[Unusual cause of hypercalcemia in pregnancy]. / Ungewöhnliche Ursache einer Hyperkalzämie in der Schwangerschaft.

BACKGROUND: Neuroendocrine tumors (NET) diagnosed during pregnancy are extremely rare. This case report describes diagnosis and treatment of a metastasized pancreas NET that became symptomatic in the second trimester. CASE DESCRIPTION: A 33-year-old patient presented to the emergency department in the 19th week of pregnancy (WOP) with persistent diarrhea. Laboratory tests showed a pronounced hypercalcemia (3.53 mmol/l). Imaging revealed a mass in the pancreatic corpus/tail with extensive liver metastasis. Histologically, a NET (G2, SSTR-positive) with paraneoplastic parathormone-related-peptide secretion was found to be the cause of hypercalcemia. Under a treatment with octreotide, calcium values normalized and diarrhea stopped. After delivery of a healthy child (32.WOP via cesarean section) tumor progress was found. The pancreatic mass was resected completely, the liver metastases as far as possible. Postoperatively, in a CT scan, residual suspicious liver lesions could be found, and a palliative therapy with lanreotide was initiated. With this treatment, the patient has been asymptomatic for one year, and serum calcium remained normal. The child developed normally. DISCUSSION: This unusual case shows that even in extensively metastasized symptomatic NETs during pregnancy, there may be sufficient diagnostic and therapeutic options that allow for a continuation of pregnancy in close interdisciplinary cooperation under careful risk-benefit assessment for mother and child.

A Dimorphic Diagnosis of a Pleomorphic Disease: An Unusual Cause of Hypercalcemia.

BACKGROUND: Histoplasmosis is a rare cause of 1, 25-dihydroxy vitamin-D-mediated hypercalcemia. In this study, we report 2 cases of hypercalcemia secondary to histoplasmosis seen at Mayo Clinic, Rochester and a review of cases reported in the literature. METHODS: We conducted a PubMed search using the keywords "hypercalcemia" and "histoplasmosis." Fourteen cases of hypercalcemia secondary to histoplasmosis were reported between 1977 and 2020. We identified an additional 2 patients from our institution. RESULTS: We reviewed a total of 16 cases. The median age at presentation was 58.5 years (interquartile range, 41.5-68.75 years), and 13 of 16 patients (81.2%) were men. Serum parathyroid hormone level was available in 13 of 16 (81.25%) patients, of whom 11 patients (84.6%) had a low level, 1 patient (7.6%) had a normal level, and 1 patient (7.6%) had an elevated level. 1, 25-dihydroxy vitamin D level was reported in 9 of 16 (56.25%) patients. Of these, 5 patients (55.5%) had levels within normal limits, and 4 patients (44.4%) had levels above normal. Serum angiotensin-converting enzyme level was evaluated in 4 of 16 patients (25%), and it was elevated in all 4 (100%) cases. Four patients received corticosteroids before a diagnosis of histoplasmosis was made, which resulted in rapidly progressive disease and death in 2 patients. CONCLUSIONS: In patients with granulomatous disorder and hypercalcemia, it is crucial to rule out infectious etiologies before initiating steroids. Histoplasmosis can cause nonparathyroid hormone-mediated hypercalcemia and, if not suspected, may have catastrophic implications.

Calciotropic and phosphotropic hormones in fetal and neonatal bone development.

There are remarkable differences in bone and mineral metabolism between the fetus and adult. The fetal mineral supply is from active transport across the placenta. Calcium, phosphorus, and magnesium circulate at higher levels in the fetus compared to the mother. These high concentrations enable the skeleton to accrete required minerals before birth. Known key regulators in the adult include parathyroid hormone (PTH), calcitriol, fibroblast growth factor-23, calcitonin, and the sex steroids. But during fetal life, PTH plays a lesser role while the others appear to be unimportant. Instead, PTH-related protein (PTHrP) plays a critical role. After birth, serum calcium falls and phosphorus rises, which trigger an increase in PTH and a subsequent rise in calcitriol. The intestines become the main source of mineral supply while the kidneys reabsorb filtered minerals. This striking developmental switch is triggered by loss of the placenta, onset of breathing, and the drop in serum calcium.

