PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “PARATHYROID DISEASES”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

Allelic loss in parathyroid neoplasia can help characterize malignancy.

Parathyroid carcinoma can be difficult to diagnose, and the final pathologic diagnosis relies on clinicopathologic correlation. Clinical features of malignancy include high preoperative calcium levels and an intraoperative impression that the gland is adherent to local structures. Histologic features of malignancy include increased mitoses, vascular invasion, and broad bands of fibrosis. This study used molecular genotyping to assess parathyroid neoplasia for loss of heterozygosity across a panel of known tumor suppressor genes that have been previously identified as being important in the pathogenesis of parathyroid diseases. Parathyroid adenomas, hyperplasia, and carcinomas were included in the study, and a fractional allelic loss was calculated for each lesion. Losses of 1q25, 7q13.3, 10q23, 13q14.3, and 11p15.5 were particularly prevalent. In addition, almost all adenomas and carcinomas had loss of the markers for 1p. The benign parathyroid diseases (adenomas and hyperplasia) had low mean fractional allelic loss (11% and 15%, respectively). The parathyroid carcinomas, in contrast, showed high mean fractional allelic loss (63%). This difference in the mutational profile suggests that this type of assay may be useful as an adjunctive diagnostic test in cases of parathyroid neoplasia.

Adenoma↗

[Primary hyperparathyroidism: diagnostic and therapeutic trends].

The most interesting aspects of parathyroid disease are the increased incidence of primary hyperparathyroidism, which nowadays is diagnosed more and more frequently through the casual discovery of hypercalcaemia, the various diagnostic methodologies used, the ongoing debate as to the function of parathyroidectomy in asymptomatic patients and the new video-assisted surgical techniques which have recently been developed. The authors retrospectively review 31 consecutive cases of primary hyperparathyroidism. The clinical onset was characterised in 26 cases by an osteoarthralgic syndrome associated with renal and biliary pathology. Five cases were asymptomatic. Prior to surgery, all patients underwent both biochemical and instrumental tests. MIB scintigraphy was found to yield the most reliable diagnosis, leading to identification of 83.6% of diseased parathyroids. As regards surgical treatment, 29 cases were treated with a simple parathyroidectomy, 1 with a bilateral inferior parathyroidectomy and 1 with a thyroid lobectomy. Associated thyroid surgery was performed in 8 cases for concomitant thyroid disease: 1 total thyroidectomy, 2 subtotal thyroidectomies and 5 lobectomies. In 3 cases radioimmunoguided surgery was used. There were no cases of mortality, and 9.6% of patients presented specific morbidity characterised by some degree of paraesthesia. As stated by other researchers, the authors argue that MIBI scintigraphy is the most reliable test for the diagnosis of hyperparathyroidism and that surgical treatment is the first choice for symptomatic primary hyperparathyroidism. The surgical strategy depends on the abnormality underlying the hyperparathyroidism: in the event off an adenoma, a bilateral exploration of the neck and removal of the diseased parathyroid are required; in the case of hyperplasia, a subtotal parathyroidectomy is necessary with marking of the residual parathyroid which will simplify any possible reoperation; in the event of carcinoma, a thyroid loboisthmectomy and ipsilateral parathyroidectomy are performed with removal of the fatty tissue of the antero-superior mediastinum and ipsilateral cervical functional lymphadenectomy.

Adult↗

Ultrastructure of human parathyroid cells in health and disease.

