Hydrocortisone suppression test and discriminant analysis in differential diagnosis of hypercalcaemia

Hypercalcemic crisis: a clinical review

Hypercalcemia is a common metabolic perturbation. However, hypercalcemic crisis is an unusual endocrine emergency, with little clinical scientific data to support therapeutic strategy. We review the relevant scientific English literature on the topic and review current management strategies after conducting a PubMed, MEDLINE, and Google Scholar search for articles published between 1930 and June 2014 using specific keywords: "hypercalcemic crisis," "hyperparathyroid crisis," "parathyroid storm," "severe primary hyperparathyroidism," "acute hyperparathyroidism," and "severe hypercalcemia" for articles pertaining to the diagnosis, epidemiology, clinical presentation, and treatment strategies. Despite extensive clinical experience, large and well-designed clinical studies to direct appropriate clinical care are lacking. Nonetheless, morbidity and mortality rates have substantially decreased since early series reported almost universal fatality. Improved outcomes can be attributed to modern diagnostic capabilities, leading to earlier diagnosis, along with the recognition that primary hyperparathyroidism is the most common etiology for hypercalcemic crisis. Hypercalcemic crisis is an unusual endocrine emergency that portends excellent outcomes if rapid diagnosis, medical treatment, and definitive surgical treatment are expedited.

Poor Survival Outcome With Moderate and Severe Hypercalcemia in Gynecologic Malignancy Patients

Objective:

Determine the incidence of hypercalcemia in gynecologic malignancy patients and their survival outcome.

Design:

Single-institution retrospective clinical study.

Patients and Methods:

We used Fisher exact test, Kaplan-Meier survival curves, and Cox proportional hazards model to analyze demographic and clinical data from gynecologic malignancy patients with hypercalcemia who had been treated at The University of Texas M. D. Anderson Cancer Center from September 1997 to August 2006.

Results:

Of the 5260 gynecologic malignancy patients, 268 had hypercalcemia (5%). Of the 268, 12 were excluded because of hyperparathyroidism or coexisting malignancies; thus, 256 patients were included in the study. Most patients (82%) had mild hypercalcemia. Severity of hypercalcemia was associated with disease stage (P = 0.0019), use of hypercalcemia treatment (P < 0.0001), and survival duration (P < 0.0001). The median survival duration of patients who had not been treated for hypercalcemia was 432 days compared with 106 days in patients who had been treated. The shorter survival duration of treated patients seems to result from their disease status and hypercalcemia severity rather than whether they were treated for hypercalcemia.

Conclusions:

Moderate and severe hypercalcemia is associated with poorer survival duration in gynecologic malignancy patients. Early detection and treatment of hypercalcemia in these patients may prolong survival. To our knowledge, this is the first study of hypercalcemia in patients with general gynecologic malignancy.

Cortisol and parathyroid hormone-related peptide are reciprocally modulated by negative feedback

In previous in vitro studies, we have shown that the N-terminal region of parathyroid hormone-related protein (PTHrP) can stimulate cortisol production in sea bream, Sparus auratus, interrenal tissue, possibly through a paracrine action. In the current study, the systemic interaction between cortisol and PTHrP was studied in vivo. Sustained elevated blood cortisol levels, induced either by cortisol injection or confinement stress, suppressed circulating PTHrP 6 and 24-fold, respectively, by comparison to control fish. Dexamethasone treatment reduced cortisol levels, prevented the decrease of plasma PTHrP observed in confined fish and raised plasma PTHrP levels in non-confined fish. In contrast, a single injection of (1-34) PTHrP caused a short-term (within 30 min and up to 2.5 h) decrease in plasma cortisol. The antagonistic effects between PTHrP and cortisol were substantiated by an overall (data pooled from all experiments) highly significant negative correlation (r0=-0.745, p<0.001, n=115) between the plasma levels of the two hormones. Although the underlying mechanism of the interaction still has to be determined, the high levels of PTHrP in circulation and the existence of systemic regulation favour the hypothesis that in fish PTHrP may act as an endocrine factor, although the gland that produces it still remains to be identified.

