals might benefit from vitamin D more or less than others as high inter-individual difference in broad gene expression in human peripheral blood mononuclear cells in response to vitamin D supplementation has been observed. Although it is still debatable what level of serum 25-hydroxyvitamin D is optimal, it is advisable to increase vitamin D intake and have sensible sunlight exposure to maintain serum 25-hydroxyvitamin D at least 30 ng/mL (75 nmol/L), and preferably at 40-60 ng/mL (100-150 nmol/L) to achieve the optimal overall health benefits of vitamin D.

Calcitriol Elevation Is Associated with a Higher Risk of Refractory Hypercalcemia of Malignancy in Solid Tumors

BACKGROUND

Hypercalcemia of malignancy (HCM) is a common complication of advanced cancer. PTH-independent HCM may be mediated through different mechanisms: (1) humoral HCM, caused by the secretion of PTH-related peptide (PTHrP), (2) local osteolysis resulting from metastatic lesions, and (3) calcitriol-mediated hypercalcemia. Calcitriol-mediated HCM in patients with nonlymphomatous solid tumors is thought to be rare.

METHODS

We performed a retrospective chart review from 2008 to 2017 to characterize further patients at our institution with solid tumors who had HCM with concomitant elevations in calcitriol. Patients with PTH-dependent hypercalcemia and patients with evidence of granulomatous disease were excluded, as were patients with hematologic malignancies. We hypothesized that patients with HCM and elevated calcitriol levels would respond less favorably to treatment with antiresorptive therapy compared with patients with HCM but without calcitriol elevation. We also aimed to assess mortality and determine if PTHrP and phosphorus levels correlate with calcitriol because both factors may alter calcitriol levels.

RESULTS

Of 101 eligible patients, calcitriol was elevated in 45 (45%). PTHrP was elevated in 76% of patients with elevated calcitriol compared with 52% of patients without calcitriol elevation. The mean PTHrP value did not differ between patients with HCM and elevated calcitriol (36.3 ± 22 pg/mL) and those without calcitriol elevation (37.4 ± 19 pg/mL). Those with elevated calcitriol levels generally did not respond completely to antiresorptive treatment (80% incomplete response rate), whereas most patients without an elevation in calcitriol responded well to antiresorptive treatment (78% response rate: P < .001). There was no significant difference in the percentage of patients with metastatic bone disease among the 2 groups (49% vs. 55%, respectively). There was no difference in mortality between the 2 groups (P = .14). A weak but significant negative correlation was found between phosphorus and calcitriol (Pearson r = -0.261, P = .016). This correlation was only significant in patients without calcitriol elevation (Pearson r = -0.4, P = .0082). Also, a significant negative correlation was found between PTHrP and phosphorus, again only in patients without calcitriol elevation.

DISCUSSION

In the setting of HCM, patients with calcitriol elevation are much less likely to respond to antiresorptive therapy than patients without calcitriol elevation. Because calcitriol elevation did not appear to be correlated with hypophosphatemia or elevated PTHrP, it would appear that calcitriol production under these conditions is autonomous, and not subject to normal physiological controls. These observations indicate that calcitriol elevations in patients with HCM have clinical significance.

Primary hyperparathyroidism associated with non-Hodgkin lymphoma: a case report and literature review

Primary hyperparathyroidism is the third most common endocrine disease, while primary hyperparathyroidism associated with non-Hodgkin lymphoma(NHL) is extremely rare. We report a case of primary hyperparathyroidism associated with NHL. The first symptom of this patient was hypercalcemia. Hypercalcemia is the primary first clinical manifestation of primary hyperparathyroidism, while NHL may also be diagnosed by hypercalcemia. Clinically, patients with hypercalcemia as the first symptom should be alert to the coexistence of their two diseases. As primary hyperparathyroidism and NHL occur simultaneously, the relationship between the two diseases requires further study. A review of the literature regarding primary hyperparathyroidism associated with NHL was performed, focusing on clinical presentation, diagnosis, treatment, prognosis, and the connection.

Elevated Levels of 1,25-Dihydroxyvitamin D in Plasma as a Missing Risk Factor for Celiac Disease

The prevalence of celiac disease (CD) has increased significantly in some developed countries in recent decades. Potential risk factors that have been considered in the literature do not appear to provide a convincing explanation for this increase. This has led some researchers to hypothesize that there is a "missing environmental factor" that increases the risk of CD. Based on evidence from the literature, the author proposes that elevation in plasma levels of 1,25-dihydroxyvitamin D [1,25(OH)₂D] is a missing risk factor for CD, and relatedly that significant oral vitamin D exposure is a "missing environmental factor" for CD. First, elevated plasma levels of 1,25(OH)₂D are common in CD, especially in the newly diagnosed. Second, nine distinct conditions that increase plasma levels of 1,25(OH)₂D are either associated with CD or have indications of such an association in the literature. Third, a retrospective study shows that sustained oral vitamin D supplementation in infancy is associated with increased CD risk, and other studies on comorbid conditions support this association. Fourth, large doses of oral vitamin D upregulate many of the same cytokines, chemokines, and toll-like receptors that are upregulated in CD. Fifth, epidemiological evidence, such as the timing of the inception of a CD "epidemic" in Sweden, the increased prevalence of CD in Finland and the United States in recent decades, the unusually low prevalence of CD in Germany, and the differential in prevalence between Finnish Karelians and Russian Karelians, may all be explained by oral vitamin D exposure increasing CD risk. The same is true of some seemingly contradictory results in the literature on the effects of breastfeeding on CD risk. If future research validates this hypothesis, adjustments to oral vitamin D consumption among those who have genetic susceptibility may decrease the risk of CD in these individuals.