Parathyroid glands (n = 271) removed from 130 patients were examined by light and electron microscopy. A standardized method of tissue processing was employed and morphometry was performed. The aim of the paper is to provide a description of the human parathyroid chief cell ultrastructure in health and disease, with quantitative evaluation of structures involved in secretion of parathyroid hormone in a large case series, and to discuss their role in current diagnostic histopathology. The patients were euparathyroid (n = 10), or affected by primary (n = 97), secondary (n = 8), or tertiary (n = 15) hyperparathyroidism. In normal glands, solid parenchyma was composed of chief cells, large clear cells, transitional-oxyphil cells, and oxyphil cells. Chief cell hyperplasia, pseudo-adenomatous hyperplasia, adenoma, water-clear cell hyperplasia, and carcinoma were the most usual forms of parathyroid disease responsible for primary hyperparathyroidism. In chief cell hyperplasia, all the parathyroid glands were enlarged and the chief cells were in an active state of hormone secretion, with a large Golgi complex, abundant rough endoplasmic reticulum (RER), small lipid droplets, and tortuous plasma membrane. In pseudo-adenomatous hyperplasia, one gland was enlarged and the others displayed a normal size; however, electron microscopic examination and morphometric analysis showed that all the glands had active cells. Adenomas displayed a pattern similar to those of pseudo-adenomatous hyperplasia, with one gland enlarged and the others of normal size. However, ultrastructural examination and morphometry showed that the normal-size glands were hypo-active. Water-clear cell hyperplasia showed cells filled with cytoplasmic vacuoles. In these cells, structures with intermediate features between secretory granules and vacuoles were visible. Nucleo-cytoplasmic atypias were frequently visible in parathyroid carcinoma cells. In secondary and tertiary hyperplasia, active chief cells were regularly mixed with oxyphil or transitional-oxyphil cells. The tertiary hyperplasia was characterized by RER-associated structures that were not found in the normal or other pathological conditions. These results demonstrate that electron microscopy and morphometry represent useful tools in parathyroid histopathology.

Adult↗

Early postoperative calcium levels as predictors of hypocalcemia.

OBJECTIVE: Early, safe postoperative hospital discharge has become a priority in the current environment of cost containment and managed care. One determinant for this following operations of the thyroid or parathyroid glands is a stable postoperative calcium level. This study sought to determine whether early postoperative calcium levels could safely predict hypocalcemia following operations of the thyroid or parathyroid glands. STUDY DESIGN: A retrospective chart review of 197 patients undergoing such operations was undertaken. METHODS: The study population was divided into patients undergoing parathyroid exploration with removal of one or more glands for parathyroid disease ("parathyroid" group) and patients undergoing bilateral thyroid operations ("nonparathyroid" group). Postoperative calcium levels were plotted as a function of time, and the slope between the first two postoperative calcium levels examined. RESULTS: A positive slope predicted normocalcemia in 100% of "nonparathyroid" and 90% of "parathyroid" surgeries. A negative slope was predictive in its magnitude. The nonparathyroid patients who developed postoperative hypocalcemia had an average slope significantly more negative (-0.84% change/h) than patients remaining normocalcemic (-0.49% change/h) (P = .03). Similarly, the parathyroid patients who became hypocalcemic had an average initial slope nearly twice as negative (-1.4% change/h) as patients remaining normocalcemic (-0.78% change/h) (P = .005). CONCLUSIONS: These results indicate that an initial upsloping postoperative calcium curve based on two early postoperative calcium measurements is strongly predictive of a stable postoperative calcium level, and a steeply downsloping initial calcium curve is worrisome for eventual hypocalcemia.

Calcium↗

Accuracy of methods to estimate ionized and "corrected" serum calcium concentrations in critically ill multiple trauma patients receiving specialized nutrition support.