Glucocorticoids decrease the production of parathyroid hormone-related protein in vitro but not in vivo in the Walker carcinosarcoma 256 rat model

In 50-90% of cases, humoral hypercalcemia of malignancy (HHM) is due to tumor secretion of parathyroid hormone-related protein (PTHrP). Glucocorticoids are sometimes used as calcium lowering agents and there are in vitro results showing that glucocorticoids diminish PTHrP production. In this study we tested whether the serum-calcium-lowering effect of glucocorticoids is due to decreased PTHrP production by the tumor. As an animal and cell culture model we used the Walker carcinosarcoma (WCS) 256, a rat mammary carcinoma cell line producing PTHrP. In vitro, dexamethasone caused a dose-dependent inhibition of PTHrP production, whereby already 1-5 nmol/L revealed a significant decrease by WCS 256 cells. In contrast to these in vitro results, in WCS 256 tumor-bearing rats, dexamethasone (4 mg/kg body weight on day 4, and 1 mg/kg body weight from day 5 until day 7 after WCS transplantation; circulating dexamethasone levels > 20 nmol/L) did not decrease PTHrP production, PTHrP secretion, serum calcium, or tumor weight in vivo. We conclude that, in this PTHrP-mediated model of humoral hypercalcemia of malignancy, glucocorticoids do not decrease PTHrP production and secretion in vivo and do not show a calcium-lowering effect.

Medical management of hypercalcaemia

1. Hypercalcaemia is a common disorder, which frequently requires specific treatment either to control symptoms, or to prevent the development of irreversible organ damage or death. Although the best and most effective way of controlling hypercalcaemia in the long-term is to treat the underlying cause, medical antihypercalcaemic therapy is often required in clinical practice, either as a holding measure, or because the primary disease cannot itself be treated. 2. The mainstays of medical antihypercalcaemic therapy are firstly, to promote calcium excretion by the kidney by restoring extracellular volume with intravenous saline and secondly, to administer pharmacological agents which inhibit bone resorption. Measures which seek to reduce intestinal calcium absorption are seldom effective. 3. Intravenous bisphosphonates are the treatment of first choice for the initial management of hypercalcaemia, followed by continued oral, or repeated intravenous bisphosphonates to prevent relapse. These drugs have a relatively slow onset of action (1-3 days) but have potent and sustained inhibitory effects on bone resorption, resulting in a long duration of action (12-30 days). 4. Of the other agents available, calcitonin has an important place in the management of severe hypercalcaemia where a rapid effect is desirable; calcitonin is best used in conjunction with a bisphosphonate however, because of its short duration of action. Intravenous phosphate also has a place in the emergency management of severe hypercalcaemia, but is probably best reserved for patients in whom other less toxic therapies have failed. Corticosteroids are generally ineffective except in certain specific instances and are best avoided in the routine treatment of undiagnosed hypercalcaemia.

Influence of dimethyl myleran on tolerance induction and immune function in major histocompatibility complex-haploidentical murine bone-marrow transplantation

To study murine major histocompatibility complex (MHC)-haploidentical bone-marrow transplantation (BMT), B6C3F1 mice (H-2b/k) underwent BMT using syngeneic [B6C3F1 (H-2b/k)], haploidentical [CB6F1 (H-2d/b)], or fully allogeneic [DBA/2 (H-2d)] donor mice. As pretreatment, dimethyl myleran (DMM), an alkylating agent that produces effective myeloablation but little immunosuppression, was used with total body irradiation (TBI). Four conditioning regimens were studied: TBI 800 rads (1 rad = 0.01 Gy), TBI 950 rads, TBI 800 rads plus DMM (0.2 mg per mouse), and TBI 950 rads plus DMM. Survival rates, chimerism, proliferative responses in mixed-lymphocyte culture, specific cell-mediated lympholysis, and in vivo plaque-forming cell responses to several antigens were compared. TBI 800 rads plus DMM was maximally effective. Haploidentical BMT was as successful in inducing long-term survival and immune and hematologic reconstitution as was syngeneic BMT. This regimen plus haploidentical BMT of T-cell-purged marrow yielded survivors tolerant of donor and recipient major histocompatibility complex. Such myeloablation and immunosuppression prevented graft rejection, immunodeficiency due to histoincompatibility, and damage to a radiosensitive cell population. A microenvironmental influence crucial to some antibody responses was thus revealed. Delayed recovery of antibody production after BMT in humans may be due partly to suboptimal myeloablation or excess irradiation.

Multiple endocrine neoplasia type I with Cushing's disease, primary hyperparathyroidism, and insulin-glucagonoma

A case of multiple endocrine neoplasia type I (MEN I) consisting of Cushing's disease, primary hyperparathyroidism, and insulin-glucagonoma is described. This condition was treated successfully by transsphenoidal pituitary adenomectomy, subtotal parathyroidectomy, and enucleation of pancreatic tumors. Histologic features showed a basophilic adenoma in the pituitary, chief cell hyperplasia in the parathyroid, and islet cell adenomas in the pancreas. The rarity of multiple endocrine hyperfunctioning states and the pathophysiology created by the combination of these three diseases in this patient are of interest.