Diagnosis, Pathophysiology and Management of Hypercalcemia in Malignancy: A Review of the Literature.

Hypercalcemia of malignancy is the most common life-threatening metabolic disorder in patients with advanced stage cancers and is a sign of poor prognosis. It usually presents with markedly elevated calcium level and is severely symptomatic. It is associated with hematological malignancies, such as multiple myeloma, non-Hodgkin lymphoma, leukemias and solid cancers, particularly renal and breast carcinomas as well as squamous cell carcinomas of any organ. Several mechanisms have been implicated in the development of hypercalcemia of malignancy amongst them the osteolytic related hypercalcemia, parathyroid hormone-related peptide (PTHrP) mediated hypercalcemia, extrarenal 1,25 dixydroxyvitamin D (calcitriol) mediated hypercalcemia and parathyroid hormone (PTH) related hypercalcemia either ectopic in origin or in patients with parathyroid carcinoma. Clinical history and and physical examination could point towards the correct diagnosis confirmed by the above-mentioned biochemical mediators of hypercalcemia. Early diagnosis and treatment lowering calcium levels in the blood can improve symptoms and the quality of life of these patients and avoid delays for further antitumor therapy.

A Diet Rich in Fish Oil and Leucine Ameliorates Hypercalcemia in Tumour-Induced Cachectic Mice.

BACKGROUND: Dietary supplementation with leucine and fish oil rich in omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) has previously been shown to reduce cachexia-related outcomes in C26 tumour-bearing mice. To further explore associated processes and mechanisms we investigated changes in plasma Ca2+ levels, the involvement of parathyroid hormone related protein (PTHrP), and its possible interactions with cyclooxygenase 2 (COX-2). METHODS: CD2F1 mice were subcutaneously inoculated with C26 adenocarcinoma cells or sham treated and divided in: (1) controls, (2) tumour-bearing controls, and (3) tumour-bearing receiving experimental diets. After 20 days, body and organ masses and total plasma Ca2+ levels were determined. Furthermore, effects of DHA, EPA and leucine on production of PTHrP were studied in cultured C26 cells. RESULTS: The combination of leucine and fish oil reduced tumour-associated hypercalcemia. Plasma Ca2+ levels negatively correlated with carcass mass and multiple organ masses. DHA was able to reduce PTHrP production by C26 cells in vitro. Results indicate that this effect occurred independently of COX-2 inhibition. CONCLUSION: Our results suggest that cancer-related hypercalcemia may be ameliorated by a nutritional intervention rich in leucine and fish oil. The effect of fish oil possibly relates to a DHA-induced reduction of PTHrP excretion by the tumour.

Hypercalcemia of Malignancy in a Dog Diagnosed With Cholangiocellular Carcinoma.

A 4-year-old, neutered male Golden Retriever was presented with a 1-week history of weight loss, polyuria, and polydipsia. The diagnostic workup showed an increased ionized calcium concentration, mild increase in serum creatinine and urea concentration, and severe hyperlipasemia. A complete abdominal ultrasound revealed multiple hepatic nodules. A cytological diagnosis of malignant epithelial neoplasia, highly suggestive of bile duct adenocarcinoma was made. In order to confirm the presumptive diagnosis of hypercalcemia of malignancy due to the presence of a hepatic neoplasia, serum parathormone-related peptide concentration was measured, and the result revealed an increased concentration. The dog was hospitalized and received supportive treatments consisting of intravenous furosemide and fluid therapy. After ruling out lymphoma and hypoadrenocorticism, oral prednisone was initiated and ionized calcium concentration decreased gradually down to normal concentration after 7 days of hospitalization. Chemotherapy with intravenous epirubicin was initiated based on the cytological diagnosis. One month after diagnosis and due to the worsening of its clinical condition, the dog was humanely euthanized. Postmortem examination confirmed a cholangiocellular carcinoma. To our knowledge, this is the first report of malignant hypercalcemia associated with cholangiocellular carcinoma in a dog.

