Hypercalcemia in patients with breast cancer. Osseous metastases, hyperplastic parathyroid tissue, or pseudohyperparathyroidism?
R. C. Hickey, N. A. Samaan and G. L. Jackson
Breast cancer is the malignant neoplasm most commonly associated with
hypercalcemia. At the University of Texas M. D. Anderson Hospital, Houston,
during the fiscal year 1977 to 1978, of 16,887 patients having calcium
determinations, 7.8% had hypercalcemia. From 1969 to 1979, 13 patients had
proved and three had presumed primary hyperparathyroidism associated with
breast cancer. Two other patients had pseudohyperparathyroidism. Selective
neck vein catheterization was used in 17 of the 18 patients and helped
localize and confirm the diagnosis of primary hyperparathyroidism.
Chloride-phosphate ratios were elevated in 13 of the 14 patients with
proved or presumed primary hyperparathyroidism. This condition may mimic
osseous metastases by producing brown tumors or compression fractures. In
patients with breast cancer and hypercalcemia, particularly without osseous
metastases, a careful diagnostic evaluation is warranted to rule out
primary hyperparathyroidism.
