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

Hypercalcaemia is often associated with malignant disease. Causes of elevated serum-calcium levels in the absence of bony metastases include parathyroid-hormone production by the tumour, osteolytic factors made by the tumour, and coexistent primary hyperparathyroidism. By measuring nephrogenous cyclic-A.M.P. excretion to assess parathyroid-hormone function, we have determined the mechanism of such hypercalcaemia in 15 patients. Nephrogenous cyclic A.M.P. ranges from 0.05 to 2.40 mumol/g of creatinine in normal subjects, from 2.27 to 8.45 mumol/g in patients with primary hyperparathyroidism, and from 0.50 to 1.30 mumol/g in patients with proven non-hyperparathyroid hypercalcaemia without malignancy. 9 patients (60%) with hypercalcaemia and malignancy had normal levels of nephrogenous cyclic A.M.P. (range 0.35-2.07 mumol/g creatinine). The other 6 (40%) had elevated nephrogenous cyclic A.M.P. (range 2.70-5.55 mumol/g) consistent with increased parathyroid-hormone secretion. Surgical exploration of the neck in these patients showed that the increased parathyroid-hormone secretion was secondary to primary hyperparathyroidism, not ectopic hyperparathyroidism. Thus, the data indicate that coexistent hyperparathyroidism may be common in patients with hypercalcaemia and malignancy and that the measurement of nephrogenous cyclic A.M.P. is very useful in identifying patients at risk for hyperparathyroidism.
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PMID:Primary hyperparathyroidism in paraneoplastic hypercalcaemia. 7 31

A patient with metastatic islet cell carcinoma of the pancreas, recurrent peptic ulcer disease, and hypergastrinemia (Zollinger-Ellison syndrome) developed symptomatic hypercalcemia and renal insufficiency; she was treated with streptozotocin after parathyroidectomy failed to control her hypercalcemia. Shortly after somewhat less than the usual recommended dose of streptozotocin was administered, the serum calcium concentration fell to near normal with complete resolution of symptoms. Seven months after therapy, mild hypocalcemia, consistent with her degree of renal impairment was noted. However, mild hypercalcemia recurred 13 months after therapy. Shortly after streptozotocin therapy, the mean serum gastrin concentration fell to near normal with radiographic disappearance of the anastomotic ulcer. At 7 and 13 months after therapy, serum gastrin levels were normal. Streptozotocin therapy was accomplished without major complications; specifically, without a detrimental effect on the creatinine clearance. Thus, although hypercalcemia in patients with pancreatic islet cell tumors is often due to associated primary hyperparathyroidism, in some patients it may be due to secretion of a hypercalcemic substance from the tumor and may respond to streptozotocin. Similarly, hypergastrinemia in patients with islet cell tumors may also respond to streptozotocin.
Cancer 1976 Dec
PMID:Pancreatic islet cell carcinoma with hypercalcemia and hypergastrinemia: response to streptozotocin. 13 70

Hypercalcemia is very uncommon in small cell (oat cell) carcinoma of the lung. Two cases of this neoplasm associated with symptomatic hypercalcemia are described. Despite normal skeletal roentgenograms, metastatic bone disease was demonstrated by abnormal bone scans and bone biopsies in both patients. The combination of conventional antihypercalcemia therapy, cytotoxic cancer chemotherapy, and synthetic salmon calcitonin corrected the hypercalcemia despite progression of the small cell carcinoma. One patient with elevated serum immunoreactive parathyroid hormone (PTH) had a parathyroid adenoma at autopsy. This association emphasizes that in cases of bronchogenic small cell carcinoma with hypercalcemia, conincidental primary hyperparathyroidism should be considered.
Cancer 1975 Sep
PMID:Hypercalcemia in small cell (oat cell) carcinoma of the lung. Coincident parathyroid adenoma in one case. 17 Oct 50

Studies of calcium metabolism in 38 patients with cancer indicated that: 1) intestinal absorption of calcium was reduced in patients with skeletal metastases and in those with hypercalcemia; 2) calcium-47 space (a measurement of bone turnover rate) was high in the patients with skeletal metastases; 3) hypercalcemic patients had higher urinary and endogenous fecal excretion of calcium than those who were normocalcemic; 4) levels of plasma immunoreactive parathyroid hormone were similar in normo- and hypercalcemic patients, but the levels for a given serum calcium in malignant disease were lower than those in primary hyperparathyroidism; and 5) some patients had elevated calcitonin levels. Hypercalcemia complicating malignant disease is therefore not due to hyperabsorption or diminished excretion of calcium, and a low calcium diet is unlikely to benefit these patients. Measurement of 47Ca space could be of use in monitoring therapy of patients with skeletal metastases, and measurement of plasma parathyroid hormone could be useful in the differential diagnosis of hypercalcemia.
Cancer 1976 Nov
PMID:Calcium metabolism in cancer. Studies using calcium isotopes and immunoassays for parathyroid hormone and calcitonin. 18 80