Reducing Pup Litter Size Alters Early Postnatal Calcium Homeostasis and Programs Adverse Adult Cardiovascular and Bone Health in Male Rats.

The in utero and early postnatal environments play essential roles in offspring growth and development. Standardizing or reducing pup litter size can independently compromise long-term health likely due to altered milk quality, thus limiting translational potential. This study investigated the effect reducing litter size has on milk quality and offspring outcomes. On gestation day 18, dams underwent sham or bilateral uterine vessel ligation surgery to generate dams with normal (Control) and altered (Restricted) milk quality/composition. At birth, pups were cross-fostered onto separate dams with either an unadjusted or reduced litter size. Plasma parathyroid hormone-related protein was increased in Reduced litter pups, whereas ionic calcium and total body calcium were decreased. These data suggest Reduced litter pups have dysregulated calcium homeostasis in early postnatal life, which may impair bone mineralization decreasing adult bone bending strength. Dams suckling Reduced litter pups had increased milk long-chain monounsaturated fatty acid and omega-3 docosahexaenoic acid. Reduced litter pups suckled by Normal milk quality/composition dams had increased milk omega-6 linoleic and arachidonic acids. Reduced litter male adult offspring had elevated blood pressure. This study highlights care must be taken when interpreting data from research that alters litter size as it may mask subtle cardiometabolic health effects.

Parathyroid hormone independent hypercalcemia in adults.

Parathyroid independent hypercalcemia is characterized by suppressed parathyroid hormone (PTH) in the presence of hypercalcemia. Well known causes and mechanisms are redistribution of calcium from the skeleton, by malignant diseases; inadequately increased intestinal calcium uptake mediated by increased vitamin D activity, and reduced renal elimination due to medications. Frequent and infrequent causes are discussed, and more recent mechanistic models presented in this review. Most hypercalcemic conditions are stable and in equilibrium between the different organs, whereas the utmost severe cases are characterized by rapid rising calcium levels and renal failure, resulting in a vicious circle where a disequilibrium state is developed. Management and treatment depends on the underlying condition and severity. The aim of this review is to discuss non-parathyroid hypercalcemic conditions as seen in the modern clinic, with a focus on areas where recent gain of knowledge has been achieved.

[CME: Paraneoplastic Endocrine Syndromes]. / CME: Paraneoplastische endokrine Syndrome.

CME: Paraneoplastic Endocrine Syndromes Abstract. Paraneoplastic endocrine syndromes are caused by ectopic hormone production by malignant tumor cells. Knowledge of paraneoplastic endocrine syndromes may allow a timely diagnosis of the underlying cancer at a treatable stage and, on the other hand, appropriate treatment of the endocrine manifestations reduces morbidity and mortality of the affected patients. The most common endocrine syndromes are paraneoplastic hypercalcaemia, caused by the secretion of PTHrP, and hyponatremia, caused by the inadequate secretion of ADH. Although there may be clinical symptoms like fatigue, nausea/vomiting and renal insufficiency for hypercalcaemia and gait disturbances and mental alterations for hyponatremia, the diagnosis must be confirmed by laboratory testing and prompt the search for associated tumors.

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.

Gestational Gigantomastia Complicated by PTHrP-Mediated Hypercalcemia.