Hypercalcemia is associated with a poor prognosis in lymphoma a retrospective monocentric matched-control study and extensive review of published reported cases

The prognostic significance of hypercalcemia in lymphoma has only been studied on small series to date. We conducted a retrospective, monocentric, matched-control study that aimed to compare the outcome of patients diagnosed with any histological subtype of lymphoma associated with hypercalcemia, at diagnosis or relapse, with a group of controls matched for histological and prognostic factors. Sixty-two and 118 comparable patients treated between 2000 and 2016 were included in hypercalcemia and control cohorts, respectively. Hypercalcemia was found mainly at diagnosis (71%) in higher-risk patients (prognosis scores ≥ 3, 76%) and those with diffuse large B cell lymphoma (67.7%), stage III/IV disease (91.9%), and elevated LDH (90.3%). Two-year progression-free survival (PFS) was shorter in the hypercalcemia than control cohort [30.1% (95% confidence interval (95% CI) 18.3-41.9) vs 63.9% (95% CI 5.1-72.7), p < 0.001]. Two-year overall survival (OS) was 40.6% (95% CI 28.1-53.1) and 77.7% (95% CI 70.1-85.3) in the hypercalcemia and control cohorts, respectively (p < 0.001). Hypercalcemia was independently associated with poor PFS [HR = 2.5 (95% CI 1.4-3.5)] and OS [HR = 4.7 (95% CI 2.8-7.8)] in multivariate analysis. Among the 40 patients who received autologous stem cell transplantation (ASCT), hypercalcemia was still associated with shorter OS [2-year OS: 65% (95% CI 40.1-89.9) vs 88.0 (95% CI 75.3-100), p = 0.04]. Hypercalcemia may be associated with chemo-resistance, given its impact on PFS and OS. Hence, these data suggest that alternate strategies for lymphoma patients with hypercalcemia should be developed.

Methotrexate-induced iatrogenic immunodeficiency-associated lymphoproliferative disorder causing hypercalcaemia

Hypercalcaemia is a rare but potentially life-threatening consequence of malignancies. Solid cancers, such as lymphomas, increase serum calcium primarily through parathyroid hormone-related protein or ectopic production of 1alpha-hydroxylase. We present a case of 56-year-old woman with Sjogren's syndrome and psoriasis in the setting of chronic methotrexate (MTX) use who developed worsening hypercalcaemia and symptoms suggestive of lymphoma. Pathology results diagnosed her with MTX-induced iatrogenic immunodeficiency-associated lymphoproliferative disorder (LPD). This case reminds clinicians that chronic MTX use is associated with LPDs and can ultimately lead to hypercalcaemia. The patient's MTX and other immunosuppressive medications were stopped, and her calcium corrected with fluids and calcitonin. At her 8-month follow-up postdischarge, the patient was asymptomatic with normal laboratory results and in partial clinical remission.

No Stones, Some Groans, and Psychiatric Overtones with "Non-specific" Splenomegaly

Hypercalcemia is a potentially life-threatening electrolyte imbalance that is commonly caused by hyperparathyroidism, supplement or medication use, and/or malignancy. Splenomegaly is commonly a non-specific finding, but in the setting of hypercalcemia, may provide diagnostic insight into the underlying pathology and warrant further evaluation. A 70-year-old man presented from his outpatient provider with serum calcium > 15 mg/dL with complaints of one-month fatigue, weakness, poor oral intake, 10 lbs. unintentional weight loss, and periodic confusion noted by his wife. He received an extensive inpatient workup which was non-diagnostic. Splenomegaly was observed on radiographic imaging and reported as "nonspecific". Following discharge, denosumab was required to manage the hypercalcemia. Eventually, a diagnosis of primary splenic lymphoma was made months later. Laparoscopic splenectomy was planned but was advanced to an open laparotomy intraoperatively due to the rapid growth of the neoplasm. Early and close investigation of the spleen is warranted when splenomegaly presents in the setting of hypercalcemia and, as in this case, may prevent significant therapeutic burden.

Anaplastic large cell lymphoma, with 1,25(OH)2D3-mediated hypercalcemia: A case report

