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Query: UMLS:C0020437 (hypercalcemia)
 10,293 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Parathyroid carcinoma is an uncommon malignancy. It accounts for less than 1% of cases of primary hyperparathyroidism (HPT). It is manifested by severe hypercalcemia and up to 50% of patients will have concomitant kidney or bone disease. The etiology of parathyroid carcinoma is unknown, however, the recently discovered HRPT2 gene, a tumor suppressor gene encoding for the protein parafibromin, has been implicated in the pathogenesis. Identification of inactivating germ-line mutations in HRPT2 has significant implications for diagnosis and management. This article summarizes the genetic aspects of parathyroid carcinoma, reviews its clinical manifestations, and outlines the principles of surgical therapy, the indications for adjuvant therapy, and the use of bisphosphonate and calcimimetic agents for management of hypercalcemia.
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PMID:Parathyroid carcinoma. 1571 75

Parathyroid carcinoma is a rare tumor that is responsible for <1% of cases of hyperparathyroidism in most parts of the world. An increased incidence of this tumor has been reported in patients with the hyperparathyroidism-jaw tumor (HPT-JT) syndrome, but the etiology of most other cases is unknown. Parathyroid carcinomas tend to occur a decade earlier than adenomas, and the sex ratio approaches unity in contrast to the female preponderance of adenomas. Most patients with carcinomas present with marked hypercalcemia and are more likely to have associated bone and renal disease than those with adenomas. Although fibrosis and mitotic activity are common in carcinomas, these features are not specific for malignancy. The diagnosis of carcinoma should be restricted to those tumors that show invasion of blood vessels, perineural spaces, soft tissues, thyroid gland, or other adjacent structures or to tumors with documented metastases. Mutations of the HRPT2 gene (1q21-q32), which are responsible for the HPT-JT syndrome, have been implicated in the development of a high proportion of parathyroid carcinomas. A subset of patients with mutation-positive carcinomas have germline mutations of the HRPT2 gene. This finding suggests that some patients with apparent sporadic parathyroid carcinomas may have the HPT-JT syndrome or a variant of this syndrome. Because of the high frequency of local recurrence following incomplete excision, an en bloc resection is the preferred surgical approach for treatment of parathyroid carcinomas.
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PMID:Parathyroid carcinoma: an overview. 1573 73

Parathyroid carcinoma is an uncommon cause of primary hyperparathyroidism; however, when this condition is severe, cancer must be suspected. We report on a 28-year-old male with severe hypercalcemia, cachexia, acute pancreatitis, urolithiasis, anemia and a severe skeletal involvement with multiple fractures. The patient had a 4-cm parathyroid tumor, that was surgically excised, along with the ipsilateral thyroid lobe. During the postoperative period, he had a severe and prolonged hungry bone syndrome, with a slow recovery of fractures, with functional and anatomical sequelae in the extremities. PTH levels were adequate for the serum calcium during the 16 months of follow-up.
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PMID:[Primary hyperparathyroidism with severe skeletal involvement in one patient with parathyroid carcinoma]. 1576 53

Parathyroid carcinoma is very rare and when diagnosed can be difficult to treat as more than 50 per cent have persistent or recurrent disease. Patients generally present with profound symptoms of hypercalcaemia and a palpable neck mass. We describe a case of parathyroid carcinoma in primary hyperparathyroidism and a case in tertiary hyperparathyroidism in a renal dialysis patient. Most studies in the literature are retrospective but recent trends in presentation, treatment options and complications have been reviewed and are summarized in this paper.
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PMID:Parathyroid carcinoma: a report of two cases and a concise review and update of the literature. 1617 89

