Medline ® Abstract for Reference 42
of 'Hypercalcemia of malignancy: Mechanisms'
Production of parathyroid hormone by a malignant nonparathyroid tumor in a hypercalcemic patient.
Strewler GJ, Budayr AA, Clark OH, Nissenson RA
J Clin Endocrinol Metab. 1993;76(5):1373.
Few cases exist in which the production and secretion of PTH by malignant nonparathyroid tumors have been authenticated. A 69-yr-old man developed hypercalcemia complicating a primitive neuroectodermal malignancy that was widely metastatic. The serum level of intact PTH was markedly increased by immunoradiometric assay (90-290 ng/L; normal, 10-65 ng/L). The serum level of a PTH-related protein was also increased (19-20 ngeq/L; normal,<10 ngeq/L). Exploration of the neck and mediastinum at two operations revealed four normal parathyroid glands. Extracts of the metastatic tumor contained immunoreactive PTH and transcripts of both the PTH and PTH-related protein genes. Thus, hypercalcemia in this patient was associated with production of PTH by a nonparathyroid malignancy.
Endocrine Unit, Veterans Administration Medical Center, San Francisco, California 94121.