Plasma hCT levels were less than 50 pg/ml in 50 normal subjects. In 16 patients with medullary carcinoma of the thyroid (MCT), plasma hCT levels were distinctively elevated and they fell significantly after total thyroidectomy, but in 11 of them plasma levels were still high, indicating the presence of metastases. In 74 patients with the other types of malignancy, plasma hCT levels were found to be high in 9 cases (3 oat cell carcinoma of the lung, 4 malignant carcinoids, one malignant pheochromocytoma and one acute myelocytic leukemia). Except for the leukemic case, all these tumors were derived from neural crest. In 12 patients with primary hyperparathyroidism, plasma hCT levels were less than 20 pg/ml. In 13 hypoparathyroid patients, two with pseudohypoparathyroidism and one with pseudoidiopathic hypoparathyroidism, plasma hCT levels were slightly elevated. Some patients with uremia had elevated plasma hCT levels, but there was no relation between plasma levels of hCT and those of PTH, urea nitrogen or creatinine. In response to Ca (4.5 mg/kg/10 min) or tetragastrin (4 mug/kg/5 min) infusion, a marked increase in plasma hCT was observed in all patients with MCT, but not in normal subjects. In 5 hypoparathyroid patients, a significant increase to both stimuli was also observed in all cases. Two patients with pseudopseudohypoparathyroidism responded to the Ca load. These results indicate that the determination of plasma hCT levels especially after a short Ca or tetragastrin infusion is important to study various pathological conditions.
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PMID:Plasma human calcitonin (hCT) levels in normal and pathologic conditions, and their responses to short calcium or tetragastrin infusion. 19 Dec 50

An assessment of free and total calcium measurements was made in 691 patients with suspected hypercalcemia or disorders often associated with hypercalcemia. In 18.9% of the 1049 specimens analyzed from nine different patient groups, a different impression of hypercalcemia was obtained depending on whether the free or total calcium was considered. Analysis of the ratio of free to total calcium indicated that there are two main factors which influence the distribution of calcium in the serum of hypercalcemic patients: the concentrations of albumin and parathyroid hormone. A lowered albumin concentration accounted for the altered distribution of calcium in patients with malignancies and partially accounted for the altered distribution in patients postrenal transplantation. In patients with confirmed primary hyperparathyroidism a higher ratio of free to total calcium was found, which could not be explained by alterations in protein, albumin, pH, or CO2 content but was related to parathyroid hormone concentration. Free calcium appears to be a slightly better indicator of elevated calcium states than total calcium. Measurements of free calcium should be particularly useful in patients with altered albumin concentration, with multiple myeloma in whom a calcium-binding protein could be present, after renal transplantation, and with suspected hyperparathyroidism and normal or slightly elevated total calcium values.
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PMID:Relationship of free and total calcium in hypercalcemic conditions. 42 92

Hyperfunctioning parathyroid carcinoma is a relatively rare endocrine tumor, accounting for approximately 1% of all cases of primary hyperparathyroidism. The diagnosis is suspected when the tumor is large, parathyroid hormone (iPTH) levels are high, and a palpable tumor is present in the neck. Patients who have recurrence of hyperparathyroidism several months after surgical treatment should be suspected of having a recurrent or persistent parathyroid carcinoma. At operation, a large invasive tumor is usually found. The fibrous, inflammatory-like reaction is the most characteristic indication of malignancy. Even in tumors with minimal invasiveness, the possibility of a carcinoma should be considered if the tumor has mitotic activity and a monotonous instead of a pleomorphic cellular population. If the surgeon can recognize the possibility of parathyroid malignancy and adequately treat the patient during the initial operation, more gratifying results should be obtained.
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PMID:Cancer of the parathyroid glands. 43 61

Rapid differential diagnosis of hypercalcaemia due to primary hyperparathyroidism or malignancy with or without bone metastases may be life saving. A parathormone infusion test (6 USP units/kg body wt X 20 min) enables a differential diagnosis within three hours by means of measurement of renal calcium excretion. In normal persons calcium excretion decreased from 147 +/- 90 to 79 +/- 54 mumol/h (x +/- s, n = 10). In primary hyperparathyroidism with hypercalcaemia the high calcium excretion remained unchanged: 716 +/- 162 mumol/h before and 804 +/- 130 mumul/h 120 minutes after the PTH infusion (n = 12). In patients with hypercalcaemia caused by bronchial carcinoma with (n = 5) and without (n = 1) bone metastases calcium excretion decreased from 552 +/- 182 to 163 +/- 114 mumol/h. As a consequence of these data this test is advisable when the indication for operation in cases with hypercalcaemia has to be reached within a few hours.
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PMID:[Differential diagnosis of hypercalcaemia by measurement of renal calcium excretion during parathormone administration (author's transl)]. 49 90

Various hormones have been implicated in the genesis of hypercalcemia in patients with malignancy. Ectopic secretion of PTH by tumor has been documented in only a few patients; rather, elevated levels of circulating iPTH have been presumed to reflect tumor production of hormone in most patients. Small fragments of PTH, as well as polypeptides larger than native PTH, have been described; their biological roles are unclear. The pattern of immunoreactivity, however, has been used to differentiate patients with ectopic hyperparathyroidism from patients with concomitant primary hyperparathyroidism. Vitamin D-like sterols produced by breast cancer seldom reach plasma levels necessary for physiological effects. Members of the prostaglandin family have been proposed to induce hypercalcemia through osteoclast activation or alteration of the immune system and also to affect the frequency of bone metastases. At present, no direct evidence is available to prove a direct role for these effects and prostaglandins are most useful as possible indicators of disease activity.
Cancer 1978 Jun
PMID:Mechanisms of hypercalcemia in malignancy. 65 92

A prospective series of 200 patients with persistent hypercalcemia had an abbreviated diagnostic work-up consisting of parathormone radioimmunoassay, chest roentgenogram, intravenous pyelography, and serum protein electrophoresis. All patients with hypercalcemia and hyperparathormonism had neck exploration if roentgenograms failed to reveal evidence of ectopic hyperparathyroidism. Serum iPTH proved to be at least 96% accurate in predicting parathyroid disease while at the same time resulting in considerable diagnostic economy. An elevated iPTH was particularly helpful in distinguishing between hypercalcemia due to destruction of bone by malignancy and primary hyperparathyroidism with a coexisting malignancy. Further, measurement of parathormone was useful in evaluation of postoperative hypercalcemia.
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PMID:Serum parathormone in the identification and surgical management of hyperparathyroidism. 70 2


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