Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0221002 (primary hyperparathyroidism)
 4,921 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Parathyroid carcinoma is a rare tumor responsible for 0.5-5% of primary hyperparathyroidism. It is usually small (not more than 27 g) and the precise diagnosis of malignancy is made when local or distant metastases are found. We describe a case of a 37 yr old male presenting with a substernal goiter and no specific symptoms except hypertension. This mass had cysts and calcifications and it was in the anterior upper mediastinum. The patient had severe hypercalcemia (Ca greater than 14 mg/dl), high PTH levels and mild renal failure. Bone scanning showed signs of hyperparathyroidism. The patient was subjected to total thyroidectomy and removal of the mass en block. The tumor was circumscribed lobulated and mostly cystic. It weighed 1,200 g (380 g after evacuation of cysts) and measured 12 x 9 x 4.5 cm. Histologic examination showed a highly differentiated adenocarcinoma of parathyroid with metastasis in a regional lymph node. Almost 4 years later the patient is alive and well without hypercalcemia and without evidence of distant metastases.
 ...
PMID:Large parathyroid functioning carcinoma (1,200 g) presenting as a substernal goiter. 156 Jan 89

Primary hyperparathyroidism and malignancy are responsible for the majority of reported cases of hypercalcemia. Suspected hypercalcemia should be documented on more than one occasion, preferably with the measurement of ionized calcium. Determination of intact parathyroid hormone with a modern two-site immunoassay is the single most important laboratory analysis in the differential diagnosis of hypercalcemia. Intact parathyroid hormone is increased or inappropriately high in primary hyperparathyroidism and suppressed or low normal in hypercalcemia of malignancy. Midregion and carboxylterminal radioimmunoassays are less effective in separating parathyroid and nonparathyroid hypercalcemia. In malignancy, hypercalcemia may result from local osteolysis or humoral factors. Although ectopic parathyroid hormone is produced rarely and certain lymphomas secrete 1,25-dihydroxyvitamin D, parathyroid hormone-related protein is elevated in the majority of patients with humoral hypercalcemia of malignancy. Recent developments in the measurement of parathyroid hormone-related protein should help to define the physiologic function of parathyroid hormone-related protein and its role in the differential diagnosis and therapy of hypercalcemia.
 ...
PMID:Hypercalcemia and parathyroid disorders. 159 19

We report a family with primary hyperparathyroidism in four patients in two generations with apparent autosomal dominant transmission. A fifth member was probably affected. Two cases had definite parathyroid carcinoma (PC), and two had parathyroid adenoma with atypical features that could represent an early stage of cancer. In each of our patients, one parathyroid gland was abnormal. Five other parathyroid glands (in two patients) were normal in histology and size. There was no evidence of neoplasia in other tissues. Constitutional karyotypes were normal in all four patients. We identified three chromosomal abnormalities (a reciprocal translocation between chromosomes 3 and 4, trisomy 7, and a pericentric inversion in chromosome 9) in cultured PC tissue from one patient. These chromosomal changes are of unclear significance. Analyses on tumor DNA from one case of PC and one of atypical adenoma showed no evidence of ras gene mutations, PTH gene rearrangement, or allelic loss from chromosome 11q13 (locus of the gene for multiple endocrine neoplasia type 1). This family shows susceptibility to cancer without antecedent hyperplasia in all parathyroids. It could help identify a novel tumor susceptibility gene.
 ...
PMID:Studies in a kindred with parathyroid carcinoma. 163 36

In this immunoradiometric assay (IRMA) of parathyrin (PTH) a polyclonal anti-amino-PTH(1-34) is the capture antibody and a radiolabeled monoclonal anti-hPTH(44-68) is the second antibody. Gel filtration of serum from a hyperparathyroid patient yielded only a single peak of PTH, corresponding to the elution position of synthetic PTH(1-84). Healthy elderly individuals (ages 78 +/- 5 y, mean +/- SD, n = 45) had PTH concentrations (21 +/- 13 ng/L) not significantly higher than those from healthy younger (38 +/- 11 y) adults (20 +/- 8 ng/L, n = 94). Assay results agreed well with those obtained with a carboxyl-terminal PTH assay both in normal subjects (r = 0.63, P less than 0.001) and in patients with primary hyperparathyroidism (r = 0.59, P less than 0.001). Both assays equally discriminated patients with surgically confirmed primary hyperparathyroidism from normal individuals, but the PTH(1-84) IRMA also allowed a nearly absolute discrimination between normal subjects and patients with primary hypoparathyroidism (undetectable serum PTH in 18 of 21 cases) and secondary hypoparathyroidism (caused by hypercalcemia that was caused by a malignant tumor, PTH 1.3 +/- 1.3 ng/L, n = 32). Moreover, the PTH(1-84) IRMA is more sensitive (detection limit in serum, 0.8 ng/L) and easier and quicker to perform than the carboxyl-terminal assay.
 ...
PMID:Immunoradiometric assay of parathyrin with polyclonal and monoclonal region-specific antibodies. 168 22

