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

The effect of acute hypercalcemia on blood pressure and plasma catecholamine levels was investigated in 10 normal subjects and in 5 patients completely thyroparathyroidectomized (TPTX) for a parathyroid cancer. In normal subjects, calcium infusion (15 mg/kg over 3 h) significantly increased plasma calcium and epinephrine levels and blood pressure. Plasma norepinephrine was increased only after 3 h of calcium infusion. In TPTX patients, calcium infusion increased significantly plasma calcium and epinephrine but not blood pressure. The percent increase in mean blood pressure during calcium infusion correlated with the concomitant percent increase in serum calcium in normal subjects (r = 0.71, p less than 0.001) but not in TPTX patients (r = -0.08). These data are in agreement with the hypothesis that the effect of calcium on arterial pressure is realized under intact parathyroid function.
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PMID:Blood pressure effects of acute hypercalcemia in normal subjects and thyroparathyroidectomized patients. 406 86

The immunoreactive forms of parathyroid hormone (iPTH) in the plasma of six patients with primary, adenomatous hyperparathyroidism and six patients with ectopic hyperparathyroidism due to non-parathyroid cancer were compared by using gel filtration on columns of Bio-Gel P-150 and radioimmunoassay of iPTH in eluted fractions after concentration. We found much less (p<0.001) small (mol wt<9,500) COOH-terminal fragments of iPTH in plasma samples from ectopic hyperparathyroid patients (0.52+/-0.13 ng eq/ml) than in samples from primary hyperparathyroid patients (3.70+/-1.15 ng eq/ml). The quantity of iPTH eluting with or before native bovine PTH [1-84] was the same in both syndromes (ectopic hyperparathyroidism, 0.82+/-0.22 ng eq/ml; primary hyperparathyroidism, 0.73+/-0.09 ng eq/ml), and these values correlated positively with plasma calcium concentration (ectopic hyperparathyroidism, r=0.908; primary hyperparathyroidism, r=0.919). In both syndromes, plasma samples had an iPTH component that eluted well before PTH [1-84] (mol wt 9,500), but this component was present in much larger quantities in three patients with ectopic hyperparathyroidism. We conclude that (a) the decreased quantity of biologically inactive COOH-terminal fragments of iPTH circulating in ectopic hyperparathyroidism accounts for the previously reported relatively lower total serum iPTH values in this syndrome as compared with primary hyperparathyroidism (Riggs et al. 1971. J. Clin. Invest. 50: 2079); (b) there appears to be sufficient iPTH with presumed biologic activity to account for the hypercalcemia in both syndromes; (c) a large PTH component, not previously recognized in plasma, is present in both ectopic and primary hyperparathyroidism and may exist as the predominant immunoreactive form of the hormone in some patients with ectopic hyperparathyroidism.
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PMID:Immunoreactive forms of circulating parathyroid hormone in primary and ectopic hyperparathyroidism. 483 87

Parathyroid carcinoma is a rare cause of hyperparathyroidism. Cure results from successful en bloc resection. However, because of its rarity, the malignant nature may not be appreciated at the initial operative procedure and as a result, definitive resection may not be accomplished. However, even with extensive en bloc resections, local recurrences do occur and patients die of metabolic derangements associated with hypercalcemia. Thus in addition to operative intervention, palliative chemotherapy may be required to control the hypercalcemia. Radiotherapy has been unsuccessful. A single case of nonfunctioning parathyroid carcinoma responding to treatment with methotrexate, Adriamycin, cyclophosphamide, and CCNU has been reported. We report a case of recurrent functioning parathyroid carcinoma treated with dacarbazine (DTIC) in which biochemical and pathologic evidence of at least a partial response was seen. The patient, a 33-year-old woman, had undergone five previous neck explorations during a 26-month period for aggressive locally recurrent disease. Before DTIC therapy the intact parathyroid hormone (PTH) level was 1032 pg Eq/ml (normal 163 to 347 pg Eq/ml) and the serum calcium level was 16.8 mg/dl (normal 8.8 to 10.0 mg/dl). After a course of DTIC there was a marked improvement in her clinical status and biochemical parameters (intact PTH 545 pg Eq/ml; serum calcium 11.8 mg/dl). For 2 months her condition stabilized, with PTH levels between 700 and 760 pg Eq/ml and serum calcium levels between 10.2 and 16.0 mg/dl. With a slowly progressive rise in biochemical parameters a second course of DTIC was initiated and a marked drop in serum calcium levels (5.7 mg/dl) occurred, but PTH levels remained unchanged. A progressive course of septicemia, malnutrition, and disseminated intravascular clotting ultimately lead to her death 4 weeks later. At autopsy examination the tumor was confined to the neck. Grossly and microscopically there was extensive central as well as peripheral necrosis of the tumor, which was thought to be the result of the cytotoxic effect of DTIC. From this experience and because of the grim prognosis in patients with recurring parathyroid carcinoma, it may be that aggressive use of chemotherapy with DTIC early in the course of treatment should be considered.
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PMID:Parathyroid carcinoma: biochemical and pathologic response to DTIC. 650 66

