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Query: UMLS:C0221002 (primary hyperparathyroidism)
 4,921 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Most cases of primary hyperparathyroidism are due to either a parathyroid adenoma or to parathyroid hyperplasia. Parathyroid carcinoma is a very rare cause of hyperparathyroidism. Although the diagnosis of parathyroid carcinoma is usually established based on pathological criteria of vascular and capsular invasion, some clinical and biochemical features differentiate it from benign forms of hyperparathyroidism. We report the case of a middle-aged woman with a long standing history of nephrolithiasis, who presented with a palpable neck mass, weight loss, severe hypercalcemia and hypophosphatemia, as well as very high serum levels of intact parathyroid hormone. Surgical neck exploration revealed a large tumor that invaded trachea, esophagus, reccurrent laryngeal nerve, right apical pleura and right carotid artery. Pathological examination confirmed the invasive nature of the tumor. Along with the case report, we review the literature and discuss the diagnostic and therapeutic options of this rare condition.
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PMID:Primary hyperparathyroidism due to parathyroid carcinoma. 920 27

On the basis of recent advances in our understanding of the pathogenesis of chronic renal failure, imaging of parathyroid hyperplasia in chronic dialysis patients has become a highly useful tool not only for identification, but also for evaluation of the nature of abnormal glands and for various intervention strategies. Rational imaging approaches, different from those used for primary hyperparathyroidism, should be established for secondary hyperparathyroidism.
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PMID:Imaging of the parathyroid in chronic renal failure: diagnostic and therapeutic aspects. 926 83

A retrospective chart review of 43 patients who underwent technetium 99m (Tc-99m) sestamibi scans from June 1995 to January 1997 was performed. Only those who underwent subsequent parathyroid exploration with excision were included in the study. Twenty subjects (13 women and seven men) were included in the study. Ages ranged from 21 to 84 years (mean, 58 years). All patients had laboratory values and clinical findings consistent with primary hyperparathyroidism. Two patients had preoperative magnetic resonance imaging (MRI) scans (one patient with recurrent disease), and one had a preoperative computed tomography (CT) scan. The remaining patients had the sestamibi scan as the only preoperative localization study. There were 18 pathologic diagnoses of parathyroid adenoma and two of parathyroid hyperplasia. Sestamibi failed to correctly identify the location of the parathyroid lesion in two cases. In 18 cases the preoperative sestamibi scan correctly localized the lesion, a predictive value of 90%. We conclude that the Tc-99m sestamibi scan is an accurate preoperative tool that can be used as a single modality to localize parathyroid adenomas.
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PMID:Diagnostic value of the preoperative sestamibi scan in intraoperative localization of parathyroid adenomas: a case study. 959 36

Primary hyperparathyroidism is unusual in children. It is most commonly due to a solitary sporadic parathyroid adenoma, though parathyroid hyperplasia and related familial syndromes should be considered. In the case presented here, an 11-year-old boy with primary hyperparathyroidism had preoperative imaging studies that localized to the inferior aspect of the left side of the neck anteriorly, and a parathyroid adenoma was successfully resected. Screening for familial syndromes involving hyperparathyroidism should be individually considered in children with primary hyperparathyroidism. Preoperative localizing studies and the role of unilateral surgery are controversial issues in adults with primary hyperparathyroidism. Although such issues have not been addressed in children, localization and unilateral surgery proved successful in this case.
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PMID:Management of primary hyperparathyroidism in children. 959 59

Clonal analysis has shown that in renal hyperparathyroidism (2-HPT), parathyroid glands initially grow diffusely and polyclonally after which the foci of nodular hyperplasia are transformed to monoclonal neoplasia. There is a great deal of information about genetic abnormalities contributing to the tumourigenesis of parathyroid neoplasia in primary hyperparathyroidism. It is speculated that allelic loss of the MEN1 suppressor gene and overexpression of cyclin D1 induced by rearrangement of the parathyroid hormone gene may be the major genetic abnormality in sporadic parathyroid adenoma but not in 2-HPT. The pathogenesis of 2-HPT, abnormality of the Ca2+-sensing receptor (CaR) gene and the vitamin D receptor gene may possibly contribute to parathyroid tumourigenesis in 2-HPT. However, this is not yet clear and heterogeneous and multiple genetic abnormalities may be responsible for the progression of secondary parathyroid hyperplasia.
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PMID:Mechanism of parathyroid tumourigenesis in uraemia. 1004 55

The incidence of persistent or recurrent primary hyperparathyroidism reported in the literature lies between 1 and 10%. The main causes are represented by atypical locations or incorrect diagnosis of primary parathyroid hyperplasia. Since primary parathyroidectomy by an experienced surgeon has a success rate of 95%, there is no need for extended imaging studies prior to initial bilateral exploration. After confirming diagnosis of persistent or recurrent hyperparathyroidism exact localization studies are necessary. The most important procedures are ultrasonography, magnetic resonance imaging, technetium Tc99m sestamibi scintigraphy with a combined sensitivity of approximately 90%. In case of negative imaging results selective venous catheterization before reoperation can be performed. Reoperation by an experienced surgeon will be successful in 95% of cases.
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PMID:Diagnostic strategies and surgical procedures in persistent or recurrent primary hyperparathyroidism. 1054 8