We developed and validated a radioimmunoassay for circulating human parathyroid hormone-related peptide (PTHrP), based on a commercial antiserum to the synthetic 1-34 fragment of PTHrP, 125I-Tyr degrees-PTHrP(1-34) as radioligand, and prior extraction of the native peptide from plasma with C-2 cartridges. We determined immunoreactive PTHrP concentrations in plasma samples from 48 healthy persons (mean +/- SD, 3.1 +/- 1.0 pmol/liter; range, less than 2 to 5 pmol/liter), 8 patients with primary hyperparathyroidism, 36 patients with hypercalcemia and a concurrent malignant lesion, and 9 normocalcemic patients with cancer and increased serum levels of carcinoembryonic antigen or prostate-specific antigen. PTHrP was normal in samples from patients with primary hyperparathyroidism (3.2 +/- 1.1 pmol/liter), secondary hyperparathyroidism (2.5 +/- 1.3 pmol/liter), and cancer without hypercalcemia (2.4 +/- 1.0 pmol/liter). In contrast, plasma immunoreactive PTHrP levels were increased (6.0 to 85.0 pmol/liter) in 47% of patients with hypercalcemia and cancer of various types, with or without bone metastatic lesions. Large amounts of PTHrP were also found in conditioned medium from cultured human prostatic carcinoma cells. Thus, PTHrP may be a causative factor for hypercalcemia associated with a malignant lesion in at least half of the cases. Measurement of circulating PTHrP may be of differential diagnostic help in hypercalcemic states.
 ...
PMID:Parathyroid hormone-related peptide in plasma of patients with hypercalcemia and malignant lesions. 223 3

The two most frequent causes for hypercalcemia are primary hyperparathyroidism and hypercalcemia associated with malignancy. Elevated or inappropriately high PTH serum levels are the hallmark of hyperparathyroidism. Sensitive immunometric assays for the secreted, biologically active, intact parathyroid hormone molecule, PTH-(1-84), employ two populations of region-specific antibodies, take advantage of saturation kinetics rather than competitive binding, and have many technical advantages over conventional radioimmunoassay. Approximately 90% of patients with primary hyperparathyroidism have elevated serum levels of PTH-(1-84) by immunometric assay; the remainder have inappropriately elevated values of PTH for the serum calcium concentration. Clinical correlation studies comparing measurements of PTH using antisera that recognize the carboxyl, midregion, or amino terminus of PTH with PTH levels determined by immunometric assays demonstrate elevated values in equivalent numbers of hyperparathyroid individuals. Immunometric assays for PTH-(1-84) have their greatest value in separating patients with hyperparathyroidism from those with hypercalcemia of malignancy. In earlier studies using region-specific antisera, there was virtually always an overlap of serum PTH levels in hyperparathyroidism and hypercalcemia associated with malignancy. In contrast, analysis of results using PTH-(1-84) immunometric assays in several hundred reported patients shows a complete separation of PTH values. Clinical judgment, combined with measurement of PTH in the setting of hypercalcemia, can lead to the diagnosis of hyperparathyroidism with confidence in essentially all patients.
 ...
PMID:Immunoassays for parathyroid hormone 1-84 in the diagnosis of hyperparathyroidism. 172 83

The incidence of parathyroid carcinoma in patients surgically treated for primary hyperparathyroidism at the University of Michigan Hospital was 0.4% during an 18-year period. The courses of the five patients with metastatic disease are described. Histologic reevaluation and assessment of the DNA ploidy pattern were performed in each case. Localization studies preceded all reexplorations. The number of operative procedures in each patient ranged from two to 10. Two patients are living with recurrent disease and one has been disease free for 42 months. Two patients died after 2 and 12 years, respectively. Three patients had aneuploid tumors; one had a diploid tumor. One patient had both aneuploid and diploid cell populations. Dilemmas in diagnosis, localization, and medical and surgical management were encountered in patients with metastatic carcinoma. The chosen treatment should be evaluated individually in each case because of the variability in aggressiveness of this malignancy. Surgical resection proved most effective in some of these patients for both local and distant recurrences. Bisphosphonates and gallium nitrate have been reported to be effective in controlling hypercalcemia. Only the former had some effect in one of our patients.
 ...
PMID:Metastatic parathyroid carcinoma: dilemmas in management. 174 86