Parathyroid carcinoma is rare and hits diagnosis often difficult. A case is reported, remarkable by the age of the patient (17 years), and the main peculiarities of the disease are reviewed: frequency of complete bone syndrome, palpable tumour of the neck, calcemia more than 140 mg/l, occurrence of recurrent palsy; relapsing course, death being dependent on hypercalcemia rather than metastasis; median survival time about five years, non influenced by chemotherapy. Ultrastructural study, previously realized in about thirty cases, is specially evaluated: it seems able to concur on anatomopathologic diagnosis, when assertion of malignancy is difficult.
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PMID:[Secreting parathyroid carcinoma. Apropos of a case]. 666 12

The second reported case of carcinoma of the parathyroid gland in a child 15 years of age or younger is presented. This case is also remarkable in its extremely unusual presentation with seizures, theorized to be associated with hypercalcemia and/or a negative magnesium balance.
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PMID:Parathyroid carcinoma in a child: unusual presentation with seizures. 672 79

Seven cases of functioning and two cases of nonfunctioning parathyroid carcinoma are presented together with a general discussion of this disease. Functioning parathyroid carcinoma may be associated with prolonged survival. The morbidity and mortality from this disease are generally related to the prolonged hypercalcemia that occurs. The hypercalcemia is best treated with excision of local recurrences; however, this surgery is most often palliative and seldom curative. The best operative results were obtained when the disease could be localized preoperatively. Neck and mediastinal exploration in the absence of physical or radiographic evidence of recurrence failed to affect serum calcium levels. Two patients with nonfunctioning parathyroid cancer did poorly compared with those with functioning parathyroid carcinoma. The few cases reported in the literature are also suggestive of a more aggressive disease. The failure of this tumor to produce parathyroid hormone may allow it to escape clinical attention until it has achieved an advanced state.
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PMID:Parathyroid carcinoma: a clinical study of seven cases of functioning and two cases of nonfunctioning parathyroid cancer. 705 35

During a 20 year period, 27 patients have undergone reoperations for primary hyperparathyroidism. Hypercalcemia has been successfully controlled in 21 of the 27 patients after a total of 64 operations. Reasons for failure at initial exploration included surgical error in 12, multiple gland disease in five, unusual parathyroid gland location in five, carcinoma of the parathyroid gland in two and unknown in three. A variety of techniques were used to localize missing parathyroid glands prior to reoperation. Selective venous sampling was the most helpful but gave correct localizing information in only nine of 18 patients. Postoperatively, hypoparathyroidism was temporary in two patients and permanent in four. Recurrent laryngeal nerve injury was temporary in one patient, permanent and unilateral in two and bilateral in one patient. Reoperations for hyperparathyroidism are associated with increased morbidity and decreased success. Most importantly, failure at the initial operation is preventable in most patients.
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PMID:Reoperations for hyperparathyroidism. 724 50

Parathyroid carcinoma is rare and the associated hypercalcaemia is often resistant to all treatment. A case is described in which prolonged control of hypercalcaemia has been achieved by infrequent infusions of pamidronate despite continuing hypersecretion of parathyroid hormone.
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PMID:Prolonged remission of hypercalcaemia due to parathyroid carcinoma with pamidronate. 818 61

Parathyroid carcinoma occurs in 0.1 to 5% as the cause of primary hyperparathyroidism (HPT). It is difficult to determine the true incidence, because parathyroid carcinoma is diagnosed too often due to unreliable histologic criteria. It is only justified to make the diagnosis, when a local recurrence or metastases with the clinical picture of a recurrent or persistent HPT occurred. Treatment of choice is the initial en-bloc resection, which may result in long disease-free intervals. Pharmacological treatment, chemotherapy, and radiation are mostly ineffective in the treatment of parathyroid carcinoma. A satisfactory long-term palliation can only be achieved with repeated resections of the local recurrences and metastases. Diagnostic efforts should be made to localize the recurrent tumor before every reoperation, whereby ultrasonography of the neck is the most sensitive procedure. Occasionally the parathyroid tissue cannot be identified in spite of preoperative diagnostic studies or hypercalcemia persists after surgery. In these cases forced diuresis and medical treatment with calcitonin, diphosphonates or mithramycine can briefly control hypercalcemia. The clinical courses of 3 patients with metastasizing parathyroid carcinoma are presented and discussed. In these patients 3 to 11 surgical interventions were performed in combination with an intermittent medical treatment. By this regimen we achieved long-term palliations up to 13 years.
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PMID:[Parathyroid gland cancer. Problems in diagnosis and therapy]. 846 48

Oxyphil carcinoma of the parathyroid is an extremely rare tumour, only two previous patients having been reported. We report a 55-year-old woman with this condition, who presented with a picture of hyperparathyroidism, including hypercalcaemia, hypercalciuria, hypophosphataemia, increased alkaline phosphatase, and bony lesions. Biopsy of a bone lesion was consistent with brown tumour. Fine needle aspiration cytology and subsequent operative histology of the parathyroid lesion showed an oxyphil cell tumour with malignant characteristics. Following excision, the patient made a good recovery, complicated only by postoperative hypocalcaemia.
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PMID:Oxyphil cell carcinoma of the parathyroid: a rare cause of hyperparathyroidism. 858 61


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