Hypercalcemia due to malignant tumors including malignant lymphomas is relatively common. Among cancer patients with hypercalcemia, humoral hypercalcemia of malignancy is the most common and accounts for about 80% of all cases with hypercalcemia. 1,25-dihydroxyvitamin D_³(1,25(OH)_²D_³)-mediated hypercalcemia is relatively rare. Although malignant lymphoma has been also reported to cause 1,25(OH)_²D_³-mediated hypercalcemia, it is not known whether there is any association between 1,25(OH)_²D_³-mediated hypercalcemia and any specific histological type of malignant lymphoma. We herein report a case of an anaplastic large cell lymphoma (ALCL), anaplastic lymphoma kinase (ALK) -negative with 1,25(OH)_²D_³-mediated hypercalcemia, which has never been previously reported. An 80-year-old Japanese man was admitted to our department due to acute exacerbation of hypercalcemia. He was diagnosed with ALCL, ALK-negative. Serum 1,25(OH)_²D_³ level was high and seemed to be associated with the lymphoma because the serum calcium and 1,25(OH)_²D_³ levels improved in response to chemotherapy. Histological findings showed that many CD68 positive macrophages were observed in the microenvironment of tumor cells. Lymphoma cells or tumor microenvironmental cells may produce 1,25(OH)_²D_³ because several previous reports showed the source of 1,25(OH)_²D_³ can be either lymphoma or tumor microenvironmental cells. Moreover, because 1,25(OH)_²D_³-mediated hypercalcemia has been reported regardless of the specific histological type of lymphoma, tumor microenvironmental cells may be involved in this condition. However, we could not identify the source of 1,25(OH)_²D_³ in this case. The association between 1,25(OH)_²D_³ production and prognosis in malignant lymphomas is yet unknown; further studies are needed to elucidate the clinical characteristics of malignant lymphoma with 1,25(OH)_²D_³-mediated hypercalcemia.

Hypercalcemia and cancer: Differential diagnosis and treatment

Incidentally detected hypercalcemia usually presents in an indolent manner and is most likely caused by primary hyperparathyroidism. In contrast, hypercalcemia in the patient with a history of cancer presents in a wide range of clinical settings and may be severe enough to warrant hospitalization. This form of hypercalcemia is usually secondary to hypercalcemia of malignancy and can be fatal. Hypercalcemia of malignancy is most commonly mediated by tumoral production of parathyroid hormone-related protein or by cytokines activating osteoclast degradation of bone. The initial workup, differential diagnoses, confirmatory laboratory testing, imaging, and medical and surgical management of hypercalcemia are described in the patient with cancer.

Hypercalcemia as a rare presentation of angioimmunoblastic T cell lymphoma: a case report

Background

Angioimmunoblastic T cell lymphoma is a rare malignancy, accounting for only 2% of all non-Hodgkin lymphomas, first described in the 1970s and subsequently accepted as a distinct entity in the current World Health Organization classification. Due to the paucity of this disease, there is still no identifiable etiology, no consistent risk factors, and the pathogenesis remains unclear.

Case presentation

An 83-year-old Caucasian man presented to an emergency department with palpitations and was found to have atrial fibrillation. During his hospitalization, he was found to have asymptomatic hypercalcemia with corrected calcium of 11.7. Ten days later while in rehabilitation, he started complaining of progressive fatigue and altered mental status was noted. He was found to have a calcium level of 15.5 and was admitted to the intensive care unit for management and further workup. He was found at that time to have, parathyroid hormone: < 1; 25 hydroxyvitamin D: 74; 1,25 dihydroxyvitamin D: 85.4; angiotensin-converting enzyme: 7; parathyroid hormone-related protein: < 2; and multiple myeloma workup was negative. Computed tomography of his chest and abdomen showed extensive retroperitoneal, pelvic, and mesenteric lymphadenopathy in addition to findings suggestive of peritoneal carcinomatosis. A right axillary lymph node biopsy showed immunohistochemical parameters consistent with angioimmunoblastic T cell lymphoma. After a lengthy discussion with his family, it was decided that no further treatment would be pursued. He had an aggressive course at the hospital during which he developed pleural effusions, ascites, and diffuse petechiae within 2 weeks; these were complications from his malignancy. Considering the poor outcomes of his aggressive disease, he decided to enroll in an out-patient hospice. He died within a few months as a result of cardiorespiratory arrest.

Conclusions

This case illustrates a rare presentation of an extremely rare disease; that is, hypercalcemia in a patient who was later found to have angioimmunoblastic T cell lymphoma. Diagnosing angioimmunoblastic T cell lymphoma might be the most challenging part due to the wide array of clinical presentations, of which hypercalcemia accounts for only 1%. As seen in this case, most patients present in advanced stages of the disease with poor prognosis.

Mechanisms of Hypercalcemia in Non-Hodgkin Lymphoma and Associated Outcomes: A Retrospective Review

INTRODUCTION

The etiology of hypercalcemia in non-Hodgkin lymphoma (NHL) has been most often attributed to either elevated serum levels of 1,25-dihydroxycholecalciferol (calcitriol) or parathyroid-related protein (PTHrP). In a single-center retrospective review, we evaluated the incidence of, and outcomes associated with, hypercalcemia in NHL.

PATIENTS AND METHODS

The medical records of patients with a histologically confirmed diagnosis of NHL and ≥ 1 episode of hypercalcemia were evaluated for demographic and lymphoma-specific factors, including the response to therapy and overall survival.

RESULTS

Fifty-four patients with NHL met the inclusion criteria. Most patients (57.4%) had diffuse large B-cell lymphoma, of which, 70% were the nongerminal center subtype. Approximately one half (42.6%) of the included patients had undergone serologic investigation into the etiology of hypercalcemia; however, only 17 patients (31.5%) had both a serum PTHrP and a calcitriol level properly collected. Of the 17 cases for which both a serum calcitriol and a PTHrP were collected, most (61.1%) were found to have neither an elevation of serum calcitriol nor an elevation of PTHrP. The degree of calcitriol elevation correlated with worse progression-free survival (P = .04) but not overall survival.