BACKGROUND: The purpose of this study was to determine the accuracy of 22 published methods to estimate serum ionized calcium (iCa) and "corrected" total serum calcium (totCa) concentrations in critically ill, multiple trauma patients. Seven of these formulas estimated iCa and 15 were directed toward predicting a "corrected" totCa. METHODS: Adult patients admitted to the trauma intensive care unit who received specialized nutrition support were consecutively recruited for study. Patients who received blood products, i.v. calcium, or therapeutic doses of heparin within 24 hours before the laboratory measurements or had a history of cancer, bone disease, parathyroid disease, hyperphosphatemia (> or = 6 mg/dL), hyperbilirubinemia (> 3.5 mg/dL), or renal failure requiring dialysis were excluded. The 22 published methods were analyzed for sensitivity, specificity, percentage false negatives, and percentage false positives for predicting hypocalcemia or hypercalcemia. RESULTS: One hundred patients were studied 4.9 +/- 3.3 days postinjury and were receiving enteral nutrition (n = 81), parenteral nutrition (n = 18), or both (n = 1) at the time of study. Twenty-one patients were hypocalcemic (iCa < or = 1.12 mmol/L) and 6 were hypercalcemic (iCa > or = 1.32 mmol/L). The mean sensitivity of the 22 methods for assessing hypocalcemia was 25% +/- 32% and the specificity was 90% +/- 18%. Although the average percentage of false positives for assessing hypocalcemia was 10% +/- 18%, the mean percentage of false negatives was inordinately high at 75% +/- 32%. The most common method for determination of "corrected" totCa concentration ["corrected" calcium = totCa + (0.8 x (4-serum albumin concentration))] had a sensitivity of only 5%. The McLean-Hastings nomogram method, the most common method for estimating serum iCa concentration, had a sensitivity of 67% but unfortunately also had a significant false-positive rate of 27%. Serum totCa correlated modestly with iCa (r2 = .334, p < .001). Those patients with a serum albumin < or = 2 g/dL (n = 43) had a significantly higher prevalence of hypocalcemia than those with a higher serum albumin concentration (37% incidence of hypocalcemia vs 10%, respectively, p < .002). CONCLUSIONS: Aberrations in calcium homeostasis are frequent (27%) in postresuscitative critically ill multiple trauma patients. Methods for predicting hypocalcemia lack sensitivity and are often associated with an unacceptable rate of false negatives. Predictive methods for estimating ionized or corrected serum concentrations should not be used. Direct measurement of serum iCa concentration is indicated for assessing calcium status for this population.

Adult↗

[Radionuclide imaging of parathyroid adenoma using the 201TI-99mTc substraction scintigraphy method].

Primary hyperparathyroidism is the most frequent parathyroid disease. Parathyroid adenomas account for the majority of primary hyperparathyroidism (81%) while carcinoma and diffuse hyperplasia occur less frequently (4% and 15%). Ten per cent of adenomas are located substernally. The difficulties of preoperative localization of parathyroid adenomas may lead to incomplete surgical removal. Therefore an accurate technique for preoperative localization of the parathyroid gland is of utmost importance. Various imaging methods are available (ultrasonography, computer tomography, angiography, etc.), each with their own limitations. Thus, a nuclear technique performed via 201Tl-99mTc dual isotope subtraction scintigraphy may well contribute to the safety of diagnostics. The authors present a case of parathyroid adenoma diagnosed by this method and confirmed histologically. The role of non-invasive techniques in preoperative localization of parathyroid adenomas protecting the patient from invasive procedures and repeated surgical explorations is highly emphasized.

Adult↗

In situ correlation of synthesis and storage of parathormone in parathyroid gland disease.

The distribution and expression of parathyroid hormone (PTH) were investigated in normal and abnormal parathyroid tissue. PTH was detected using a monoclonal antibody with specificity for the 44-68 region of the PTH molecule. Prominent reactivity for PTH was seen in normal parathyroid with a granular pattern of staining. Active parathyroid tissue (adenoma and hyperplasia) showed much less reactivity for PTH, although there was prominent reactivity in the normal tissue around adenomas. Comparison of expression of PTH with that of parathormone mRNA showed a reciprocal pattern in normal tissue and, to a less marked extent, in abnormal tissue. Parathyroid carcinoma in particular had coinciding areas of PTH and PTH mRNA expression. Oxyphil cells had little or no PTH expression, except in the associated 'colloid' in some cases. The findings indicate an inverse relationship between storage and cellular synthesis of PTH, this being more marked in physiological than in pathological conditions of the parathyroid.

Adenoma↗

Triazolopyrimidine (trapidil), a platelet-derived growth factor antagonist, inhibits parathyroid bone disease in an animal model for chronic hyperparathyroidism.