Context: Gestational gigantomastia is an uncommon condition characterized by abnormal and excessive growth of breast tissue during an otherwise uncomplicated pregnancy. Gestational gigantomastia may be accompanied by hypercalcemia, which in some cases has been associated with elevated serum levels of PTHrP. The source of the PTHrP in these cases has been suggested to be the enlarged breasts. Objective: To describe the rapid resolution of hypercalcemia and normalization of serum PTHrP after elective termination of pregnancy, indicating that the placenta was the source of the PTHrP. Design: A retrospective analysis of clinical and biochemical data over a 2-year interval and review of literature. Setting: An academic medical center. Patient: A 33-year-old G8P4 female who presented at week 8 of pregnancy with gestational gigantomastia and subsequently developed marked hypercalcemia at week 13. Serum levels of PTH were suppressed but circulating PTHrP was elevated. There was no history of hypercalcemia or significant breast growth during previous pregnancies. Intervention: Hypercalcemia was poorly responsive to IV saline, prednisone, calcitonin, and cinacalcet. She requested termination of pregnancy at week 20. Results: Serum levels of calcium, PTH, and PTHrP normalized within 48 hours of termination of pregnancy. Conclusion: The rapid resolution of hypercalcemia after termination of pregnancy, despite persistent gigantomastia, provides evidence for a pathologic role of the placenta in the excess production of PTHrP, possibly through an as yet uncharacterized placenta-breast hormonal axis.

Serotonin induces parathyroid hormone-related protein in goat mammary gland.

During lactation, large amounts of calcium are exported from the mammary gland into milk to ensure skeletal growth of the offspring. Recent studies revealed that serotonin (5-HT) is essential to stimulate skeletal calcium resorption for milk synthesis. Our objective was to explore the correlation between circulating 5-HT and serum calcium and parathyroid hormone-related protein (PTHrP) concentrations around parturition in dairy goats. We also investigated the effect of 5-HT on PTHrP expression in cultured primary goat mammary epithelial cells (GMEC). Blood samples of multiparous Guanzhong dairy goats were collected on day -5 to 3 postpartum for analysis of serum concentrations of calcium, 5-HT, and PTHrP. Results revealed that from day -3 to 0 postpartum serum calcium and 5-HT concentrations decreased progressively, but serum PTHrP concentration only had a sharp drop in the postpartum period sampled. Correlation analysis of circulating 5-HT and serum calcium and PTHrP concentrations on day 1 and 2 postpartum revealed that low serum 5-HT concentration was positively correlated with serum total calcium or PTHrP concentration. By knocking down tryptophan hydroxylase-1 (TPH1) or adding 5-hydroxytryptophan (5-HTP) to decrease or increase the levels of 5-HT in GMEC, we observed that 5-HTP increased PTHrP expression in a dose-dependent manner and siTPH1 decreased PTHrP protein expression. Furthermore, 5-HT increased mRNA abundance of calcium-sensing receptor (CaSR) in a dose-dependent manner and decreased the expression of plasma membrane Ca2+ ATPase-1 (PMCA1). Taken together, 5-HT seems to induce PTHrP expression in goat mammary cells during and after parturition. These findings suggest that increasing 5-HT biosynthesis could be a potential therapeutic target for prevention of hypocalcemia in dairy goats.

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.

PSA-alpha-2-macroglobulin complex is enzymatically active in the serum of patients with advanced prostate cancer and can degrade circulating peptide hormones.

