Infrequency of primary hyperparathyroidism in renal stone formers

Repeated measurements of serum calcium and immunoreactive parathyroid hormone were performed in 1433 renal stone formers systematically referred from Accident and Emergency Departments and from Departments of Urology and Nephrology, irrespective of their serum calcium. Primary hyperparathyroidism was found in 23 patients and confirmed in 19/20 patients who underwent neck surgery, including 8 with intermittent hypercalcaemia. Our data suggest that when selection bias is minimised, primary hyperparathyroidism is found in about 2% of renal stone formers in a western country such as Belgium.