CONCLUSION

The major mechanism by which NHL patients develop hypercalcemia is not mediated by calcitriol or PTHrP. Hypercalcemia is most prevalent in patients with diffuse large B-cell lymphoma of the nongerminal cell subtype. Patients with calcitriol-mediated hypercalcemia showed a trend toward worse outcomes, suggesting that calcitriol might be a marker of high-grade lymphoma, transformation to such, or a surrogate for more advanced disease.

Vitamin D receptor and progesterone receptor protein and gene expression in papillary thyroid carcinomas: associations with histological features

PURPOSE

Vitamin D receptor (VDR) and progesterone receptor (PR) expression has been described in papillary thyroid carcinoma (PTC) but data regarding association with tumor histological characteristics and localization of the protein expression are scarce.

MATERIALS AND METHODS

Formalin-fixed, paraffin-embedded specimens from 45 patients with PTC (cases) were retrieved and tumor histological data were recorded. We analyzed gene and protein expression of VDR and PR and gene expression of vitamin D-inactivating 24-hyroxylase (CYP24A1) and the activating 1-alpha-hydroxylase (CYP27B1) enzymes in follicular cancer cells and the adjacent non-neoplastic thyroid tissue (NNTT).

RESULTS

VDR mRNA and protein expression was higher in PTC compared with NNTT (p < 0.05). The protein was globally localized in the cytoplasm and cell membranes of the neoplastic cells in all cases, with differences in intensity. Cytoplasmic positivity was stronger in the majority of cases. Membranous positivity was also evident in cases, whereas in NNTT was generally weak and in a low percentage of the cells. Expression of CYP 24A1, but not CYP27B1, was increased in approximately all PTC specimens and was associated with lymph node metastasis and extrathyroidal extension. PR mRNA was increased in 34% and protein expression was present in 57% of cases, and none of NNTT. PR, but not VDR, mRNA expression was significantly associated with the tumor size (r = 0.645, p = 0.007).

CONCLUSIONS

We provide evidence for the expression pattern of VDR, PR and CYP24A1 in the progression of PTC. Rapid anti-tumor responses of vitamin D in PTC may be blocked due to inactivation of local vitamin D metabolism.

Hypercalcemia in Lung Cancer due to Simultaneously Elevated PTHrP and Ectopic Calcitriol Production: First Case Report

Calcitriol-mediated hypercalcemia has been reported in malignant lymphomas and granulomatous diseases but not in lung carcinoma. We describe a patient with squamous cell lung carcinoma with hypercalcemia and elevated calcitriol levels. A 60-year-old Caucasian male patient with stage IIIB squamous cell lung cancer developed hypercalcemia at 14.8 mg/dL two years after receiving chemotherapy and radiotherapy where labs showed a serum intact PTH: 7 pg/mL, PTHrP: 30 pmol/L, 1,25-hydroxyvitamin D (calcitriol): 76 pg/mL, and 25-hydroxyvitamin D levels: <4 ng/mL. Calcitriol levels were elevated despite undetectable 25-hydroxyvitamin D levels. There are no reported lung cancer cases with elevated calcitriol as an etiology of hypercalcemia. We believe that the elevated calcitriol levels in this case were due to a PTHrP-independent mechanism, possibly from either ectopic production of calcitriol in tumor cells or from increased activity of 1-alpha hydroxylase in the same cells. The patient died before the effects of prednisone therapy could be assessed. Studies are needed to investigate the cellular source of calcitriol and its role in hypercalcemia in patients with lung cancer.

Animal Models of Cancer-Associated Hypercalcemia

Cancer-associated hypercalcemia (CAH) is a frequently-occurring paraneoplastic syndrome that contributes to substantial patient morbidity and occurs in both humans and animals. Patients with CAH are often characterized by markedly elevated serum calcium concentrations that result in a range of clinical symptoms involving the nervous, gastrointestinal and urinary systems. CAH is caused by two principle mechanisms; humorally-mediated and/or through local osteolytic bone metastasis resulting in excessive calcium release from resorbed bone. Humoral hypercalcemia of malignancy (HHM) is the most common mechanism and is due to the production and release of tumor-associated cytokines and humoral factors, such as parathyroid hormone-related protein (PTHrP), that act at distant sites to increase serum calcium concentrations. Local osteolytic hypercalcemia (LOH) occurs when primary or metastatic bone tumors act locally by releasing factors that stimulate osteoclast activity and bone resorption. LOH is a less frequent cause of CAH and in some cases can induce hypercalcemia in concert with HHM. Rarely, ectopic production of parathyroid hormone has been described. PTHrP-mediated hypercalcemia is the most common mechanism of CAH in human and canine malignancies and is recognized in other domestic species. Spontaneous and experimentally-induced animal models have been developed to study the mechanisms of CAH. These models have been essential for the evaluation of novel approaches and adjuvant therapies to manage CAH. This review will highlight the comparative aspects of CAH in humans and animals with a discussion of the available animal models used to study the pathogenesis of this important clinical syndrome.