Parathyroid carcinoma is a rare condition, comprising less than 1% of the cases of primary hyperparathyroidism (PHP). Nonetheless, due to its aggressiveness, and having prognosis dependent on the precocity of diagnosis and radical therapeutic approach, it is paramount that the clinical suspicion be made before surgery. Clinical presentation is typical of severe PHP, with a parathyroid tumor >1.5 cm, usually palpable. The pathologic features sometimes are difficult to characterize. Our experience with this condition (from 1983 to 2004) includes 7 cases, all symptomatic, hypercalcemic syndrome and bone disease present in most of them. In 6/7 the tumor was palpable, and in all the biochemical profile was compatible with severe PHP. Three patients died of complications of hypercalcemia. Recent findings point to a mutation on the gene HRPT2 as the molecular base for the development of this kind of tumor. The therapeutic approach is surgical and should include ipsilateral thyroidectomy and cervical exploration in order to find possible local metastasis. Post-surgical complications (mainly hypocalcemia) are proportional to the pre-existing metabolic alterations. The long-term prognosis depends upon the precocity of diagnosis, surgical success and control of hypercalcemia. New therapeutic approaches, based on bisphosphonates and calcimimetic drugs, as well as the possibility of genetic diagnosis, tend to ameliorate the prognosis of this severe affection.
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PMID:[Parathyroid carcinoma]. 1693 1

Parathyroid carcinoma is a rare disease accounting for 1 to 5% of parathyroid neoplasms. This malignant tumour must be suspected when a severe primary hyperparathyroidism occurs with high hypercalcemia and elevated parathormon levels. At this time, a cervical mass is often palpable. Both head and neck ultrasonography and 99mTc-sestamibi scintigraphy are the best preoperative imaging tests to suspect and localize the tumour. Surgical approach with simultaneous tumorectomy and hemithyroidectomy, completed by selective neck dissection (level VI) is the treatment of choice. An elective lateral neck dissection should be performed if necessary. Tumour control should be monitored by regular measurement of calcium and parathormon levels. Local recurrence or metastasis risk is 30 to 70% and the 5 year overall survival about 50 to 80%. In case of recurrence, aggressive surgical management should be applied and adjuvant radiation therapy may be discussed.
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PMID:[Parathyroid carcinoma]. 1656 15

Parathyroid carcinoma is a rare etiology of primary hyperparathyroidism characterized by severe clinical symptoms of hypercalcemia and markedly elevated serum parathormone levels. Nonfunctioning parathyroid carcinoma is an inactive form of the disease. There are less than 30 reports of nonfunctioning parathyroid carcinoma in the English literature and the association with parathyroid adenoma has not been described. This report describes a patient with concurrent nonfunctioning parathyroid carcinoma and a functioning parathyroid adenoma.
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PMID:Concurrent nonfunctioning parathyroid carcinoma and parathyroid adenoma. 1664 86

Carcinoma of the parathyroid is a rare malignancy that can be cured surgically if the proper diagnosis and treatment is given initially. Arriving to the clinical suspicion of a malignancy preoperatively is by far the most important step for a good prognosis. Our goal is to review the correlation between clinical and final histopathological findings that can arouse the suspicion of such malignancy and their true predictive value in the diagnosis. All patients that underwent surgical removal of the parathyroid mass between March of 1992 and March of 2003 were reviewed retrospectively at Providence Hospital and Medical Centers. Among 168 patients who underwent parathyroid excision, 14 (8.3%) had hyperplasia of the parathyroid, 121 (72%) had benign adenoma, 25 (14.8%) had other benign lesions, and 8 (4.7%) patients had primary carcinoma of the parathyroid confirmed by pathology. Our mean serum calcium level was 11.57 mg/dL, which was lower than the mean level (12 mg/dL) for benign hyperparathyroidism. The mean tumor size was 2.18 cm, smaller than the proposed for malignant criteria, and none of the eight patients (0%) had any symptoms of hypercalcemia at the time of diagnosis. Seven of eight patients (87.5%) had frank signs of invasion together with other histological features, and two patients had associated papillary carcinoma of the thyroid. Five patients from our series did not meet clinical criteria for malignancy (tumor size > 3 cm, palpable mass, and serum calcium > 14 mg/dL), but had undisputable histological findings (high mitotic pattern, fibrous trabeculae, capsular invasion, vascular invasion, and nodular involvement). On the other hand, 17 patients with benign histology had tumors greater than 3 cm, and an additional 18 had palpable masses on physical examination. We believe that these patients need to be followed closely. The patients with diagnosis of parathyroid carcinoma, their kindred, and those with large adenomas may benefit from genetic screening for HRTP2 gene mutations in search of early detection of tumors suspicious for malignancy. This is based on the fact that we did not find correlation between the clinical presentation and the histological features in our patients with proven malignancy.
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PMID:Correlation between clinical and histological findings in parathyroid tumors suspicious for carcinoma. 1671 97