Clinching the diagnosis: an approach to the investigation of hypercalcemia

Hypercalcemia is a common biochemical abnormality. It is usually possible to make a presumptive diagnosis of its cause by relatively simple means. In a large majority of cases this involves differentiating between primary hyperparathyroidism and malignancy-associated hypercalcemia. Clinical evaluation and parathyroid hormone assay are particularly useful. Since the management of hypercalcemia in the short term generally involves non-specific measures such as rehydration, the inability to make an immediate accurate diagnosis presents less of a problem than might otherwise be the case. The definitive diagnosis of hyperparathyroidism, malignancy and sarcoidosis requires histological confirmation.

Hyperparathyroidism

A review of hyperparathyroidism and current controversies in diagnosis and management is presented. Accurate diagnosis by the endocrinologist and an experienced surgeon remain the standards for good surgical results. Hyperparathyroidism is a heterogeneous disease, and therapy must be individualized to each patient. Conservative surgical removal of parathyroid tissue is preferred in most patients.

Pancreatic islet cell carcinoma with hypercalcemia. Primary hyperparathyroidism or humoral hypercalcemia of malignancy

A 60-year-old woman presented with hypercalcemia and was found to have metastatic pancreatic islet cell carcinoma. Although clinical features were very suggestive of hyperparathyroidism, her parathyroid hormone levels were not elevated and no abnormal parathyroid tissue was detected by thallium-technetium or computed tomographic scanning techniques. Her hypercalcemia appeared to be due to a humoral factor--distinct from parathyroid hormone--that mimics the action of parathyroid hormone almost exactly. The various tools that may be used to differentiate primary hyperparathyroidism from the humoral hypercalcemia of malignancy are reviewed.

Value of laboratory tests in the differential diagnosis of hypercalcemia

Eighteen laboratory tests were compared in the differentiation of primary hyperparathyroidism from hypercalcemia associated with malignancy. Statistical comparisons of the test results were carried out in four patient groups and two control groups. The patient groups evaluated were those with confirmed primary hyperparathyroidism, those with malignancy with hypercalcemia, those with malignancy without hypercalcemia, and those with surgically cured primary hyperparathyroidism. These groups allowed determination of the relative diagnostic values of the tests and a rationale for their value. After exclusion of patients with renal failure from the patient and control groups, these data indicated that the laboratory tests with the greatest differential diagnostic value, in order of efficacy, were: albumin, carboxy-terminal parathyroid hormone, venous pH, cholesterol, chloride, alkaline phosphatase, phosphorus, and the chloride/phosphate ratio. Hemoglobin, hematocrit, and red blood cell count also had some value, particularly in male patients. However, none of these tests individually achieved better than an 81 percent classification accuracy. With application of logistic discriminant analysis, only three tests--albumin, parathyroid hormone, and chloride--were identified as statistically significant in jointly improving the diagnostic separation between these two patient groups. Although the 94.4 percent classification accuracy achieved by use of these three variables in a logistic discriminant function was better than that obtained with any individual variable, incorrect classification was still a significant problem, particularly in the case of patients with malignancy and high concentrations of parathyroid hormone. With the exception of albumin and chloride measurements, the commonly available ancillary laboratory tests proposed to aid this differential diagnosis do not give any more information than the analysis of parathyroid hormone alone and merely add to the increased cost of medical care.

Pulmonary carcinoid associated with a parathormone producing melanoma

A rare presentation of hypercalcemia secondary to the probable ectopic production of parathormone by a malignant melanoma associated with a pulmonary carcinoid is discussed. We suggest the association of melanoma with multiple endocrine neoplasia.

The hypercalcemia of malignancy: pathogenesis and management

The number of agents and treatment regimens which can be used in the medical treatment of hypercalcemia has increased markedly over the last 5 yr. As this list has increased, clinicians are anxious to know more about the humoral and cellular mechanisms which are responsible for the hypercalcemia of malignancy and to understand how these drugs work. Unfortunately there is no treatment available presently which is uniformally safe and effective, and the potential pathogenetic mechanisms responsible for hypercalcemia are hotly debated. In this review, we plan to summarize current views of the pathogenesis, clinical features and treatment of hypercalcemia associated with malignant disease.

Ectopic parathyroid adenomas

Two cases of parathyroid tumours occurring in unusual situations are described. Such cases may cause difficulty in both the diagnosis and the surgical treatment of hyperparathyroidism. The cases described illustrate the importance of a definitive aetiological diagnosis in hypercalcaemia, if appropriate surgery is to be performed. The value of discriminant function analysis and hydrocortisone suppression tests are discussed.