Hypercalcemia of Malignancy in Thymic Carcinoma: Evolving Mechanisms of Hypercalcemia and Targeted Therapies

Here we describe, to our knowledge, the first case where an evolution of mechanisms responsible for hypercalcemia occurred in undifferentiated thymic carcinoma and discuss specific management strategies for hypercalcemia of malignancy (HCM). Case Description. We report a 26-year-old male with newly diagnosed undifferentiated thymic carcinoma associated with HCM. Osteolytic metastasis-related hypercalcemia was presumed to be the etiology of hypercalcemia that responded to intravenous hydration and bisphosphonate therapy. Subsequently, refractory hypercalcemia persisted despite the administration of bisphosphonates and denosumab indicative of refractory hypercalcemia. Elevated 1,25-dihydroxyvitamin D was noted from the second admission with hypercalcemia responding to glucocorticoid administration. A subsequent PTHrP was also elevated, further supporting multiple mechanistic evolution of HCM. The different mechanisms of HCM are summarized with the role of tailoring therapies based on the particular mechanism underlying hypercalcemia discussed. Conclusion. Our case illustrates the importance of a comprehensive initial evaluation and reevaluation of all identifiable mechanisms of HCM, especially in the setting of recurrent and refractory hypercalcemia. Knowledge of the known and possible evolution of the underlying mechanisms for HCM is important for application of specific therapies that target those mechanisms. Specific targeting therapies to the underlying mechanisms for HCM could positively affect patient outcomes.

Vitamin D-mediated hypercalcemia in multicentric Castleman's disease

Multicentric Castleman's disease (MCD) is a rare lymphoproliferative disorder, which represents various symptoms caused by the hyperproduction of interleukin-6 (IL-6). However, case studies of MCD accompanied by hypercalcemia have rarely been reported thus far. A 78-year-old male had generalized fatigue, and his laboratory data revealed elevated serum calcium (Ca) and 1,25-dihydroxyvitamin D [1,25(OH)₂D] levels (11.5 mg/dl and 80 pg/ml, respectively), while the serum intact parathyroid hormone level was low (4 pg/ml). Computed tomography showed multicentric lymphadenopathy. The serum IL-6 level was elevated (20.7 pg/ml), and pathological examination of a supraclavicular lymph node specimen led us to diagnose MCD. Moreover, immunostaining analysis showed that vitamin D-activating enzyme 25-hydroxyvitamin D 1-alpha-hydroxylase was expressed in lymph node macrophages. Prednisolone treatment improved the hypercalcemia and decreased the levels of 1,25(OH)₂D and IL-6. We first reported a case of vitamin D-mediated hypercalcemia in MCD.

Hypercalcemia due to Primary Hepatic Lymphoma

A 65-year-old female with a history of mixed connective tissue disease and pulmonary fibrosis on azathioprine, hydroxychloroquine, and prednisone (osteoporosis on teriparatide) presented with a 1-month history of hypercalcemia. After discontinuation of teriparatide, the patient's hypercalcemia persisted. Further evaluation revealed primary hepatic lymphoma as the source of her hypercalcemia.

Effects of High-Dose Vitamin D2 Versus D3 on Total and Free 25-Hydroxyvitamin D and Markers of Calcium Balance

CONTEXT

Controversy persists over: 1) how best to restore low serum 25-hydroxyvitamin D (25D) levels (vitamin D2 [D2] vs vitamin D3 [D3]); 2) how best to define vitamin D status (total [protein-bound + free] vs free 25D); and 3) how best to assess the bioactivity of free 25D.

OBJECTIVE

To assess: 1) the effects of D2 vs D3 on serum total and free 25D; and 2) whether change in intact PTH (iPTH) is more strongly associated with change in total vs free 25D.

DESIGN

Participants previously enrolled in a D2 vs D3 trial were matched for age, body mass index, and race/ethnicity. Participants received 50 000 IU of D2 or D3 twice weekly for 5 weeks, followed by a 5-week equilibration period. Biochemical assessment was performed at baseline and at 10 weeks.

SETTING AND PARTICIPANTS

Thirty-eight adults (19 D2 and 19 D3) ≥18 years of age with baseline 25D levels <30 ng/mL were recruited from an academic ambulatory osteoporosis clinic.

OUTCOME MEASURES

Serum measures were total 25D, free 25D (directly measured), 1,25-dihydroxyvitamin D, calcium, and iPTH. Urine measure was fasting calcium:creatinine ratio.

RESULTS

Baseline total (22.2 ± 3.3 vs 23.3 ± 7.2 ng/mL; P = .5) and free (5.4 ± 0.8 vs 5.3 ± 1.7 pg/mL; P = .8) 25D levels were similar between D2 and D3 groups. Increases in total (+27.6 vs +12.2 ng/mL; P = .001) and free (+3.6 vs +6.2 pg/mL; P = .02) 25D levels were greater with D3 vs D2. Percentage change in iPTH was significantly associated with change in free (but not total) 25D, without and with adjustment for supplementation regimen, change in 1,25-dihydroxyvitamin D, and change in calcium.

CONCLUSIONS

D3 increased total and free 25D levels to a greater extent than D2. Free 25D may be superior to total 25D as a marker of vitamin D bioactivity.

