Greg, a 42-year-old accountant, was referred for investigation of an isolated elevated calcium serum level found on routine testing.
Greg reported no other medical problems except for two episodes of renal calculi within the past five years. There is no family history of hypercalcaemia.
Hypercalcaemia is a common clinical problem, due to increased bone resorption, excessive gastrointestinal absorption, or decreased renal excretion of calcium.
The two most common causes are primary hyperparathyroidism and malignancy. In their absence, other less frequent causes should be considered.
In primary hyperparathyroidism, hypercalcaemia is due to a parathyroid hormone-mediated increase in bone resorption of calcium, tubular calcium reabsorption and increased intestinal calcium absorption.
Most often, primary hyperparathyroidism is due to a