Calcium infusion in suspected hyperparathyroidism: changes in parathyroid hormone concentration related to histopathological findings.

Changes in parathormone, total and free calcium concentrations in serum were studied in 27 patients with suspected hyperparathyroidism (25 with normocalcemia judged from CaT). Six patients were classified as normals. In 21 patients neck explorations was performed. Patients with definite pathology in the parathyroid glands had higher parathormone, total and free calcium levels than patients with borderline pathology or normal glands. The mean parathormone concentration fell significantly during calcium infusion in patients with histologically normal parathyroid glands. In patients with definitely pathological glands the parathormone concentration remained unchanged during the calcium infusion.