Hypercalcemia of malignancy and new treatment options

Hypercalcemia of malignancy affects up to one in five cancer patients during the course of their disease. It is associated with both liquid malignancies, commonly multiple myeloma, leukemia, and non-Hodgkins lymphoma and solid cancers, particularly breast and renal carcinomas as well as squamous cell carcinomas of any organ. The clinical manifestations of hypercalcemia are generally constitutional in nature and not specific to the inciting malignancy. Such physical manifestations can range from malaise to lethargy and confusion. Constipation and anorexia are common. Acute kidney injury is likely the most frequently encountered manifestation of end organ damage. Symptomatology is closely linked to both the absolute elevation of serum calcium levels and the rapidity of calcium rise. The majority of cases are humoral in etiology and related to parathyroid hormone-related protein (PTHrP). Approximately 20% of cases are the result of direct bone metastasis with extra-renal 1,25-dihydroxyvitamin D (calcitriol) and ectopic parathyroid hormone production likely accounting for less than 1% of cases. The diagnosis of hypercalcemia of malignancy is confirmed either by an elevated PTHrP or by an evidence of bone metastasis in the appropriate clinical setting. Treatment is predicated on the patient’s symptoms and absolute serum calcium level. Interventions are aimed at lowering the serum calcium concentration by inhibiting bone resorption and increasing urinary calcium excretion, the former accomplished via bisphosphonate therapy and the latter with aggressive hydration. Novel therapies for refractory disease include denosumab, a monoclonal antibody against the receptor activator of nuclear factor κB ligand, and the calcimimetic cinacalcet. Finally, anti-PTHrP antibodies have been successfully deployed in animal models of disease. Despite the efficacy of the above therapies, hypercalcemia of malignancy portends an ominous prognosis, indicating advanced and often refractory cancer with survival on the order of months.

Regulation of the voltage gated K channel Kv1.3 by recombinant human klotho protein

BACKGROUND/AIMS

Klotho, a protein mainly produced in the kidney and released into circulating blood, contributes to the negative regulation of 1,25(OH)2D3 formation and is thus a powerful regulator of mineral metabolism. As β-glucuronidase, alpha Klotho protein further regulates the stability of several carriers and channels in the plasma membrane and thus regulates channel and transporter activity. Accordingly, alpha Klotho protein participates in the regulation of diverse functions seemingly unrelated to mineral metabolism including lymphocyte function. The present study explored the impact of alpha Klotho protein on the voltage gated K+ channel Kv1.3.

METHODS

cRNA encoding Kv1.3 (KCNA3) was injected into Xenopus oocytes and depolarization induced outward current in Kv1.3 expressing Xenopus oocytes determined utilizing dual electrode voltage clamp. Experiments were performed without or with prior treatment with recombinant human Klotho protein (50 ng/ml, 24 hours) in the absence or presence of a β-glucuronidase inhibitor D-saccharic acid-1,4-lactone (DSAL, 10 µM). Moreover, the voltage gated K+ current was determined in Jcam lymphoma cells by whole cell patch clamp following 24 hours incubation without or with recombinant human Klotho protein (50 ng/ml, 24 hours). Kv1.3 protein abundance in Jcam cells was determined utilising fluorescent antibodies in flow cytometry.

RESULTS

In Kv1.3 expressing Xenopus oocytes the Kv1.3 currents and the protein abundance of Kv1.3 were both significantly enhanced after treatment with recombinant human Klotho protein (50 ng/ml, 24 hours), an effect reversed by presence of DSAL. Moreover, treatment with recombinant human Klotho protein increased Kv currents and Kv1.3 protein abundance in Jcam cells.

CONCLUSION

Alpha Klotho protein enhances Kv1.3 channel abundance and Kv1.3 currents in the plasma membrane, an effect depending on its β-glucuronidase activity.

Peripheral T-cell lymphoma with hypercalcemic crisis as a primary symptom accompanied by polymyositis: A case report and review of the literature

The present study reports the case of a 61-year-old male with polymyositis who presented with exacerbated weakness in the lower limbs and a recurrent fever that had persisted for one month. Positron emission tomography/computed tomography scans revealed multiple regions of elevated fluorodeoxyglucose metabolism in the lymph nodes, lungs, liver, spleen and bones. While symptoms of nonchalance and confusion were identified on admission, the patient’s serum calcium level was high at 3.87 mmol/l, so a hypercalcemic crisis was confirmed. A biopsy of the right lingual lymph node revealed peripheral T-cell lymphoma, not otherwise specified. The serum calcium level was restored to within the normal range following emergency measures, such as saline rehydration, diuretics, calcitonin and glucocorticoids, and partial remission was achieved following two courses of chemotherapy. The study may improve our present understanding of the diagnosis and treatment of cancer-associated myositis (CAM) and malignancy-associated hypercalcemia.

Hypercalcemia in tumor lysis syndrome

Tumor lysis syndrome (TLS) is characterized by hyperkalemia, hyperuricemia, hypocalcemia and hyperphosphatemia. This report describes a case of hypercalcemia in TLS in a patient with diffuse large B cell lymphoma.

Unusual manifestation of intravascular large B-cell lymphoma: severe hypercalcemia with parathyroid hormone-related protein

Intravascular large B-cell lymphoma (IVLBCL) is a rare subtype of non-Hodgkin lymphoma. It usually presents with nonspecific symptoms, such as fever, rather than with overt lymphadenopathy. Reports of hypercalcemia, as the initial presentation of IVLBCL, are limited in the literature, despite it being a well-known complication of various solid cancers. We present a 68-year-old male with severe hypercalcemia and increased levels of serum parathyroid hormone-related protein. He was diagnosed with IVLBCL, involving the bone marrow and spleen, and was successfully treated with rituximab-containing chemotherapy. A few previous case reports have shown hypercalcemia in patients with IVLBCL. Much like our case, previous cases with hypercalcemia had advanced diseases, including bone marrow invasion. Although it was an extremely rare manifestation of IVLBCL, we suggest that IVLBCL should be a part of the differential diagnosis in patients with unexplained hypercalcemia. Therefore, an active work-up might be recommended, including positron emission tomography/ computed tomography scan and bone marrow examination, which may be useful for early diagnosis.

