Hypercalcaemia: malignancy, hyperparathyroidism and benign causes account for different proportions in general and oncology hospitals.

Clinical bottom line (level 4)

Nearly two-thirds of hypercalcaemia is due to malignancy, although three times as many cases are found in oncology centres than general hospitals.
About a tenth of hypercalcaemia is due to hyperparathroidism coexisting with malignancy, although three times as many cases are found in general hospitals than oncology centres.
A third of hypercalcaemia is due to hyperparathyroidism and benign causes, although these will probably all be found in the general hospital setting.

Walls et al: Clinical Endocrinology 1994; 41 : 407-413

Expires January 2004

The study

Setting: one district general hospital and one oncology centre, UK

123 patients (aged ?, ?% male) hypercalcaemia (corrected serum calcium >2.65 mmol/L)

Independent unblinded reference standard, applied in all patients from a consecutive inappropriate spectrum.
Diagnostic test: parathyroid hormone-related protein (PTHrP)and parathyroid hormone (PTH) concentrations in the blood, measured using two-site immunoradiometric assays, calcium and creatinine measured by standard methods, and urinary cyclic AMP (cAMP) measured using scintillation proximity assay.

The evidence

differential diagnosis	number of patients	prevalence (95% CI)
hypercalcaemia due to malignancy	72	58.5% (49.8% to 67.2%)
hypercalcaemia due to malignancy in oncology centre	52	96.3% (91.3% to 101%)
hypercalcaemia due to malignancy in general hospital	20	29.0% (18.3% to 39.7%)
hypercalcaemia due to hyperparathyroidism coexisting with malignancy	9	7.32% (2.72% to 11.9%)
hypercalcaemia due to hyperparathyroidism coexisting with malignancy in the oncology centre	2	3.70% (-1.33% to 8.74%)
hypercalcaemia due to hyperparathyroidism coexisting with malignancy in the general hospital	7	10.1% (3.02% to 17.3%)
hypercalcaemia due to hyperparathyroidism and benign causes	42	34.2% (25.8% to 42.5%)
hypercalcaemia due to hyperparathyroidism and benign causes in the oncology centre	0	0.00% (0.00% to 0.00%)
hypercalcaemia due to hyperparathyroidism and benign causes in the general hospital	39	56.5% (44.8% to 68.2%)

Citation

Walls J, Ratcliffe WA, Howell A, et al: Parathyroid hormone and parathyroid hormone-related protein in the investigation of hypercalcaemia in two hospital populations. Clinical Endocrinology 1994; 41 : 407-413

Contributor: Clare Wotton, January 2000
Reviewer:

_{Clinical Question.}

_Patient	_{hypercalcaemia}
_{Intervention or Exposure}	_{measurement of pararthyroid hormone and parathyroid hormone-related protein}
_Outcome	_{diagnosis of cause}