Absence of Parathyroid Hormone Messenger RNA in Malignant Disease with Hypercalcemia

To the Editor: Congratulations to Dr. Simpson et al. for their exciting article in the August 11 issue,* indicating their inability to detect parathyroid hormone RNA transcripts from tumors associated with hypercalcemia. Such sophisticated evidence that parathyroid hormone rarely, if ever, causes hypercalcemia in malignant disease should help in the occasionally frustrating differential diagnosis between hyperparathyroidism and neoplasia as a cause of hypercalcemia. It is important that subperiosteal resorption of bone is seldom, if ever, seen in the hypercalcemia of malignant disease but, rather, tells us that a given patient with hypercalcemia has hyperparathyroid hormone. Subperiosteal bone resorption should now.