1,25-dihydroxyvitamin D and PTHrP mediated malignant hypercalcemia in a seminoma

BACKGROUND

Seminomas have been rarely associated with malignant hypercalcemia. The responsible mechanism of hypercalcemia in this setting has been described to be secondary to 1,25-dihydroxyvitamin D secretion. The relationship with PTHrP has not been determined or studied.The aim of this study is to describe and discuss the case and the pathophysiological mechanisms involved in a malignant hypercalcemia mediated by 1,25-dihydroxyvitamin D and PTHrP cosecretion in a patient with seminoma.

CASE PRESENTATION

A 35-year-old man was consulted for assessment and management of severe hypercalcemia related to an abdominal mass. Nausea, polyuria, polydipsia, lethargy and confusion led him to the emergency department. An abdominal and pelvic enhanced CT confirmed a calcified pelvic mass, along with multiple retroperitoneal lymphadenopathy. Chest x-ray revealed "cannon ball" pulmonary metastases. The histopathology result was consistent with a seminoma. Serum calcium was 14.7 mg/dl, PTH was undetectable, 25-dihydroxyvitamin D was within normal values and PTHrP and 1,25-dihydroxyvitamin were elevated (35.0 pg/ml, and 212 pg/ml, respectively). After the first cycle of chemotherapy with bleomycin, etoposide and cisplatin, normocalcemia was restored. Both PTHrP and 1,25-dihydroxyvitamin D, dropped dramatically to 9.0 pg/ml and 8.0 pg/ml, respectively.

CONCLUSION

The association of seminoma and malignant hypercalcemia is extremely rare. We describe a case of a patient with a seminoma and malignant hypercalcemia related to paraneoplastic cosecretion of 1,25-dihydroxyvitamin D and PTHrP. After successful chemotherapy, calcium, PTHrP and 1,25-Dihydroxyvitamin D returned to normal values.

Multifactorial hypercalcemia and literature review on primary hyperparathyroidism associated with lymphoma

The most common cause of hypercalcemia in hospitalized patients is malignancy. Primary hyperparathyroidism most commonly causes hypercalcemia in the outpatient setting. These two account for over 90% of all cases of hypercalcemia. Hypercalcemia can be divided into PTH-mediated and PTH-independent variants. Primary hyperparathyroidism, familial hypocalciuric hypercalcemia, familial hyperparathyroidism, and secondary hyperparathyroidism are PTH mediated. The most common PTH-independent type of hypercalcemia is malignancy related. Several mechanisms lead to hypercalcemia in malignancy-direct osteolysis by metastatic disease or, more commonly, production of humoral factors by the primary tumor also known as humoral hypercalcemia of malignancy that accounts for about 80% of malignancy-related hypercalcemia. The majority of HHM is caused by tumor-produced parathyroid hormone-related protein and less frequently production of 1,25-dihydroxyvitamin D or parathyroid hormone by the tumor. We report the rare case of a patient with hypercalcemia and diagnosed primary hyperparathyroidism. The patient had persistent hypercalcemia after surgical removal of parathyroid adenoma with recorded significant decrease in PTH level. After continued investigation it was found that the patient also had elevated 1,25-dihydroxyvitamin D and further studies confirmed a large spleen mass that was later confirmed to be a lymphoma. This is a rare example of two concomitant causes of hypercalcemia requiring therapy.

Calcitriol-mediated hypercalcemia: causes and course in 101 patients

CONTEXT

Hypercalcemia mediated by 1,25-dihydroxy vitamin D (calcitriol) is uncommon, with evidence on etiology limited to small case series or case reports.

OBJECTIVE

The objective of the study was to systematically identify a large series of cases of calcitriol-mediated hypercalcemia and document the presentation, demographics, and clinical course across etiologies.

DESIGN, SETTING, AND PATIENTS

The study was a hospital-based, retrospective case series, identifying subjects from 1999 through 2009 across the public hospital system in Queensland, Australia. All patients aged over 18 years were identified that had persistent hypercalcemia associated with elevated or inappropriately normal calcitriol concentration or elevated serum angiotensin-converting enzyme.

RESULTS

A total of 101 cases were identified. Sarcoidosis was the most common etiology (49%), followed by hematological malignancy (17%) and infections (8%). Etiologies not previously described include squamous cell carcinoma of the tongue, ovarian cystadenocarcinoma, and chronic lymphocytic leukemia. Median serum angiotensin-converting enzyme was higher in sarcoid patients compared with all other causes [218 U/L (176-277) vs 155 U/L (110-208), P < .001], but a level above the normal range did not discriminate well between cases of sarcoidosis and other causes (specificity at cutoff of 130 U/L was only 31%). However, a value greater than 250 U/L was highly specific (89%) for sarcoidosis but lacked sensitivity (31%). A calcitriol level greater than 300 pmol/L was not seen in sarcoidosis but was seen with other etiologies. Cases with neoplastic etiologies were older (61.4 ± 11.4 y) than all other subjects (51.7 ± 15.0 y, P = .006).