Parathyroid bone disease in humans is caused by chronic hyperparathyroidism (HPT). Continuous infusion of PTH into rats results in histological changes similar to parathyroid bone disease, including increased bone formation, focal bone resorption, and severe peritrabecular fibrosis, whereas pulsatile PTH increases bone formation without skeletal abnormalities. Using a cDNA microarray with over 5000 genes, we identified an association between increased platelet-derived growth factor-A (PDGF-A) signaling and PTH-induced bone disease in rats. Verification of PDGF-A overexpression was accomplished with a ribonuclease protection assay. Using immunohistochemistry, PDGF-A peptide was localized to mast cells in PTH-treated rats. We also report a novel strategy for prevention of parathyroid bone disease using triazolopyrimidine (trapidil). Trapidil, an inhibitor of PDGF signaling, did not have any effect on indexes of bone turnover in normal rats. However, dramatic reductions in marrow fibrosis and bone resorption, but not bone formation, were observed in PTH-treated rats given trapidil. Also, trapidil antagonized the PTH-induced increases in mRNA levels for PDGF-A. These results suggest that PDGF signaling is important for the detrimental skeletal effects of HPT, and drugs that target the cytokine or its receptor might be useful in reducing or preventing parathyroid bone disease.

Animals↗

Recurrent parathyroid cystic disease.

Cystic masses of the neck may represent thyroid, parathyroid, thyroglossal duct or branchial cleft cysts. Analysis of the cyst fluid may establish the etiology. Elevated levels of parathyroid hormone can be found in parathyroid cysts without concomitant hyperparathyroidism. A high concentration of cholesterol without the finding of thyroglobulin or parathyroid hormone in the fluid aspirated from a lateral neck mass suggests a branchial cleft cyst.

Adult↗

Nuclear medicine in diagnosis and treatment of diseases of the head and neck. I. Salivary and parathyroid gland disease and one identification and staging of head and neck tumors.

The advent of both improved imaging systems and new radioactive agents has increased the effectiveness of nuclear medicine in diagnosing and treating diseases of the head and neck. In this first in a series of two articles, the role of nuclear medicine is discussed in the evaluation of diseases of the salivary and parathyroid glands, and in the identification and staging of head and neck tumors. Radionuclide studies of the salivary glands are useful in the identification of tumors and the evaluation of gland function. Such studies are a valuable adjunct in the diagnosis of Sjögren's syndrome and of acute and chronic inflammatory disease. Radionuclide imaging also has been helpful in the detection of adenomata and hyperplasia of the parathyroid glands and often complements ultrasonography localization procedures. The advent of gallium-67 imaging has improved the staging of head and neck tumors.

Gallium Radioisotopes↗

The conservative management of primary hyperparathyroidism.

Sixty-eight patients with mild primary hyperparathyroidism were studied for a mean period of 4.5 years (median 3.3). Seven of these patients presented with renal colic while the rest had no symptoms. There was no significant deterioration in mean serum creatinine, total calcium or ionized calcium concentrations during this period. No patient had progressive renal stone or parathyroid bone disease. Hypertension was defined as a systolic or diastolic blood pressure greater than one standard deviation from the age-sex mean, or if hypotensive drugs were required. Thirty-nine per cent were hypertensive at presentation and 42 per cent became hypertensive later. Four patients died from causes unrelated to hypercalcaemia and three required parathyroidectomy when serum calcium concentration rose above 3.0 mmol/l. Patients over 55 with mild asymptomatic primary hyperparathyroidism may be managed conservatively for several years without significant renal impairment, progressive stone disease, parathyroid bone disease or worsening hypercalcaemia. We suggest that observation in these patients could be restricted to six-monthly checks of physical state, blood pressure and serum biochemistry, particularly concentration of calcium creatinine and alkaline phosphatase.

Adult↗

Results of surgical and medical treatment in primary hyperparathyroidism.

The success rate of surgical treatment in large series of p-HPT is about 95%. The usual reasons for failure are insufficient exploration of the neck and unrecognized multiple gland involvement. Such failures might be avoidable. Persistent HPT after an adequate neck dissection may be due to a diseased gland in the anterior mediastinum or within the parenchyma of the thyroid. There are also a few cases with true recurrent disease. If a reoperation is required localization studies can be helpful. The success rate in the present reoperative series was 94% showing that most patients with p-HPT can be cured by surgery. The rate of hypoparathyroidism after reoperative surgery can be minimized by autotransplantation of diseased parathyroid tissue. There are no current medical substitutes for the surgical management of p-HPT.

Adenoma↗