The differential diagnosis of hypercalcemia has expanded to over 25 separate disease states, with primary hyperparathyroidism and malignancy accounting for 80-90% of all hypercalcemic patients. Primary hyperparathyroidism comprises the majority of hypercalcemic patients among the ambulatory population, but malignancy accounts for up to 65% of such patients in the hospital. Factors favoring primary hyperparathyroidism include a family history of hyperparathyroidism or multiple endocrine neoplasia, a history of childhood radiation to the head and neck, the postmenopausal state, a history of renal calculi or peptic ulcer, hypertension, the induction of hypercalcemia by thiazides, or an asymptomatic patient with a prolonged, stable mild hypercalcemia. The usefulness of the serum calcium, parathyroid hormone, chloride, phosphorus, serum 25-OHD, and 1,25-(OH)2D, and urinary calcium in the differential diagnosis of hypercalcemia is discussed. The pitfalls of an excessive reliance on the serum PTH in diagnosing hyperparathyroidism are stressed. The discriminant values of the serum calcium, chloride, phosphorus, and parathyroid hormone are explored, with the serum parathyroid hormone, chloride, and calcium proving most useful in separating primary hyperparathyroidism from other forms of hypercalcemia. Multivariate discriminant analysis using the serum calcium, phosphorus, and chloride and the hematocrit achieves an accuracy of 95-98% and is the most economical method of identifying hyperparathyroidism. The addition of the amino-terminal or intact PTH assay increases the accuracy to 99% and is essential in the presence of renal insufficiency.
 ...
PMID:Differential diagnosis of hypercalcemia. 176 70

Parathyroid carcinoma is a rare cause of primary hyperparathyroidism. However, to our best knowledge, at least 163 cases of functioning parathyroid carcinoma appeared in the English literature from 1981 to 1989. We summarize the available information obtained from the reports of those patients and compare it with previous descriptions of the disease. The etiology of parathyroid carcinoma is usually obscure, but the possibility of a radiation-induced malignant change in the parathyroid gland became evident in a few patients. Clinical manifestations, including age, sex, symptoms, and biochemical findings in this review were comparable to those in previous reviews. Noninvasive localization studies such as ultrasonography may offer a diagnostic clue to parathyroid carcinoma. Measurement of DNA content is a useful adjunct for making the histologic diagnosis of parathyroid carcinoma and prediction of the clinical outcome. Since the initial operation offers the best chance for cure, pre-operative suspicion and intra-operative recognition of the parathyroid cancer are essential. The initial operation should be en bloc resection of the tumor, avoiding rupture of the tumor capsule and spillage of tumor cells. As parathyroid carcinoma is a slow-growing but tenacious malignancy, repeated resection of local recurrent tumors or even distant metastases is effective for palliation of recurrent hypercalcemia and occasional cure. When hypercalcemia is refractory to surgical therapy or no recurrent tumor can be identified, other modalities of therapy must be considered. New drugs to control hypercalcemia by inhibiting bone resorption may hold promise in patients with recurrent parathyroid carcinoma.
 ...
PMID:Diagnosis and treatment of patients with parathyroid carcinoma: an update and review. 176 40

In hospitalized patients primary hyperparathyroidism (HPT) and neoplasms account for more than 90% of all hypercalcemias. Measurements of parathyroid hormone, particularly when combined with dynamic tests using calcitonin and EDTA have a high specificity and sensitivity in the differential diagnosis of hypercalcemia but are time-consuming and costly for screening purposes. Most chemical autoanalyzers beside serum calcium also measure serum chloride, phosphate and albumin. In order to evaluate how these simple variables could differentiate between HPT and hypercalcemia due to malignant disorders, 110 measurements from HPT subjects and 111 measurements from cancer patients with hypercalcemia were used. Serum chloride was best among the simple variables to separate the two disorders and classified 84% of the hypercalcemic subjects correctly. When serum phosphatase and albumin were added giving the formula (serum chloride-84) x (albumin-15)/phosphate, only 3% of the cancer and 4% of the HPT subjects were misclassified when borderline values (400-500) were excluded (5% of the sample). In conclusion, while other more sensitive and expressive tests exist to establish the cause of hypercalcemia the above mentioned formula is a cheap and easy screening test for a preliminary diagnosis.
 ...
PMID:Serum chloride in the differential diagnosis of hypercalcemia. 177 37


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>