BACKGROUND: Prostate cancer cells produce high levels of the serine protease Prostate-Specific Antigen (PSA). PSA is enzymatically active in the tumor microenvironment but is presumed to be enzymatically inactive in the blood due to complex formation with serum protease inhibitors α-1-antichymotrypsin and α-2-macroglobulin (A2M). PSA-A2M complexes cannot be measured by standard ELISA assays and are also rapidly cleared from the circulation. Thus the exact magnitude of PSA production by prostate cancer cells is not easily measured. The PSA complexed to A2M is unable to cleave proteins but maintains the ability to cleave small peptide substrates. Thus, in advanced prostate cancer, sufficient PSA-A2M may be in circulation to effect total A2M levels, levels of cytokines bound to A2M and hydrolyze small circulating peptide hormones. METHODS: Total A2M levels in men with advanced prostate cancer and PSA levels above 1000 ng/mL were measured by ELISA and compared to controls. Additional ELISA assays were used to measure levels of IL-6 and TGF-beta which can bind to A2M. The ability of PSA-A2M complexes to hydrolyze protein and peptide substrates was analyzed ± PSA inhibitor. Enzymatic activity of PSA-A2M in serum of men with high PSA levels was also assayed. RESULTS: Serum A2M levels are inversely correlated with PSA levels in men with advanced prostate cancer. Il-6 Levels are significantly elevated in men with PSA >1000 ng/mL compared to controls with PSA <0.1 ng/mL. PSA-A2M complex in serum of men with PSA levels >1000 ng/mL can hydrolyze small fluorescently labeled peptide substrates but not large proteins that are PSA substrates. PSA can hydrolyze small peptide hormones like PTHrP and osteocalcin. PSA complexed to A2M retains the ability to degrade PTHrP. CONCLUSIONS: In advanced prostate cancer with PSA levels >1000 ng/mL, sufficient PSA-A2M is present in circulation to produce enzymatic activity against circulating small peptide hormones. Sufficient PSA is produced in advanced prostate cancer to alter total A2M levels, which can potentially alter levels of a variety of growth factors such as IL-6, TGF-beta, basic FGF, and PDGF. Alterations in levels of these cytokines and proteolytic degradation of small peptide hormones may have profound effect on host-cancer interaction.

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.

[Metabolic disorders as paraneoplastic syndromes]. / Metabolische Entgleisungen als paraneoplastische Syndrome.

Paraneoplastic syndromes are characterized by the tumor-induced release of peptide hormones and/or the initiation of immune phenomena, which elicit clinical changes and alterations in laboratory parameters independent of the tumor size and spread. In addition to neurological, endocrinal and rheumatological phenotypes, metabolic alterations play a special role in the clinical routine as they commonly present with acute symptoms in an emergency situation and necessitate immediate diagnosis and prompt initiation of treatment. Metabolic alterations within the framework of malignant diseases should be treated in a multidisciplinary team and it is often necessary to perform monitoring and treatment in an intensive care unit. This article focuses on the diagnostic and therapeutic options for metabolic disorders due to paraneoplastic syndromes, such as hypercalcemia, hypocalcemia, hyperglycemia, hypoglycemia and a special variant of tumor-induced metabolic disorders due to tumor lysis syndrome.

Parathyroid hormone related protein concentration in human serum and CSF correlates with age.

BACKGROUND: Parathyroid Hormone-Related Protein (PTHrP) is involved in intracellular calcium (Ca) regulation, and has been demonstrated to participate in regulation of Ca in brain cells, activation of neurons, and modulation of pain. However, there are conflicting reports regarding the presence of PTHrP in CSF. DESIGN AND METHODS: PTHrP and Ca were quantified in paired CSF and serum samples using mass spectrometry-based methods. Associations between PTHrP and Ca concentrations with age, sex and concentrations of nine CSF diagnostic markers in a set of 140 paired serum and CSF patient samples were evaluated. RESULTS: The observed median PTHrP concentration in CSF was 51 times higher than in serum; the median concentration of Ca in CSF was 1.8 times lower than in serum. We observed positive correlation between concentrations of PTHrP in CSF and serum (p=0.013). Distribution of PTHrP concentrations in serum was associated with age (p=0.0068) and the concentrations were higher in women. In samples with serum calcium concentrations within the reference intervals (n=118), central 95% distribution of concentrations for Ca-CSF, PTHrP-serum and PTHrP-CSF were 5.4 (4.5-6.1) mg/dL, 1.2 (0.5-2.5) pmol/L, 62 (22-125) pmol/L, respectively. CONCLUSIONS: Our data demonstrate that PTHrP is a normal constituent of human CSF with median concentrations 51 fold higher than in serum. Elevated serum PTHrP concentrations were positively correlated with age and significantly higher in women. Our data suggest that CSF could be a significant source of circulating PTHrP.