(1) Patients who require dialysis for chronic renal failure develop phosphocalcium metabolic disorders that often lead to secondary hyperparathyroidism. Standard treatment consists of a phosphate chelator and vitamin D, along with the use of an appropriate calcium concentration in the dialysis bath, but is difficult to manage. (2) Parathyroid cancer is a rare malignancy frequently associated with hypercalcaemia. (3) Cinacalcet is a calcimimetic agent that reduces the parathormone level. Clinical evaluation includes more than a dozen dose-finding studies and clinical trials. The optimal dose seems to range from 30 to 180 mg/day and varies widely from one patient to another. (4) 3 double-blind placebo-controlled trials, lasting for a maximum of one year and involving a total of 1136 dialysis patients with chronic renal failure, showed no improvement in quality of life with cinacalcet. The target parathormone level was reached by 40% of patients on cinacalcet versus 5% of patients on placebo, while the effects of cinacalcet on calcium levels (-7%) and phosphate levels (-8%) were modest. No impact on bone complications is mentioned in available reports. (5) The assessment of treatment of parathyroid cancer is limited to one ongoing non comparative trial involving 21 patients. (6) During clinical trials, 11% of dialysis patients had low parathormone levels, creating a risk of adynamic bone disease and fractures, but available data are sparse. (7) Two-thirds of patients receiving cinacalcet have episodes of hypocalcaemia, which may in part account for reports of seizures (1.4% of patients), nausea (31%) and vomiting (27%). Many adverse effects seen in animal studies have not been adequately investigated in the clinical setting, such as an increase in the QT interval, thyroid disorders, and sexual dysfunction. Cinacalcet is a powerful CYP 2D6 inhibitor and is also metabolised by isoenzymes CYP 3A4 and CYP 1A2, creating an increased risk of drug interactions. (8) In practice, treatment with cinacalcet seems difficult to manage and to provide only limited benefits. Available assessment reports leave many questions unanswered, and this is a further reason not to use this product outside of clinical trials, either after failure of phosphate chelator and vitamin D therapy (especially as an alternative to surgery) or in parathyroid cancer.
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PMID:Cinacalcet: new drug. Secondary hyperparathyroidism: where are the clinical data? 1676 95

Parathyroid carcinoma constitutes less than 1 % of primary hyperparathyroidism. The male to female ratio is approximately equal and the mean age at presentation is 40 years. In about half of the patients there is a palpable cervical mass, and serum calcium level is usually above 14 mg/dl. In a case report we present a 21-year-old man with a non-tender, non-mobile bulging mandibular mass. He suffered from fatigue, recent weight loss, hoarseness, polydipsia, polyuria, hematuria, recurrent renal stones and bouts of constipation and diarrhea. A mandibular biopsy confirmed brown tumor. Serum calcium level was 15.4 mg/dl. Cervical ultrasound revealed a hypoecho area suspicious of parathyroid adenoma. Parathyroid carcinoma was later confirmed and en bloc resection was performed. During a two-year follow up there has been no evidence of recurrence or hypercalcemia. This unique case of parathyroid carcinoma in conjunction with brown tumor is the second reported case worldwide.
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PMID:Parathyroid carcinoma: A rare case with mandibular brown tumor. 1677 84


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