Parathyroid excess may happen as a result of autonomous overactivity of the parathyroid glands (primary hyperparathyroidism). Secondary hyperparathyroidism is the consequence of chronic hypocalcemia, leading to parathyroid hyperplasia. Long-lasting secondary hyperparathyroidism may turn to autonomy in the sense of tertiary hyperparathyroidism. In primary hyperparathyroidism indications for surgical intervention are renal, intestinal or osseous organ manifestations, as well as relevant clinical symptoms of the so-called hypercalcemic syndrome. In truly asymptomatic primary hyperparathyroidism, observation is justified. However, the patients need regular supervision. If there is progression indicating health risk, the strategy must switch from observation to operation. Secondary hyperparathyroidism has must be treated by surgery if renal osteodystrophy progresses or tertiary hyperparathyroidism develops.
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PMID:[Definition of hyperparathyroidism and indication for surgical therapy]. 1055 Mar 36

In primary hyperparathyroidism (pHPT), parathyroidectomy is the treatment of choice, but anatomic variations of ectopic glands may cause surgical failure. Reliable preoperative noninvasive localization procedures would have a positive impact on the operative time and increase recovery rate. We retrospectively evaluated 186 patients with pHPT who were studied before successful parathyroidectomy by double tracer scintigraphy (99mTc-pertechnetate+201TI chloride or 99mTc-pertechnetate +99mTc-sestamibi, 160 patients), ultrasonography (148 patients) and computerized tomography (CT) scan (92 patients). During bilateral neck exploration, 159 (85.5%) single adenomas, 6 (3.2%) parathyroid carcinomas, and 3 (1.6%) double adenomas were found. Moreover, 18 (9.7%) patients had diffuse chief cells parathyroid hyperplasia. Removed parathyroid glands were in ectopic sites in 41 (22.0%) cases, mainly localized in the upper mediastinum or behind the esophagus. The overall sensitivity was 83.5 and 85.2% for 99mTc-pertechnetate+201TI chloride and 99mTc-pertechnetate+99mTc-sestamibi scintigraphy respectively, 80.4% for CT scan and 81.1% for ultrasonography. In patients with ectopic glands, sensitivity was 81.2, 79.5, 73.3 and 81.6% respectively. In 36 out of 41 patients with ectopic glands in whom the removed parathyroids were correctly localized, mean operative time was 95 min, and in 5 patients without preoperative localization it was 260 min. In conclusion, in pHPT, preoperative localization of an enlarged parathyroid is helpful, especially in ectopic adenomas and in anatomic variations in location, and it has been proved to reduce operative time and morbidity rate.
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PMID:Noninvasive localization procedures in ectopic hyperfunctioning parathyroid tumors. 1073 95

Total or subtotal parathyroidectomy is considered the treatment of choice for multiple endocrine neoplasia type I (MEN-I)-associated primary hyperparathyroidism (HPT). However, persistent or recurrent HPT is frequently observed. The development of a rapid two-site immunoradiometric assay (IRMA) method for measuring intact parathormone (PTH) has provided a valuable tool for recognizing possible surgical failures. Our experience includes 16 MEN-I patients (10 females, 6 males) of mean age 35.5 years operated on between 1990 and 1996. Total parathyroidectomy (TPTX) with autotransplantation of parathyroid tissue was the standard treatment. Blood samples for PTH measurement were drawn at the induction of anesthesia (basal value), 10 and 20 minutes after the removal of each gland, and 60 minutes after TPTX. Rapid PTH measurement, which required only 15 minutes of incubation at 37 degrees C, showed a highly significant correlation (p < 0.0001) with the standard method. Circulating PTH levels exhibited a stepwise decrease during TPTX, reaching a mean value of 22.3% of the baseline 20 minutes after removal of the last gland. Two patients showed a prompt decrease of PTH after removal of the single enlarged gland, featuring the kinetics observed in the adenomas. One of these two patients was successfully treated with more conservative surgery. None of the patients showed persistence or recurrence of HPT. In our experience, intraoperative measurement of PTH seems to be a valuable adjunct in both the diagnosis of multiglandular involvement and the prediction of surgical treatment in patients with primary parathyroid hyperplasia.
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PMID:Intraoperative parathormone measurement in patients with multiple endocrine neoplasia type I syndrome and hyperparathyroidism. 1078 76

Primary hyperparathyroidism is the third most frequent endocrine disorder. The condition required for diagnosis is inappropriately elevated secretion of parathyroid hormone (PTH) with respect to calcemia. Most often, the disease is due to a parathyroid adenoma, i.e. a monoclonal benign parathyroid tumor, less often to a parathyroid hyperplasia. The main tumorogenic mechanisms currently proposed are a DNA rearrangement in the PTH locus (transposition of the PTH promoter upstream to Cyclin D1/PRAD 1 gene) and a mutation of the gene responsible for multiple endocrine neoplasia type I. The clinical presentation has strikingly evolved towards a milder, asymptomatic form, frequently diagnosed on systematic screenings. Though the mechanism of hypercalcemia is better understood, several hypothesis are still being considered about the regulation of tumoral PTH secretion: the role of the expression of calcium-receptor in parathyroid gland cells, vitamin D receptor and estrogen receptor polymorphisms, etc. Surgery is still advised for symptomatic forms of the disease, either because of a bone involvement, or because of an evolutive nephrolithiasis. In the near future, the new calcium-receptor agonists could be a relevant therapeutic approach.
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PMID:[Primary hyperparathyroidism]. 1111 7


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