CONCLUSIONS

Hypercalcemia mediated by calcitriol remains a rare presentation. In almost half the cases, sarcoidosis was the underlying cause, whereas a third of patients had cancer or systemic infections.

Impact of vitamin D receptor VDR rs2228570 polymorphism in oldest old

BACKGROUND

Calcitriol, a key player in the regulation of mineral metabolism, influences, directly or by increasing plasma Ca2+ and phosphate levels, a multitude of physiological functions, such as bone mineralization, cell proliferation, immune response, carbohydrate metabolism, blood pressure, platelet reactivity, gastric acid secretion, cognitive function and mood. Calcitriol is mainly effective by stimulation of the Vitamin D receptor VDR. The responsiveness of VDR may be affected by gene variants, such as the FokI polymorphism (rs2228570). The GG gene variant is expected to be more active than the GA or AA gene variant. The present study explored the impact of VDR rs2228570 on survival and health of oldest old individuals (> 90 years).

METHODS

101 individuals > 90 years were examined and genotyped. As a result, the prevalence of GG, GA & AA was 36 (10 ♂, 26♀), 52 (24 ♂, 28♀) and 13 (4 ♂, 9♀), respectively, a prevalence not significantly different from the frequency in public available dbSNP and a population (n = 208) of young volunteers (average age 49 years).

RESULTS

As compared to carriers of GG, carriers of AA and/or GA displayed significantly (p<0.05) lower diastolic blood pressure (significant only in ♂), higher instrumental activity of daily life (IADL) score and more frequent hospital visits (significant only in ♂), significantly lower prevalence of depression (significant in ♀+♂), renal disease (significant only in ♀), allergy, peptic ulcer and urolithiasis (significant only in ♂), as well as significantly higher prevalence of transitoric ischemic attacks. In a younger population a German version of the NEO-FFI, allowing reliable and valid assessment of personality, revealed decreased neuroticism (significant only in ♂) and increased extraversion in AA carriers.

CONCLUSION

The Vitamin D receptor gene variant VDR rs2228570 has only little impact on life span but may affect a variety of pathophysiologically relevant functions including mood.

Calcitriol-induced hypercalcemia in a patient with granulomatous mycosis fungoides and end-stage renal disease

An 86-year-old man, diagnosed as having mycosis fungoides in May 2008 and treated with repeated radiation therapy, was admitted to our hospital for initiation of hemodialysis due to end-stage renal disease (ESRD) in April 2012. On admission, his corrected serum calcium level was 9.3 mg/dL, and his intact parathyroid hormone level was 121.9 pg/mL (normal range 13.9-78.5 pg/mL), indicating secondary hyperparathyroidism due to ESRD. After starting hemodialysis, urinary volume diminished rapidly. The serum calcium level increased (12.7 mg/dL), and the intact parathyroid hormone level was suppressed (< 5 pg/mL), while the 1,25-dihydroxyvitamin D₃ (calcitriol) level increased (114 pg/mL, normal range: 20.0-60.0 pg/mL) in June 2012. The possibilities of sarcoidosis and tuberculosis were ruled out. Skin biopsies from tumorous lesions revealed a diagnosis of granulomatous mycosis fungoides. The serum soluble interleukin-2 receptor levels and the degrees of skin lesions went in parallel with the increased serum calcium and calcitriol levels. Therefore, the patient was diagnosed as having calcitriol-induced hypercalcemia possibly associated with granulomatous mycosis fungoides. Granulomatous mycosis fungoides is rare, and its association with calcitriol-induced hypercalcemia has not been reported. Careful attention to calcium metabolism is needed in patients with granulomatous mycosis fungoides, especially in patients with ESRD.

Mechanisms and treatment of hypercalcemia of malignancy

PURPOSE OF REVIEW

Hypercalcemia of malignancy is a common paraneoplastic syndrome and a frequent complication of advanced breast and lung cancer, and multiple myeloma. The development of this malignancy complication often purports a poor prognosis. Thorough evaluation to establish the cause of hypercalcemia is essential because some patients may actually have undiagnosed primary hyperparathyroidism.

RECENT FINDINGS

Production of humoral factors by the primary tumor, collectively known as humoral hypercalcemia of malignancy (HHM), is the mechanism responsible for 80% of cases. The vast majority of HHM is caused by tumor-produced parathyroid hormone-related protein followed by infrequent tumor production of 1,25-dihydroxyvitamin D and parathyroid hormone. The remaining 20% of cases are caused by bone metastasis with consequent bone osteolysis and release of skeletal calcium. Key therapies are saline hydration to promote calciuresis and bisphosphonates to reduce pathologic osteoclastic bone resorption. Calcitonin and glucocorticoids, especially in 1,25-dihydroxyvitamin D-mediated HHM, also have calcium-lowering effects.

SUMMARY

Recent discoveries on mechanisms of malignancy-associated hypercalcemia highlight the critical role of the osteoclast. Bisphosphonates and other novel therapies being evaluated in clinical trial target this bone-resorbing cell type and provide effective and durable serum calcium reduction.